Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Topic: Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III (Read 33914 times) previous topic - next topic

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #60 – August 03, 2011, 11:53:57 PM

now for the long post of tid bits i want to add,,, since I went through the entire thread up to now....
Most all the below are in my diy link, however I am not a EECIII guru but do have info on it and as i see it, your in great hands as it is with softouch.

Im very familiar wtih the cfi systems and infact I will bet someone replaced your 5.0 cfi with a 3.8L unit. The throttle plates and tunnels are much larger on the 5.0 than the 3.8L cfi.

Your injectors **must be** blue tops,,,,a must!!
Do not mix injectors, yours for the CFI must be low impedence, most multiport injections are high impedence.

Yes your dad is correct, spark should be nearly a bluish white,, no orange allowed.

IM not sure how you ever got the car to run with the fast idle diapharm crashed like that,seems like you should have had a vac leak there , guss you got lucky and the internals didnt allow it. New'er CFI models had a motor controled Idle control motor with an idle tracking switch , its touchy to adjust.

Yes it is normal for the eec to adjust the base timing based on the tables loaded on the eec (firmware load from the factory). IF for some reason the car is running oddly, or needs to react to a problem, it will defer to a generic "limp mode" table and run on an established baseline timing but it does effect fuel economey and emissions.

Info on your TPS.................
tps test throttle position sensor
1 location-- vertical mounted on pass side of CFI with org/blk/grn wires.
Probe the green wire with positive lead of a meter and ground out
the black lead of your meter.

2 turn ign sw on ,, no start

3 the voltage reading on your meter should be around .5-.9 vdc.

4 operate the throttle linkage very very very slowly and note increase in voltage. Your increase should be smooth with no jumping and it should top out at around 4.6 vdc.

notes..
It is best to use an buttstuffog (needle type) meter when doing this step because it will detect flat or open spots on the variable resiseter (tps) better than the digital types.
you can bench test the tps buy hooking up to the green and black then black to org and measuring resistance and the two readings should match. The green wire is the center tap of the variable resistor. The resistance reading will be proportional to what you see in dc volts.

if you find your low end voltage is at or above one volt,, use a chainsaw file to file out the mounting holes so that you can mount and adjust the tps CCw to achieve the "less than a volt" goal.

when installing the tps,, lay it in place but slightly clockwise,, seat the tps then rotate it ccw to line up the mounting screws. There is a little pin up in the likage that will put your tps in a bind if you dont do this correctly. You cant just lay it on and bolt it down any old way.

Info on your fuel pump and stuff.....
Fuel pump testing (intermittant or no pump sound)
(references are made to a schematic but are not shown,,leme know if you need em)

*******NOTE*******
1983 and 1984 model owners listen up!!
Some cars got two pumps. One low presure electric pump in the tank and a high presure pump near the fuel filter. Make sure you know what you have and verify you have one or two.

later models got one single high presure pump in the tank and im sure most cars with two pumps could delet the external one for a single in tank version.

I could suggest what the Shop manual says to do and it might be in your best interest to do so cause it will verify if the pump is actually going bad or not. They say to install a fuel pres tester to the shrader valve and secure the guage to the windshield with tape. Drive your car and observe the fuel presure does not drop below 30psi during the "LABOR" of the engine between shifts. If it does fall below, replacement is gonna have to happen. Driving the car under a load is really the only way to simulate the problem.

I does sound like an electrical issue but here are a couple diagrams to help out. Primary page to focus on is page 54. Page 55 shows that power splice "s532" on the top and is the source or "source splice" of power for your fuel pump relay located at lower right hand front of engine.

Go to the test connector and ground out the tan/light green wire.
turn the ign switch on, this supplies power energize the EEC Relay.
The eec relay will now deliver power to the coil of the Fuel pump relay. (stare at it for a min and you'll see what i mean)
the fuel pump relay will get its ground from the eec.
the pump relay will energize if the inertia sw is closed and the eec pin 22 supplies the ground.

The fp relay yellow fuse link wire will send power to the pump directly if all works as planned.

Your best hope is that the fp is not working while you troubleshoot. This way you can isolate the issue without even getting dirty.
Perhaps checking the fuse link connections up at the starter relay would also be an option while troubleshooting.

With the tan/light green wire grounded and the ign sw on, you can hear the pump run.
If you do not hear the pump run,, ground out the same color wire at the relay in the trunk.
if the pump does run, the eec or the chassis wiring (tan/lg)leading to the relay is defective.
If it does not run still, then apply a 12v power leg to the pink/black
if the fp runs, the relay is defective.
if the fp does not run, its the pump.

Info on your fuel injectors and how to clean.........
fuel injector id
Per the '87 Ford Emissions manual the '84-'87 3.8 CFI uses a green top 37lb inj. The std 5.0 CFI got 46lb blue top inj. while the HO 5.0('84-'85 Mustang automatics)got a grey top 52lb inj. --- by turbocoupe50

fuel injector cleaning...........
remove the cfi from intake
split the cfi in half via three phillups bolts from the bottom.
,, removed the lower injector retainer (be careful on the screw or you will be taping a new hole).

gently pull the injector out (keep track of your smaller orings).

take a pointed tip screw start this screw into the brass bushing just at the top of the injector until it started to grab real good.

grab the screw with pliers and pulled real hard and out pops the injector screen that is molded to the brass bushing.

spray the injector screen assy down with starting fluid or something.

Next, blast it with the air compressor.

insert the screen assy back into the top of the injectors,, turn the injector upside down and tap it on the workbench which will seat the brass bushing part back in its seat.

re-install the injectors and man does make a difference.

the screen assy is only about a half inch long and about 3/16 in diameter. Pretty fragile looking also. I re-shaped the screen on one becase it was a bit sucked together. I re-shaped it with a small ink pen insert.

timing chain slack measure......................
a breaker bar, extention, socket is needed.
rotate the crank the OPPOSITE direction it spins while running.
rotate it until your harmonic lines up with ZERO deg TDC
you have to be exact on where you stop so make sure its at zero.
now, move the crank the the normal running direction very slowly
this should be kind of where the easy / sweet spot is.
continue moving the crank in the normal rotating direction slowly!!!
suddenly it will get hard to move and you must have a good feel for it!!!
this is the stop / go no further point!!!
thats where the rotor button should start to move if you have the dist cover off.
now,, look at the timing indicator and the harmonic
jot down the number on the harmonic that the pointer is telling you.
repeat the test a few times then average them up for the final slop reading.

My car had 300k and the slack was present for 2/3 of that time so these 3.8's
can take some abuse so its up to you.
i dont know what is good or bad,,,just voice what you have found and
determine if you need a new chain/gear set or not.

Various sensors and how to test them...........................
=============================
EGR/emissions solenoids (codes)
Dual Thermactor Air control Solenoid Valve- both should read 51-108 ohms
EGR Solenoid Vacuum Valve Assembly - both should read 32 to 64 ohms
EGR Valve Position Sensor EVP (OR/W to brn/ltgrn resistance is 5.5k with no vac and 100ohms with vac)(4-6vdc on VREF or/wht)
Electronic Vacuum Regulator EVR 30 to 70 ohms (koeo voltage is about 10.5vdc)

============================\
EGR test and EVP sensor test
apply vac pres to egr vac line fitting.
if it holds the diaphram for a long time,, the diaphram is good
remove carbon buildup on egr base as well as egr base plate assy for 3.8l engines

EVP test (egr sensor)
wire id...
EEC PIN 26 "VREF" orange/white (parallels off to map)
EEC PIN 27 "EVP SIGNAL" brown/light green
EEC PIN 46 "SIG Return" black/white (parallels off to self test conn)

disconnect vac line
disconnect elec conn
hook ohm meter up to the VREF adn EVP Sig contacts
hook up vac guage or apply vac to egr
ohm meter should start out at about 5.5k ohms.
as vac is increased to max, resistance should bottom out to no less than 100ohms.

key on, engine off
cap off vac fitting on evp sensor
measure for 4 to 6 volts dc between VREF and SIGNAL RETURN (ground)
______________________________
ECT sensor test feeds the computer
Resistance test pin to pin of the sensor (this is a variable resister proportional to temperature including outside air temp if the motor is cold)
at 50degF=58K ohms
at 65degF=40K ohms
at 180degF=3.6K ohms
at 220degF=1.8K ohms

next clean the end of the sensor with scotch brite ect and retest
if high temps persist, replace coolant temp sensor and ECT as a matched set.
if that does not work, start looking at your coolant system parts.
----------------------
ACT sensor test ,,,feeds the computer
Resistance test pin to pin of the sensor (this is a variable resister proportional to temperature including outside air temp if the motor is cold)
at 50degF=58K ohms
at 65degF=40K ohms
at 180degF=3.6K ohms
at 220degF=1.8K ohms

Map sensor check,,,,,,,,,,,,,,,,,,,EEC IV only but it may help you
Apply vac pres of about 15lbs to the map, if it holds vac, move on to next step

Key on engine off test
map sensor signal output is the DB/LG wire
**compare output of like maps and average thier outputs if possible per the shop manual
**your altitude is proportional to the barometric presure which the map works off of.

altitude in ft / voltage
0-----------------1.59
1000--------------1.56
2000--------------1.53
3000--------------1.50
4000--------------1.47
5000--------------1.44
6000--------------1.41
7000--------------1.39

If output is in range compared to other maps the move on

Plug off map vac line
apply a few lbs vac to map, like 5 to 8
start engine
slowly apply 15lbs vac and hold about 1500 rpm
while in this test, run the KOER quick test
are any map codes present? (ie-22) if no, then your problem is not the map, its another vac related issue.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #61 – August 04, 2011, 12:28:00 PM

Quote from: jcassity;364597

On page 1 you said you had green top injectors.
...
You have the wrong injectors and throttle body.
...
Again, your butterflies on the 3.8L are too small, restrict air flow and therefor may be the one restriction that is causing the surging.

I thought about this too, given the car's weirdness due to the hillbillies. Sometime after that initial post though I found a BOSCH part number list and the injectors are indeed 5.0 CFI application, 5.81 gm/s. My guess is that the color is just very faded and looks green. (Seriously, it looks like the same color as the ones on my 3.8L CFI, but the part numbers are different. The injectors off the 3.8L have the BOSCH number for the 3.8L application and the ones off the 5.0 have the number for the 5.0L application.) I do have a second set of the 5.0L CFI injectors (in a previous post I mentioned a mechanic friend who gave me a throttle body from an 85 5.0L) and I might try those if I can get this bird running in the first place. I know it was running with those injectors, so I have no reason to swap them out yet.

Also, I know I have the right TB because the size of the holes on the intake match the size of the holes on the TB perfectly.

Quote from: jcassity;364597

The 83's had a molded addition to the pass side to groom in the vac operated idle kick down choke thingy.

I have that too and my 85 TB also has the vacuum fast idle kickdown. That system has given me nothing but trouble. It messes up trying to adjust stuff. I'll adjust something only to discover that the cam on the choke was forcing the throttle open way to far during the adjustment. It also has a tendency to get stuck on the 3rd highest cam. I seriously think that the first time I went in to smog the idle rpm was so high because the choke was stuck!

Quote from: jcassity;364597

You do know the fuel pres regulator is adjustable , correct? pop off the freeze plug on top and lookie at whatcha fine!!!

ZOMG! EPIC! ...no, I had no idea, but that's cool.

Quote from: jcassity;364597

to adjust the choke, just wait till the motor is cold, loosen the exterior housing screws, rotate the exterior plastic housing and just when the throttle plates ""JUST START" to open, tighten your screws down in place. thats the same for a carb motor as well.

Okay, but won't that be somewhat dependent on my idle speed setting? So I'll have to adjust that every time I do an idle speed adjustment right?

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #62 – August 04, 2011, 01:14:33 PM

Quote from: jcassity;364599

your in great hands as it is with softouch.

Yes, softouch has been extremely helpful! :D The DS3 alignment info was some fo the best I've come across so far and cleared up a lot of confusion for me.

Quote from: jcassity;364599

Do not mix injectors, yours for the CFI must be low impedence, most multiport injections are high impedence.

Good to know. It was kind of tempting as I do have a bunch of extra multiport injectors.

Quote from: jcassity;364599

IM not sure how you ever got the car to run with the fast idle diapharm crashed like that,seems like you should have had a vac leak there , guss you got lucky and the internals didnt allow it.

My guess is that the diaphragm collapsed in such a way that it sealed off the vacuum passage. Also I've noticed that these CFI cars seem to be able to handle a vacuum leak a lot better than EFI cars. Don't know why, but this car was able to run with only a little bit of trouble with a fair size vacuum leak, while my van (4.0 EFI) with a smaller vacuum leak can't even idle.

Quote from: jcassity;364599

Info on your TPS.................
...the voltage reading on your meter should be around .5-.9 vdc.

Actually it's different for the EEC-III. Because the EEC-III uses a 9 volt reference instead of a 5 volt (like the EEC-IV), the correct voltage is nearly double (about 1.6 to 2.2 V). Also, the TPS on the EEC-III (or at least on this one) is not adjustable. I'm reading about 1.8 V off of my TPS with closed throttle, so I should be good on that front.

Quote from: jcassity;364599

Some cars got two pumps. One low presure electric pump in the tank and a high presure pump near the fuel filter.

I think I have two pumps, but I'm not sure. I do hear a pump come on when I turn on the key and the fuel pressure at the throttle body shrader valve is 39 psi and constant. I also see fuel squirting out of the injectors while cranking, so I think my fuel delivery is working just fine.

Quote from: jcassity;364599

Go to the test connector and ground out the tan/light green wire.

lol. Silly EEC-III, test connectors are for REAL engine control systems! That being said, I do have a sort of test connector. It has three wires in it, two are the TAD/TAB solenoids and one is ground or something. I use it to read codes so I don't have to take the coolant overflow reservoir off. (EEC-III has no OBD so I only have some limited KOER capability).

Quote from: jcassity;364599

Perhaps checking the fuse link connections up at the starter relay would also be an option while troubleshooting.

Fusable links (all the ones I could find anyway) are all good. Did a resistance test on them (and all the other wires) while I had the harness out.

Quote from: jcassity;364599

Various sensors and how to test them...........................

This is pretty much all EEC-IV stuff. The EEC-III uses a different reference voltage and so the outputs are different. I'm assuming (for now), due to lack of available information, that the RESISTANCE values of the various sensors (EVP, ECT, ACT) are the same for both EEC-III and IV. It makes sense to me that Ford would just keep using the same sensors until they ran out of their inventory.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #63 – August 04, 2011, 01:29:12 PM

Now that I'm done responding, here's some updates to the continuing saga:

Somebody, probably my dad, mentioned the neutral start switch. I initially dismissed this as I am getting power to everything and the car does crank and sometimes run for a second. BUT! Having nothing else to do I decided to strip my ignition circuit of "non-essentials" and check my voltages as I removed each extra component in the circuit. Fortunately there were really only two things: the neutral start switch and the instrument cluster. Disconnecting the instrument cluster improved my voltage to the ignition module, coil and EEC power relay in "run", but didn't do much for me in "start". Bypassing the neutral start switch however, oh boy, I gained a whole VOLT of power going to the coil and ignition module in "start" ("run" voltages stayed mostly the same). Spark quality also improved (now is a blue arc, but my dad says it still isn't as bright as it should be), but the car still won't start. So, though I was getting power through the neutral start switch, perhaps the switch is partially closed or wearing out and has a lot of resistance to it?

Even so, I don't think this is my main problem, and I'm certainly not going to pass smog without my instrument cluster. What about the alternator and voltage regulator? Can they cause this kind of "starts but won't run" behavior?

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #64 – August 05, 2011, 12:33:49 AM

those were just quotes from my diy link,, could've been helpful to you if you needed it.

did you notice the part where you do a fuel pump test while driving the car?

you can never ever get a good test with the car just sitting there at idle or even in gear and braking, gotta drive it and watch the pres between gears, nothing lower than 20psi is allowed at highest point / rpm of each gear in my opinion. I am not saying this is your problem, just letting you know.

It still sounds iike your car is runnng in limp mode after you so called "reset the computer".

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #65 – August 05, 2011, 01:26:37 AM

Some voltage and resistance checks from the 84 shop manual.
Coil resistance:
Disconnect the coil connector.
The primary resistance from the Batt to the Tach terminal should be 0.8 to 1.6 ohms.
The secondary resistance from the Batt to the high voltage terminal should be 7,700 to 10,500 ohms.

Ballest resistor:
Disconnect the coil connector and the two wire connector to the ignition module.
The resistance between the module cable connector that goes to the red wire and the batt terminal of the coil connector. It should be 0.8 to 1.6 ohms.

Coil voltage should be 6 to 8 volts on the Batt side of the coil with the ignition in run.

The green wire to the ignition module should be greater than 1.5 volts with the ignition in run. Measure by pushing a pin into the wire.

MASSIVE POST INCOMING (sorry, important stuff in bold)

Reply #66 – August 06, 2011, 12:33:13 AM

Quote from: jcassity;364648

It still sounds iike your car is runnng in limp mode after you so called "reset the computer".

I don't think it is, but it's always possible. I "reset the computer" by disconnecting the battery for a couple hours. Usually having no power for a while clears it. At least that's how it's done on my EEC-IV cars.

Quote from: softtouch;364650

Some voltage and resistance checks from the 84 shop manual....

Those are the same as in my 1983 shop manual. Everything tests fine... well... until today....................(see below)

Quote from: jcassity;364648

those were just quotes from my diy link,, could've been helpful to you if you needed it.

did you notice the part where you do a fuel pump test while driving the car?

you can never ever get a good test with the car just sitting there at idle or even in gear and braking, gotta drive it and watch the pres between gears, nothing lower than 20psi is allowed at highest point / rpm of each gear in my opinion. I am not saying this is your problem, just letting you know.

(BTW, I've now bookmarked that DIY link. Good stuff in there.) It was THIS post that led me to the solution of my current no start problem.....but you guys are going to hate me when I tell you want it was.....

Last night I was sulking in the garage, staring at the car, when I remembered jcassity's post about the fuel pumps and fuel pressure. I'd already checked the fuel pressure before several times while trying to solve the surging and it tested fine, (and I couldn't drive it around at the moment, obviously), but I hadn't done a pressure test since this no start problem began!

Normally that would be first thing after checking the ignition system, but since I saw the injectors pushing out fuel and I had done a test not too long ago (and recently replaced the pressure regulator) I didn't think it would help. My dad came into the garage, saw me attaching the pressure gauge and tried to talk me out of it, saying it was a "waste of time" for the reasons I just listed. But I hooked it up anyway and turned on the key and ... nothing... A paultry 3 PSI. I switched it on and off several times and the most pressure that built up was 4 PSI.

I have to tell you guys: I've never been more excited in my life to have low fuel pressure!

Finally! Something I can DO!

Now for the best bit: It's definitely the pumps.

I disconnected the fuel line ahead of the in-line high pressure pump and I removed the pump relay. I attached a piece of fuel line to the high pressure pump with the other end leading into a measuring cup (capacity of about a liter). I jumpered the fuel pump relay to give battery power directly to the pumps for about 10 seconds and then checked how much fuel went into the measuring cup. (Basic volume test.)

PRACTICALLY NOTHING. About 10 mL. I did the volume test several times, it kept giving me nothing, and then suddenly it just started pumping out fuel like there was no tomorrow. I hooked the fuel line to the TB back up and tried to start the car. It fired right up and ran GREAT! Fuel pressure was about 41 PSI. I let it run for a little, while watching the fuel pressure and waited. Suddenly the pressure started to drop and the car started to struggle at a little under 30 PSI. I turned it off and the pressure stopped dropping. That was a couple hours ago and the pressure is still holding.

My pressure regulator is still good which means I'm not leaking fuel through it into my return line, which means it's an intermittent problem with one or both of the pumps. Now, I'm not going to say that new pumps will solve my surging, because there's no way to verify that yet, but it WILL solve my no start.

That being said I'm looking for some new pumps. I'm thinking of replacing the two pump system with a single high pressure in-tank pump. Right now I'm looking at this High Flow Performance pump: http://highflowfuel.com/i-5210331-hfp-255lph-fuel-pump-ford-thunderbird-1983-1997.html

I feel like if I'm going to go through the bother of dropping the tank I should put in a quality pump that will support any modifications I decide to make to the car down the road (such as SEFI, H.O. CFI, or whatever). AND I want to use just one pump, in-tank, just in case I ever add a dual exhaust. (I'm figuring save time and money later.)

Has anyone used a high flow pump (255 lph is WAY higher than the stock 66 lph) on a stock CFI setup? I don't really see it as being an issue, but I don't want to kill my pressure regulator or new pump due to ignorance.

Special thanks to jcassity and softtouch, thank you for coming on this wild goose chase with me. If you guys are ever in northern CA, I owe you lunch or something. Hopefully when I fire it up with a new pump everything will work perfectly with no surge (fingers crossed).

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #67 – August 12, 2011, 01:41:36 PM

Thought everyone should know the final verdict:

The cause of the surging was the ignition module.

With it running I was able to diagnose it. Put the old module in, idle surging, put the new module in, no idle surging.

With the new module it idles smoothly, exactly where I set it and where CA wants it. The spark advance timing adjustments made by the EEC are a lot smoother too. Before I would watch the timing and it would kind of waver around (it'd fluctuate erratically +/-3 degrees). Now it holds steady and doesn't move until I rev the engine or change gear. When it does change it is a smooth adjustment. So, for the future, if your checking the timing and your mark is moving erratically (looking like it's "vibrating" a bit is normal because of the strobe effect from the timing light) you should check over the whole ignition system. Of course, none of my tests showed there to be anything really wrong with the ignition module, that was just an act of desperation on my part.

Btw jcassity, I'm going to go by the Ford dealer soon and see if I can convince them to look something up for me. I have two stock CA 5.0 throttle bodies with green injectors. One of them I got from a guy who is one of the best mechanics I've ever known and he said that the whole TB was stock, never messed with. He got it ages ago, shelved it for years, and then gave it to me. I'll bet you that CA required Ford to put green top injectors on the CA 5.0s, that's what I'm going to try to find out. I hate this state.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #68 – August 12, 2011, 10:48:44 PM

Thanks for the feedback.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #69 – August 13, 2011, 11:54:59 AM

good news!

ive never seen green top injectors with the same pn as the blue tops, however, this was in the early stages of this body and car design. Ford does tend to change things too often to my liking.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #70 – August 14, 2011, 10:40:38 AM

Quote from: crossalchemist;365047

Thought everyone should know the final verdict:

The cause of the surging was the ignition module.

With it running I was able to diagnose it. Put the old module in, idle surging, put the new module in, no idle surging.

Wow, since I've been away from here for awhile I have a lot of catching up to do! It's great there's been so much information on this subject..thanks to all who helped out.:bowdown:

This is good news, especially since I bought an ignition module recently in order to see if this would fix the surging issue on my 83. In the past I just increased the idle speed when it occurred but not a great fix since it required increasing to the point where I needed to keep my foot on the brake at 'idle'.:hick:

As soon as I get time, I'll fire up my 83 and if it decides to surge I'll have the new ignition module handy and ready to swap to confirm the fix.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #71 – August 17, 2011, 02:35:25 AM

So, I spoke to "my local Ford dealer" about the injectors. The girl behind the parts counter said that the 5.0L CFI injectors for the "CA/NY emissions application" are DIFFERENT than those for the rest of the U.S.

She e-mailed Ford HQ to confirm if a "green top" injector was used on the CA 5.0L engines stock and to see if these are the same as the 3.8L injectors (which are also a different part number). She says she'll give me a call when she hears back from them.

THE PLOT THICKENS.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #72 – August 17, 2011, 03:23:31 AM

Quote from: rodsterh;365107

As soon as I get time, I'll fire up my 83 and if it decides to surge I'll have the new ignition module handy and ready to swap to confirm the fix.

I hope it helps! Of course, just cuz it worked for me doesn't mean it'll fix every EEC-III CFI with an idle surge out there.

I'd say take a look at your timing marks and if they are erratic and jumping around like I described before, there's a good chance a new module will help out.

I would say to follow the following troubleshooting guide:

1) Test all sensors, solenoids and switches (relays). The three 'S's.
2) Check all vacuum components for leaks, including lines.
3) Test continuity and check for shorts/crossover on all sensor and solenoid wires between the components and the EEC.
4) Test the ENTIRE ignition circuit, including coil and plug wires. Do a spark test and make sure the module is getting the appropriate amount of power at the right times and that it is capable of acting on a "spark" signal from the EEC (the orange wire).
5) Check your distributor cap and rotor and rotor alignment.
6) Fuel system tests. Do both a pressure test at the throttle body and a volume test of both pumps, together AND individually. If you get volume, but no pressure, you probably have a bad regulator, but a bad check valve in your fuel pumps is also possible. After the car is off, the pressure at the TB should be held for a pretty long while (my regulator took a couple days to drop to 35). Also check for any kinks in the lines and replace the fuel filter. Clean the injectors.
7) Pull codes from the EEC-III. (I'll post more on my adventures in that happy land later, as I want to go to bed.) Fix whatever it's complaining about, if anything, then repeat this whole process. If it doesn't complain about anything (code 1-1 or no codes) then it could be the EEC module itself. The EEC-III has separate circuits inside the module for different tasks. For example, each solenoid has a different circuit. If you did something stupid while playing with one of the solenoids you'll damage that solenoid's circuit inside the EEC module. The car will still run and the EEC will still do other stuff, but, for example, if you damage the EGR solenoid circuit then the EEC will not be able to open and close the EGR causing you to fail your smog test. This kind of failure will also not give you a code, because the circuit is unavailable to generate the code in the first place. (WARNING: this is all according to some stuff I read, I forget where, but it makes sense if you think about it. I'll try to verify it somehow.)

Rinse.
9) Repeat.
Results may vary. Ask your doctor before using. Common side effects are frustration, skinned knuckles, headache, and loss of brain cells due to exposure to gasoline fumes.

This all assumes that your base timing (cam to crank, set when you first put the cam in and align the timing gears!) is correct, and that the lobes on the inductive ring on the harmonic balancer are still intact and in the correct spot relative to the crank position sensor (one lobe directly under the CPS at 10 degrees BTDC).

ANOTHER THING YOU CAN CHECK is your exhaust system. Make sure the cats or the ler are not partially clogged. Check the weird heat control valve on the left exhaust manifold (if it's stuck closed, you got problems). Clean out all carbon, "far as the curse is found".

I'll add more to this later.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #73 – August 21, 2011, 11:08:29 PM

Great information!

Here's something interesting I found in the Ford "EECIII EECIV Training Program Reference Book"

[COLOR="blue"]=>Microprocessors

==>Engine Idle Speed

Another system, not normally associated with emissions, is engine idle speed control. Since carburetor air/fuel ratios have been leaned to a point where the engine would idle smoothly at higher engine speeds due to emissions, the ECA controls the engine idle speed. The ECA increases the idle speed but, upon engine shutdown, the idle speed is immediately decreased by the ECA.[/COLOR]

This confirms the ECA controls the idle speed and that there is a function to increase and decrease (surge?) the idle based on some input.

Sounds like this circuitry could be the cause of surge.

Idle Surge - 1984 5.0 Thunderbird, CFI, EEC-III, Duraspark III

Reply #74 – March 08, 2014, 05:43:05 PM

crossalchemist,

I came across this thread while searching the web for symptoms and solutions for my temperamental CFI 302 equipped Mercury Colony Park. The vacuum diaphragm in my fast idle was shot and I can't find where to buy a replacement diaphragm. Where did you get yours? Any help from other forum members would also be appreciated.