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Delayed acceleration

My battery bit it saturday night, and after going through the alternator and battery tests, I replaced the battery. Immediately afterwards, the car started running like . Checking under the hood, I noticed the PCV valve was knocked out, so I placed it back in and that still did not take care of the problem. Long story short, I've replaced all the vacuum lines, the PCV valve, the cap, the rotor, and the car is still running rough at idle and low rpms. There is also a 10 to 15 second delay from a stop before the car will accelerate, regardless of how hard I hit the gas. The car is an 88 cougar 3.8L with 138k miles. I know the egr valve is stuck in the closed position, and am ordering one tomorrow, but I don't want to keep throwing parts at the car. Anybody have any ideas?

Delayed acceleration

Reply #1 –
yes, lots of ideas.

first pull codes explained in my diy link as well as here http://www.foxtbirdcougarforums.com/showthread.php?t=21453&page=2&highlight=buzzer  with a diagram on what to do.

Let us know, sounds really really odd that you have such a long delay in acceleration. Ive never heard of a 15sec delay before, sounds like the eec is shutting down your two injector grounds momentarily and then fires them. 

The only things I know of that contribute to that are the TPS , stator, tfi or eec.

If you dont mind, can you elaborate technically on what you mean by "alternator and battery tests".

also, have you had the car jumped recently?

just quote me and edit the quote with your replies in another color, this can help everyone a lot with a new thread and your responses.

as for the egr, there is a test for it as well in my diy link.  The EVP sensor is just a variable resistor that can be read by any mechanic or any electronics guy.  Go to the electrical tech sticky and get your wiring diagram on the 87evtm page 55 or so.  just look for the pages under EEC for the 3.8 L. The 87 is the same as the 88 for this application.  For the mechanical part of the egr, just suck on the vac line and if the other end holds your tougue for a long while, like a min or two, then the rubber diaphram is not busted.  So, if the EVP sensor reads properly *****WITH AN buttstuffOG METER*** and the diaphram holds suction , then your barking up the wrong tree and its good ole carbon deposits in the intake egr ports that is clogged.  If the egr diaphram can not get crank vac / presure then the diapharam can not move.  If the diaphram can not move then the EVP sensor can not tell the EEC squat and therefore cant use that voltage to do all the math problems required to fire off injectors properly with relation to emissions / efficency only. 

Im gonna bet your root cause is distributor related but pull codes first.  If you get no codes, also let us know.

Delayed acceleration

Reply #2 –
first pull codes explained in my diy link as well as here http://www.foxtbirdcougarforums.com/showthread.php?t=21453&page=2&highlight=buzzer  with a diagram on what to do.

[COLOR="Red"]Just pulled the codes. Immediately after start up it flashed a 3, 4 second pause, dimly flashed a 1, six second pause it flashed a 4, three second pause it flashed a 1, six second pause it flashed a 4, three second pause it flashed a 1. If I'm reading the chart right, system lean fuel control.[/COLOR]



If you dont mind, can you elaborate technically on what you mean by "alternator and battery tests".

[COLOR="Red"]Took the alternator to autozone, they hooked it up to their machine, it tested good. I took the battery to walmart, where I bought it at, and they put it on a load tester. Tested bad in less than 15 minutes.[/COLOR]

also, have you had the car jumped recently?

[COLOR="Red"]Jumped the car to get it home. It did not run poor before the jump, and immediately after the jump I was not paying attention to running conditions, since I was more worried about getting it home.[/COLOR]

as for the egr, there is a test for it as well in my diy link.  The EVP sensor is just a variable resistor that can be read by any mechanic or any electronics guy.  Go to the electrical tech sticky and get your wiring diagram on the 87evtm page 55 or so.  just look for the pages under EEC for the 3.8 L. The 87 is the same as the 88 for this application.  For the mechanical part of the egr, just suck on the vac line and if the other end holds your tougue for a long while, like a min or two, then the rubber diaphram is not busted.  So, if the EVP sensor reads properly *****WITH AN buttstuffOG METER*** and the diaphram holds suction , then your barking up the wrong tree and its good ole carbon deposits in the intake egr ports that is clogged.  If the egr diaphram can not get crank vac / presure then the diapharam can not move.  If the diaphram can not move then the EVP sensor can not tell the EEC squat and therefore cant use that voltage to do all the math problems required to fire off injectors properly with relation to emissions / efficency only. 

[COLOR="Red"]I found out the EGR valve is stuck, I think in the closed position. I'm replacing it tomorrow, and picking up a voltmeter since mine is MIA.[/COLOR]

Im gonna bet your root cause is distributor related but pull codes first.  If you get no codes, also let us know.[/QUOTE]

Delayed acceleration

Reply #3 –
k

did you have a warm engine when you did the codes?
are you for certain the car was finished giving up codes? 
there are two groups with a lenghty pause in between these two groups.  The first group is "whats going on now", the second group is "whats been going on up until now, ie- past 40 warm up cycles".


Now its time to check fuel presure.  refer to the same link in post 2 and let us know what you see.

I find it odd you have no egr code,,dont you?
I also find it odd you do not have other codes. Usually if you have a lean condition, various other related things down the chain will show up as codes but are not the problem.

I also find the 15sec delay odd.

Delayed acceleration

Reply #4 –
The engine was warm, I made positive of that. There could be a second group of codes,it was cold and I was impatient, but I will pull again tomorrow after work to double check. Thanks for the help so far.

Delayed acceleration

Reply #5 –
are you using just a paper clip and the check eng light for codes?

also

there are two tests.,,, one test key on engine off and the other,key on engine running.

redo the KOER
while running there are two groups of codes,, "now" codes and "memory" codes as i like to call them.

then.......

do KOEO
while key on engine off there are two groups of codes,, "now" codes and "memory" codes as i like to call them.

Delayed acceleration

Reply #6 –
are you sure the egr is stuck closed?  a stuck open egr will give very sluggish acceleration.....  also, does a 3.8 have a pip plug?  i wonder if the timing is staying at base and not adjusting, that would hinder acceleration and make it really run like


OOOH!!!  I'm a Eco Hypermiler :burnout: Not bad for 79mph on the interstate 2hours a day

Delayed acceleration

Reply #7 –
I had a set of alligator clips that I was using to run the codes along with the test light. Just got done replacing the EGR, and it's doing the exact same as before. Got to head to work soon, I'll run the KOEO and KOER tests when I get back. I also tested the EVP, or atleast what I thought was the EVP, the sensor attached to the EGR by a 1 inch piece of vacuum line. That is holding pressure.

Delayed acceleration

Reply #8 –
Just finished pulling codes again. KOER method pulled a 41 again, I waited about 10 minutes and there were no other codes. KOEO method pulled a 34 then a 32, waited about 5 minutes this time and no more codes so I assumed it was finished. This was done after replacing the EGR so I'm going to check out the EVP next.

Delayed acceleration

Reply #9 –
sometimes i think im wasting my time but its ok.

you did not test the evp.  You did test the egr.

here is a direct quote from my diy link to test the evp
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)

Delayed acceleration

Reply #10 –
you can simply unplug the EVP and remove it.

there will be a skinny little rod on the end.  as your EGR VAC DIAPHRAM move up and down, it pushes on this rod.

the evp is just like a cieling fan dimmer three wire device.  its a variable resistor just like your tps.

Using an buttstuffog meter will tell all you need to know.

Ill bet you have carbon buildup preventing the egr from working correctly but there might also be another issue. 

can you trace the egr vac line and check it for cracks as well as other major vac lines around the intake.  there are many lines that transition into pvc lines as well.

smog-black and tan lines
red- main crank case vac
green-egr
orange-depends on your engine

Delayed acceleration

Reply #11 –
Alright, sorry about the delay there. EVP sensor tested good, has varying resistance based on the vacuum placed on it. The plug for the EVP sensor is pulling between 4-6 volts like you mentioned. All vac lines I checked were good, and I already replaced most of them when the problem started. There is a green pvc line running from the EGR to a sensor on the passenger side shock housing facing opposite of the firewall. There is also a red pvc line going to this sensor. Any chance this could be the culprit? I went ahead and tested the throttle position sensor while I was at it, and it tested good also.

Delayed acceleration

Reply #12 –
Quote from: badkarate;243225
There is a green pvc line running from the EGR to a sensor on the passenger side shock housing facing opposite of the firewall. There is also a red pvc line going to this sensor. Any chance this could be the culprit? .


I have never trouble shot this part of a 5.0 before but here is what I see going on remotely at this late of an hour.

I see an electrical connector with a red and black wire.

when the electrically operated solenoid gets its control signal ,,ie- either power or ground supplied to it, the solenoid will click.

when the solenoid clicks, a proportioning valve or round do hicky inside the body of the solenoid will move. This will let the red path link up with the green path vac line.

the suction present on the red line (main crank case vac presure) will be able to apply pull vac on the egr through the green path.

the vac on the green line up to the EGR will pull suction on the EGR spring loaded diaphram upwards.  This will move the little rod on the EVP sensor.  Because the EVP is a variable resistor, its various voltages are going to the land of the EEC where the complicated stuff happens and your engine managment system is supervised.


While having all of the above in mind, please understand that if the RED vac line has no vac, it cant pull suction on the EGR.  Getting power to the solenoid does nothing either because the egr isnt moving due to said lack of suction.

I dont have the vac layout on the 5.0 memorized like i do the 3.8 but I seem to remember the red vac line you mention being on the underside of the upper intake which can be gotten to from the rear.(total PITA if you ask me).

If you find you have no vac presure on the red line,,,,and the red vac line indeed does connect directly to the upper intake like i think it does, you just solved your problem.

This is why I tell people to get a can of wd40 and unplug the vac lines off of the electrical mecanical devices that deliver vac presure to sensors.  Just unhook those various solenoids and spray wd40 in them. IT will lub up the inside and free up any moving parts that suffers from age or soot/corrosion buildup.  The electrical portion of the solenoids is (should be) naturally separated from the vac portion of the device otherwise there would be a constant vac leak.

While you are at it, dont forget to unhook the big line going into the driver fender well.  That leads to a nother huge ufo shaped vac diaphram that operates your cruise.



.....back to topic

you may need to remove your IAC like mentioned or at worse case, take off and clean out your intake where these vac lines are connected.  Its like a bee hive of fittings in there with many options for clogging up.  also remove your PCV and clean it.  You might be able to use the existing **FAR END ** connections of all the vac lines on the intake as a path to blow air into. If the intake is clogged at the bee hive of vac fittings on the intake, blowing air might be a permenant solution.  You should see instant results at your red line leading up to the EGR solenoid.

I am going to look at the evtm now to verify a couple of things on the egr solenoid. 

To be honest with you, many of us never had any issues deleting the egr so I am not really sure what your problem will end up being..... all i can say is a 15sec delay is huge.

ONE OTHER THING,,,, disconnect your little sprout connector on your distributor.  It will be a little yellow like pig tail with a shorting plug installed. 
Remove that bugger then start your car and drive like that.  See if your porblem persists.  What you are doing is running your car on "open loop".  The EEC will use basic presets in order to manage your engine and performance. 
The purpose of this is to verify your EEC is involved with the problem.  Not to say the EEC is bad, we just want to eleiminate it for a few moments and see what happens. 

((DO NOT unplug / plug the sprout with the engine running or key on ever))

Delayed acceleration

Reply #13 –
Mine is the 3.8, so no worries about checking into everything 5.0 related. Just disconnected the pigtail, and it ran the same, I could not tell any difference, so hopefully that eliminates the EEC as the problem. I'm on my way to the store to pick up some wd-40, and I'll pull codes again tomorrow morning, see if there have been any changes. Again, thanks for the help you've given so far, I'd be banging my head without it.

Delayed acceleration

Reply #14 –
Quote from: badkarate;242897
I also tested the EVP, or atleast what I thought was the EVP, the sensor attached to the EGR by a 1 inch piece of vacuum line. That is holding pressure.


This doesn't sound like an EVP to me. Sounds like a PFE (pressure feedback) sensor. Anybody have dospoogeentation for 88 3.8?
Code 34 may mean excessive exhaust backpressure.