351w virgin under the hood (SOLVED)

Topic: 351w virgin under the hood (SOLVED) (Read 2843 times) previous topic - next topic

351w virgin under the hood (SOLVED)

February 25, 2005, 05:02:52 PM

Looks like the wife has problems with her bronco. she says it seems to stall out on her when she pushes in the clutch. I toyed with it yesterday late eve and decided i better start getting familiar with this thing. I guess ill start by seeing if it will pull codes and if so, dig up the info.

interesting thing i noticed on this engine,, the location of the TPS is outragious!!!!!!!!!!!!!!!!!!!! Mounted upside down on the second lower throttle body,,wtf.

The wife claims that just before it stalls, the voltage needle shoots up above normal,,,,

EGR isnt clogged and it operates as well with vac applied
ill check the alternator output and test it
try to fiddle with the green wire on the tps for output.
PVC is clear
removed airfilter,, no change in symptoms

Im not sure what this will end up being because its all factory with all the emissions wing dings still on ect ect ect.

Re: 351w virgin under the hood

Reply #1 – February 25, 2005, 11:30:00 PM

Yeah, I've seen the TPS on those things. At the zone we sell alot of them two...

Also check for critters under your intake.

Re: 351w virgin under the hood

Reply #2 – February 26, 2005, 08:16:46 AM

Quote

The wife claims that just before it stalls, the voltage needle shoots up above normal,,,,

Then the computer goes "AAAAAAAAGGHHH! None of my sensors are giving me normal readings, and I don't know what to do!!!" and shuts down?

Re: 351w virgin under the hood

Reply #3 – February 26, 2005, 01:38:42 PM

Ok,, i drove it today and after a good while it finally started doing what she said (dont wanna imply the wife is nuts or anything so i know best how to stay on her good side

)

While the clutch is in and held in, the r's go down
the r's go way below 500 rpm then bounces back up
the alt tries to fall on its face but comes back up.
About the time the alt is at peak, the r's come back up
this cycle repeats (r's up and down, up and down) till either the engine stalls or the idle levels out.

It never stalled on me but the wife still aint crazy

what i did notice is that when i push in the brake and hold the clutch, the engine reaction is a bit more pr0ne to a stall.

So i guess since the r's try to recover then the IAC is doing its job.
I did notice the the egr diaphram was not moving when i maually worked the throttle linkage.

i'm going out to pull codes now,, I wanna pull codes then isolate the emissions vac lines and factor them out to see if it idles better. It has always had a "sort of" miss since we got it.

Re: 351w virgin under the hood

Reply #4 – February 26, 2005, 04:01:04 PM

thats pretty cool,, my bronco gave up codes nicely. I used a 12vdc buzzer instead of a test light.

here are the hard faults......
56 Vane Air Flow(VAF) or Mass Air Flow(MAF)sensor high - VAF MAF
91 (R, M) System running lean - Fuel control
92 (R) System running rich - Fuel control
93 (O) Throttle linkage binding or bad ISC motor ISC (R) HO2S not reading - Fuel control
94 AIR system inoperative - Air Injection
99 (R) ISC needs to learn (Let idle for 2 minutes; Erase memory and retest)

here are the memory faults.......
33 ALL - (O, M) EGR did not open/ respond during test or if memory code, did not open intermittently - EVP EVR PFE
56 Vane Air Flow (VAF) or Mass Air Flow (MAF) sensor high - VAF MAF
67 Park/Neutral circuit fault - PNP
99 (R) ISC needs to learn (Let idle for 2 minutes; Erase memory and retest)

Any takers on a bad fuel pump?
the code 67 is probably cause i converted to 5speed
and the egr code,, Wonder if that thinamagig on top the egr is bad?

am i on track?

Re: 351w virgin under the hood

Reply #5 – February 26, 2005, 04:29:06 PM

It may sound too simple, but the first thing I'd check are the battery cables and ground straps. Also check for a wire harness that may be getting pinched when the engine torques up. The engine moving about when load is applied/removed might be breaking a circuit somewhere. I mention this because of the volt gauge spiking...

Re: 351w virgin under the hood

Reply #6 – February 26, 2005, 06:23:12 PM

i moved on to vac lines using my vac pump,, very complicated in this engine bay but if you stare at it for a while, its pretty easy.

I ended up finding the pinkish tan vac line coming from the TAB solenoid was cracked down at some sort of emissions diverter valve coming off the smog pump. I found it because when i went to remove it, the line broke in my hand. The other lines were not British cigaretteile so i put the actual break under a magnifying glass and it appears that the break had been there for a great while. The crack had dirt / dust build up. I guess when i grabbed it for removeal, it finally broke off completely.

Now the egr moves when slight throttle is applied.
Engine is running smoother now
The tac does not bottom out then try to recover
the tac drops and stays at 800.

maybe its fixed, the wife tested it but she gonna give it a couple more days.

If it is fixed, im gonna remove my tester when the codes are being dumped out to erase the eec memory. Ill let it run for a few days then retest to see if more codes are present.

thunderchicken-
yeah, i know what you mean about the alt pegging,, the reason why i did not think it was that is because it droped proportional to the tac ie-low then high. I had the charge system tested today as well prior to all this .

Based on the codes i listed,, does this vac line being broken seem to make sense to anyone more experienced than me as to why the egr as well as rich/lean codes were present?

im pretty sure its fixed , i hope

Re: 351w virgin under the hood (SOLVED)

Reply #7 – February 27, 2005, 02:37:44 AM

When the cars air/ful or Mass air sensor triggers or even when the Air Injection code triggered... it could cause you to get the lean/ rich codes. It's messed up cause the vacuum line wasn't applied. Most the codes you get are just codes you get when something else dies in the same circuit. Like if you get an misfire in your engine, you might get a system to rich in your O2 code... but you normally wouldn't get a code for a misfire with our older vehicles. i think. i'm not educated though.

Re: 351w virgin under the hood (SOLVED)

Reply #8 – February 27, 2005, 05:00:12 PM

today i pulled the codes again and all the same codes were present except for two new ones.

21 Engine Coolant Temperature (ECT) sensor out of range - ECT
24 Intake Air Temperature (IAT) or Vane Air Temperature (VAT) sensor out of range - IAT VAT

I knew id still have all the old codes but was surprised to see 2 new ones. During my test today, i interupted the system by removing the jumper wire.
I will let her drive it around a bit more and ill pull the codes and see what still stands. According to the instructions, if you remove the jumper during the test, the ecm memory will be erased and the computer starts over again. ,,,so thats what i did.

i feel so close to code 11 but ill keep on plugging away. :D

btw,, using a buzzer instead of a light is much easier cause all you have to do is listen while your write.

Re: 351w virgin under the hood (SOLVED)

Reply #9 – February 28, 2005, 04:59:35 PM

21 and 24 codes, you may not have let it warm up enough before you ran the tests.
Try disconnecting the battery for a few minutes. Then start and let it idle for a few minutes to see if you can clearup the 99 code.

Unplugging the jumper while running the KOEO test will reset the memory codes. So will disconnecting the battery.

The TAD (thermactor air divertor) vacuum line controls whether the
Smog pump air is put into the exhaust system upstream or down stream from the O2 sensors. I suspect if the air is not going where the EEC "thinks" it is, it could screw up how the EEC interprets the O2 sensor reading.

The priorty sequence for multiple codes is to start with the first KOEO code and work through them one by one in order. Then the KOER codes.