I was driving across town today and during acc my 94 with a 5.0 started spittin and spuddering. and the more gas a gave it the worse it got. so i pulled over and it was idling fine till i kept given it gas and now its just barley staying alive. i was able to tow it back to the house and started with the basics.
1, checked fuel pressure good
2. fuel pump working like it should.
3. no code being shot at this time
4. played with the timing a little and didn't do a damn thing but make it mad. lol
5. fuses are good and from what i can tell the relays are good,
6. im ?????? the mass air, or TPS,or ignition module, or distributor.
7. iv been think that timing jumped but im not leaning that way.
I haven't checked to see if the rotor is on one with piston one yet but i might start that here shortly.
Ive been looking left and right for the last 2 hours for some insight but haven't really found my prob. that's the only reason for starting new thread.......


oh and i let it cold down for a bit and start it up and it runs really bad but better then this morning..........
I just feel like im missing something....... I wish i can get a video of it up... i might try to get a youtube video and post the link.......
thanks guys mike

 

ok here is the video of it. poor pic sorry but i best at the time.......

YouTube - 94 bronco

 

Have you run a KOEO test? I would lean towards a TP sensor issue but KOEO will give you more insight. With it failing to idle there are going to be some kind of codes generated. Even Code 11 or 111 will at least eliminate the need to chase electronics any further.

 

I don't see any water, but to me it sounds like wet distributer. Did you wash it today?

 

Funny you said that...one of the reasons I got my truck so cheap was because the PO had pressure washed the engine bay. Somehow that trashed the TPS, and because he didn't take the time to pull codes, he had a truck that wouldn't run.

I pulled codes...now it runs!

 

try cleaning the MAF sensor if equipped, and test for good spark on all cyl. kinda sounds like a ign. prob. weak or failing ign. coil?

 

well its not wet by any means. Im gonna go to the junk yard tomorrow and ****** the tp sensor and a couple of other things to eliminate the ign. I don't want to spend $$$ on electric parts that cannot be returned. but i did start it up just a few mins ago and it sound good for 5 sec then started again spitting and sputting again....

 

You could pull codes and not spend any money until you know for certain what, if any electrical problems there might be. Not trying to be a smart-*** here but the EEC-IV STI and OBD-II systems were designed to keep owners and mechanics alike from having to guess at the cause of the problems. Spending ANY money on a part that may be fine seems like a backward approach to fixing the problem. But, its your truck and your money so here's hoping you find the problem.

 

ok i just pulled the codes this morning. i shot a video because some of the numbers are making no since, so i will put it in the skilled hands of you guys.... oh i started it up today and it ran good for about 10 sec and started acting up again.......
YouTube - Video 0003

 

Lets look at the very LAST Code given... Code 542

Code 542 - Indicates that the fuel pump circuit was open on the negative (ground) side of the circuit. FIRST THING! Check the Inertia switch! It breaks the negative side of the fuel pump circuit in the event of a collision however I've seen old ones trip with a good hard bounce. If it has tripped you may need to replace it so it doesn't continue to "nuisance trip" on you. If this is NOT the problem, read on.

I get CM Code 334 - EVP voltage higher than expected. This means one of two things. The EVP sensor had failed OR the EGR valve is stuck open.

But wait, there's more.

Code 157 - after doing a little research on this one because I had never seen it, Code 157 typically indicates voltage to the MAF sensor is low. (Don't deal with MAF in any of my trucks so wasn't familiar with it.)

Code 172 - Indicates a lean condition as determined by the O2 sensor. This pretty much guarantees that the EGR valve is stuck open and the EVP sensor is not bad. Too much air in the mix causes a lean condition as a result of the EGR being open when it should be closed.

Code 211 - This is the BIG ONE. Indicates a failure in the PIP circuit. The Profile Ignition Pickup (PIP) is the "ignition points" in an EEC-IV engine. (Where is g-k50 when I need him?) Unless the distributor wiring harness has sustained some damage and shorted the PIP wiring together, the FIX for this is to open the distributor, remove the rotor, the excitor ring (be extremely careful not to bend or deform this thing) and finally remove/replace the PIP which is mounted to the floor of the distributor casting. IF THE INERTIA SWITCH IS NOT TRIPPED, THIS IS WHY IT WON'T START.

Code 327 - EVP voltage below minimum voltage. Most likely the system trying to compensate for the stuck EGR and shutting the EVP sensor down.

Code 334 - means the same thing here as it did above.

 

Sure am glad I sold my 95 that sounds like a lot of gibberish to this old plumber.

 

Nah, just a more efficient way of troubleshooting. He could spend a week guessing at what is wrong. The codes pinpoint the problems.

 

ok well just got back from the junk yard and wow. I replaced the tps,egr valve, ignition module, cleaned throttle valve and clean o2 sensor and cleaned mass air sensor. not a single change. it will start up, but barley run. it wont throttle up by any means. i pressed down on the fuel rail release valve and it shot 2 ft like it should so i can eliminate fuel... I was kinda leaning towards the distributor. do you guys think the timing might of jumped a tooth. just throwing that out there. i know im getting close.....lol. thanks guys for the support.

 

ok another video........after other parts..
YouTube - Video 0003

 

The answer is in the codes... I posted... you paid for and replaced a bunch of things that obviously aren't the problem. Try this!