[willaby]

My sister has a '94 v6 (3.8L) stang, which has been running very poorly lately. My parents took it in to a mechanic to try and get it fixed, but so far he's stumped. I haven't driven it in a long time, but supposedly this is what it's doing:

-When it's cold: the car starts, but barely runs (acts like it'll die, i guess); if you give it gas, it either dies or almost dies
-Once it warms up, it's not so much of a problem, but it still runs roughly

So far, he's replaced the fuel pump and filter

He plugged his computer into it, with these results:

-it told him the oxygen sensor was bad - replaced it
-told him the TPS (throttle positioning solenoid, what controls how much throttle is applied) was bad - replaced it
-the car's computer was causing the analyses device to blink and reset; the ford dealership's was doing the same thing, so he replaced the car's computer

All these things he has replaced so far have had no effect whatsoever, and they've cost a lot of $$$.

My dad says the exhaust smells very bad too, like rotten eggs, but I think that sounds like a bad catalytic converter, and is unrelated to the other problem.

Anyway, if any of you have heard of a problem like this before, or have any more ideas, I would appreciate your help.

Thanks.

EDIT: the only thing the mechanic can think to do next is replace the fuel injectors, but that requires the removal of the intake manifold etc. etc. and is a big job. They don't want to do that quite yet.

[mustangtk]

IAC solenoids go bad all the time and cause a stall problem especially when cold. Sometimes the rubber diaphram in the fuel pressure regulator ruptures, causing too much fuel to enter the engine. Does the engine have alot of white smoke when starting or driving? The head gaskets could be beginning to fail. Many things can be a source for trouble on older cars, I'd try cleaning the injectors before replacing them. Have the spark plugs been replaced? The change interval is 60k miles for original plugs. The new plugs from Ford (Motorcraft) can go 100k, because they are full platinum plugs (platinum on the center electrode and the ground electrode). Your first mechanic sound like he's just "throwing" parts at your car tryning to fix it. Take it to a Ford dealer and ask that a EEC (pronounced EEK) qualified tech look at it. I work at a Ford dealer and we see all types of strange driveability problems. We had a 96 Mustang with a stalling problem that turned into a no start problem, down by where the driver's left goes is wiring harness. Some change had fallen down there and combined with some water had corroded the wiring going to the PCM. Sometimes good luck is needed to find a problem,but most of the time experience helps more.

[willaby]

>>Forwarding reply to my dad, who knows more about the problem (but is much less computer literate) than me. As soon as he gets back I'll post further information.<<

[newstangownr]

I'm betting that the exhaust is clogged. If your cats are clogged, then it will do as you describe - barely runs when cold, better when hot. Let us know if/when you get this resolved. I'd love to know what the real problem was.

[Yacov]

My truck did the same thing. I was told that it was the 'Cold Start Injector' or something like that. I just lived with it because it wasn't that bad. *shrug*

The truck was a 91 Ranger 3.0 Auto

[Mustangdewd3.8]

I'm having a similar problem right now with my 94. If I don't drive it awhile or just let it sit over night in the morning if i just regulary start it it will start up iodle then soona s it gets to 500 rpms the thing just drops and dies and eventually starts up again like the computer isnt giving enough fuel to ratio and it cant start. now if I start it agan give it gast and keep it at like 1500 rpms for awhile like a minute it won't die. and if it starts normally everytime i tap the gas the engine will make no sound and have a sort of delay. the engine itself only has 3000 miles on it. I didnt change anything on it. I do have a CEL and at first it was No codes Present. then it was err. what did it say the next time! I forget I think it was undocumented code? I'm thinking it's electrical. so I was going to take it to this electrical guy i know, works on electrics like it's his job... well it is haha. hopefully he can snuff out the problem but I am confused right now i checked everything. but if any of you guys have ideas let me know. btw after the initial start the car will start fine for the rest of the day. It's weird.

[kscoyote]

Originally Posted by Mustangdewd3.8

I'm having a similar problem right now with my 94. If I don't drive it awhile or just let it sit over night in the morning if i just regulary start it it will start up iodle then soona s it gets to 500 rpms the thing just drops and dies and eventually starts up again like the computer isnt giving enough fuel to ratio and it cant start. now if I start it agan give it gast and keep it at like 1500 rpms for awhile like a minute it won't die. and if it starts normally everytime i tap the gas the engine will make no sound and have a sort of delay. the engine itself only has 3000 miles on it. I didnt change anything on it. I do have a CEL and at first it was No codes Present. then it was err. what did it say the next time! I forget I think it was undocumented code? I'm thinking it's electrical. so I was going to take it to this electrical guy i know, works on electrics like it's his job... well it is haha. hopefully he can snuff out the problem but I am confused right now i checked everything. but if any of you guys have ideas let me know. btw after the initial start the car will start fine for the rest of the day. It's weird.

get some computer cleaner spray, and spray your MAF sensor, DO NOT TOUCH IT.

It worked for me on my 98 and my 2003.

The computer can't record a code, when it thinks it's adjusting the Air/Fuel ratio correctly. A dirty MAF confuses the computer. Especially when it's cold.

[Mustangdewd3.8]

Originally Posted by kscoyote

get some computer cleaner spray, and spray your MAF sensor, DO NOT TOUCH IT.

It worked for me on my 98 and my 2003.

The computer can't record a code, when it thinks it's adjusting the Air/Fuel ratio correctly. A dirty MAF confuses the computer. Especially when it's cold.

In the better term of my life of working on car engines I never heard of such a thing.

KS you amaze me yet again! I'll get right on that durring my break!

I forgot all about these lil things I gota get back to the books an read up on these things again.

[buddy0506]

I have a 94 3.8 Stang. I just had a motor from a 96 3.8 swapped into it. I think the IAC went out, but when I bought a 96 IAC, it won't work because the harness is still for a 94. Should put the 94 IAC on the 96 3.8? or Should I get the correct harness and attach it to the 96 IAC? Please hurry

[chris12398]

rotten egg smell is usually always caused by a bad cat, or a bad battery. If its the battery you'll see a bulge in it. If so it could explode. That would cause a performacne problem. Im going to go along with the cat's.