Car dies randomly at idle

[Koniz]

Now I am just quoting one of my uncles good friends that is has been a mechanic for 30+ years and he was saying on the 302 distributers the stater will go bad and sieze up on the shaft and that would make those same symtoms I have the same problem with my 94 that is a stick when it dies I usually start and it will try to die and I will wrap the RPMs to about 4000 and it will be fine I would try that

 

[Stanger007]

Here's the laundry list of what I've changed/cleaned:
IAC (did this tonite)
ECT (in intake)
ACT (in intake tract)
New O2s
Cleaned air filter (cleaned MAF a couple of weeks after reoiling)
New Fuel Filter
New Distributor
New Coil
New Plugs (at .054)
New 9mm Ford Racing wires
MSD Cap/Rotor
Fuel Pump (added gauge too see above post)
Cleaned MAF
Cleaned T/B
New PCV Valve/Filter/Grommet
Good grounds
New negative cable
No vacuum leaks
Timing rechecked tonite - at 13-14
No codes last time I checked (2wks ago)

98% of the time it idles great. Rock steady. Love it.

Then there's that 2% where (almost ALWAYS when warm) I start it and put it in gear and the RPMs go up to about 1000 and down to about 450ish and unless I give it a touch of gas it dies. It will also occasionally die at a stoplight just like someone turned the key off. After dying it *always* cranks right back up with no problems.

 

[DoHcHoLlIdAy01]

Here's the laundry list of what I've changed/cleaned:
IAC (did this tonite)
ECT (in intake)
ACT (in intake tract)
New O2s
Cleaned air filter (cleaned MAF a couple of weeks after reoiling)
New Fuel Filter
New Distributor
New Coil
New Plugs (at .054)
New 9mm Ford Racing wires
MSD Cap/Rotor
Fuel Pump (added gauge too see above post)
Cleaned MAF
Cleaned T/B
New PCV Valve/Filter/Grommet
Good grounds
New negative cable
No vacuum leaks
Timing rechecked tonite - at 13-14
No codes last time I checked (2wks ago)

98% of the time it idles great. Rock steady. Love it.

Then there's that 2% where (almost ALWAYS when warm) I start it and put it in gear and the RPMs go up to about 1000 and down to about 450ish and unless I give it a touch of gas it dies. It will also occasionally die at a stoplight just like someone turned the key off. After dying it *always* cranks right back up with no problems.

I still think a tune on the CPU is needed. The stock Ford CPU has problems with it from the factory. It is not too expensive to have a custom chip burned.

 

[blackEagle]

Here's the laundry list of what I've changed/cleaned:
IAC (did this tonite)
ECT (in intake)
ACT (in intake tract)
New O2s
Cleaned air filter (cleaned MAF a couple of weeks after reoiling)
New Fuel Filter
New Distributor
New Coil
New Plugs (at .054)
New 9mm Ford Racing wires
MSD Cap/Rotor
Fuel Pump (added gauge too see above post)
Cleaned MAF
Cleaned T/B
New PCV Valve/Filter/Grommet
Good grounds
New negative cable
No vacuum leaks
Timing rechecked tonite - at 13-14
No codes last time I checked (2wks ago)

98% of the time it idles great. Rock steady. Love it.

Then there's that 2% where (almost ALWAYS when warm) I start it and put it in gear and the RPMs go up to about 1000 and down to about 450ish and unless I give it a touch of gas it dies. It will also occasionally die at a stoplight just like someone turned the key off. After dying it *always* cranks right back up with no problems.

Have you checked the TPS and/or TFI modules? You say the idle goes to 1000 RPM then drops to 450. Mine did the same thing except it would jump to 2500 and drop slowly. It was the TPS tahe was causing it.

 

[Methodical]

Maybe you ignition coil. If you still have your stock ignition coil put it back on and see what happens. My MSD coil has gone bad and I was having starting problems. Peace

 

[Stanger007]

The new IAC didn't help at all. Car is still wanting to die upon into gear on a warm start.

Thanks for the replies - haven't checked the TPS - is there a way to check it without replacing it? Buying new parts is getting old.

I will swap on the old ignition coil tomorrow and see what happens.

 

[HISSIN50]

Thanks for the replies - haven't checked the TPS - is there a way to check it without replacing it? Buying new parts is getting old.

Might give this a read.
Good luck.

 

[DoHcHoLlIdAy01]

If you end up changing your TPS, there are two different part numbers available. Just keep your stock TPS handy for the part # (just in case). But I don't think that will solve your problems. 94-95 mustangs do not respond well at all to any engine mods. Just find a local programmer and ask him if there is anything he can do (to the computer) about this problem. With all the money you have spent on sensors you could have gotten a chip. Sorry don't mean to push the chip, but I went through the exact same things with mine. A big headache.

 

[Stanger007]

Thanks for the help again guys - if I have time today I'll be swapping the coil, checking the TPS and running codes.

Anyone think the MLPS (senses what gear you are in) could be at fault? I bought two books on troubleshooting and tuning the Ford EEC and the description of the MLPS is that when the car is put in gear it tells the EEC to idle the car up to avoid a bog.

So dohc, do you know what the chips are changing in the EEC when they burn a chip? I ask since I will most likely get a twEECer RT instead of a chip.

 

[DoHcHoLlIdAy01]

So dohc, do you know what the chips are changing in the EEC when they burn a chip? I ask since I will most likely get a twEECer RT instead of a chip.

Your car obviously has different parameters in the CPU when running hot rather than cold. For one, you can run your fan earlier (keep cooler). I totally forgot that you can run Tweecer when the car is running. You might get the car to die at idle while tweecer is logging. That would be your best bet, if you know how to program.