car won't run....

[ba#97]

Hey guys so i'm having issues with my 95 cobra. has an msd ignition, msd coil pack and other bolt ons....this issue started slowly with me driving around and every now and then the car would kinda drop rpm to nothing and then hit again and go.....thought oh that's where but thought nothing of it. then driving about 15 through town car just died, after about 10 or so minutes started right up. on my way to the autocross the other weekend....doing 65 down the highway, rpm dropped to 0, car rolled to a stop, wouldn't start at all. towed it home. now she's sitting in the carport. every now and then i try to get it to run and it will start but dies soon after. changed the ignition module, started right up....dies after about a minute. so shot the coil pack, saw an open....ok that must be it. change coil pack, start, nothing, finally let it sit for a bit....starts, dies after about 20 seconds. it dies clean....no stumbles or stutters. msd shows red light solid sometimes and sometimes doesn't? need help.

 

[RED GT95]

Bypass the msd ?

 

[RichV]

Start with the TFI. They do some goofy stuff.

Coil pack? Don't the 95s have distributors?

 

[ba#97]

yes it does have a distributor and i have bypassed the msd on numerous occasions. still does the same thing.

 

[ba#97]

the tfi is what i mean by coil pack....my bad.

 

[RichV]

I would check if the issue is ignition or fuel next. When it won't run/start test for fuel and spark.

Fuel pressure good?

 

[ba#97]

haven't checked the fuel pressure yet but based off of how it just cleanly shuts off it kinda makes me think it's not that....i need to check though.

 

[Musturd]

^ this start the car let it die out on you then check for spark at the coil itself and at the plugs and make sure car is getting fuel

 

[ivan12]

If it was fuel it wouldn't just cut off smooth. It's most likely the PIP sensor in you distributor

 

[ba#97]

i'm afraid to just go off a it's most likely, cuz that's what ive gone off of with the ignition module and coil, the coil was definitely bad though. but i will definitely give it thought and check all these things next time i have a chance.

 

[toyman]

The PIP (Hall Effect) sensor seems most likely. It's failing characteristics are as described and then it will just die. The PIP provides input to the ECU so it knows which cylinder to fire by sending a signal to the TFI (Ignition Module).

 

[CC'S95GT]

Toyman and Ivan nailed it. PIP (aka hall effect sensor) inside dizzy.. You can either replace just the PIP for about $20 but you have to disassemble the dizzy to do it. or remanned dizzy for $120 which can be hit or miss as to whether it will work or not. or a new aftermarket or OEM for $300 ish.

 

[RichV]

the tfi is what i mean by coil pack....my bad.

Just thinking here... the TFI is the fender mounted piece with the huge heat sink, close to the MAF. You have to use the special tool for it. That is what you replaced?

Or was it the ignition coil? I would still verify you have fuel pressure, a pump shutting off will just kill it fast as well.

 

[CC'S95GT]

The PIP inside the dizzy also sends the signal to the FP to keep it running while the engine is running.. The TFI or ignition control module doesn't usually go out like they do on the foxes.

 

[ba#97]

Just thinking here... the TFI is the fender mounted piece with the huge heat sink, close to the MAF. You have to use the special tool for it. That is what you replaced?

Or was it the ignition coil? I would still verify you have fuel pressure, a pump shutting off will just kill it fast as well.

the fender mounted piece is the ignition module. that i already changed. the ignition coil i what i just changed.

 

[ba#97]

would the pip sensor being bad cause it to not start at all from time to time either? it's hit or miss getting the car to start. when it does thats when it cleanly shuts off not too long after.

 

[CC'S95GT]

yup. your having the exact symptoms I had when mine crapped out. It's a common problem with 94/95 5.0's. The PIP isn't picking up a clean enough signal to tell the computer when to fire the spark plug or keep the fuel pump running either.

 

[ba#97]

change the pip sensor then? that would be the easiest thing?

 

[CC'S95GT]

Easist would be to swap the whole dizzy. but the pip is easier if you have the skills and time. The bushing could be worn in the dizzy too and that's even harder to replace, if you could find a replacement.

 

[ba#97]

so do you recommend a redone distributor or an after market?