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I need some direction. Ok one night i was driving on the highway at high speed i suddenly felt a slight hiccup while on the accelerator. As i slowed down the car died and the oil pressure light came on. It has done this before and wouldnt start again. When i pulled over i tried to crank it again and it jus turned over but didnt start. I popped the hood and waited a little and tried again. It started this time.. Then as i was driving about 1 mile down the road it died again and wouldnt start again.
I took it to my mechanic and he ran test on it for about a month, he finally got it running but he says i may need to get the pcm tuned for the 95 motor which is in my 96 caprice.. What could it possibly be?
 

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Check your ignition control module. As they fail, they crap out when they heat up.
 

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I took it to my mechanic and he ran test on it for about a month, he finally got it running but he says i may need to get the pcm tuned for the 95 motor which is in my 96 caprice.. What could it possibly be?
Your mechanic had it for a month to diagnose?

I would suggest a fuel pressure test as a starting point. Might be the fuel pump.
 

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I need some direction. Ok one night i was driving on the highway at high speed i suddenly felt a slight hiccup while on the accelerator. As i slowed down the car died and the oil pressure light came on. It has done this before and wouldnt start again. When i pulled over i tried to crank it again and it jus turned over but didnt start. I popped the hood and waited a little and tried again. It started this time.. Then as i was driving about 1 mile down the road it died again and wouldnt start again.
I took it to my mechanic and he ran test on it for about a month, he finally got it running but he says i may need to get the pcm tuned for the 95 motor which is in my 96 caprice.. What could it possibly be?
"What could it possibly be?"

I would lean toward the Fuel Pump myself, but did your mechanic do a FPressure test OR when it doesn't start do you even hear the pump run? Even that could technically be electrical related due to wiring issues.

So as you can see from the other responses here, it could be any number of things. So it's really hard to answer your question and diagnose this base on what was provided for us to help. Sounds like a lot of unknowns here as well.

You sort of slid in the "95 motor in a 96" car.....oh boy, diagnosing just got waaaay more complicated. No idea what was done, how it was done or if it was even done correctly....i. e. Hacked up wiring, ECM (correct) for how things were done? I also agree that having your car for a month and he couldn't find the issue? Time to find a new mechanic. ;).
 

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Discussion Starter #5
U think it can be the icm? I dont want to keep throwing money into it if thats not the cause..

And yes my mechanic had it for over a month only to find out the pcm wasnt giving enough power to the distributor. Mind you, i had a 95 pcm in previously when it died. But i have a 96 pcm now
 

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U think it can be the icm? I dont want to keep throwing money into it if thats not the cause..
I think it could be but who the hell knows? Is the car running OK now? if so, it's not the ICM...or anything else. If not, what are the symptoms now, not just before you took it to the mechanic?
 

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Discussion Starter #7
Suprisingly the symptoms are none it drives fine and starts right up. But! The last time i drove it around and as i parked it it cut off so idk its very confusing
 

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Yikes. Sounds like this has devolved back to the basics. You certainly don't need any more shop time.

I dint see the part where you checked for DTCs. If 'twer me I'd be wiggling wires and hoping for a bad ground(s).
 

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Yea im leaning towards maybe a bad ground because i dont see anything else wrong.. I started it up and it ran for like 15 mins then finally cut off, but it cranks right back up everytime. Wat would i have to do in order to get it solved
 

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Yea im leaning towards maybe a bad ground because i dont see anything else wrong.. I started it up and it ran for like 15 mins then finally cut off, but it cranks right back up everytime. Wat would i have to do in order to get it solved
Find your loose ground? There is a bundle of grounds on a stud by the coil mount. Verify that the connection there is clean and tight. The fuel pump has a ground in the trunk, by the driver's side trunk light. Verify that's good.

Seriously, a bad ground can cause intermittent issues, but they're usually not as consistent. I'd look for something that's failing. You don't mention if you've actually tested it for anything other than having some shop stare at it for a month. If it's a 96, it's OBDII, so most local parts houses can scan the computer to see if it's tripped any codes... for free. That would be the first place to look.

If there are no codes, I'd hook up a fuel pressure gauge and start and run the car to see what the start/run and run with the vacuum line to the fuel pressure regulator removed from the regulator. That will help rule out a failing fuel pump which is what this sounds like is happening.
 

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Discussion Starter #11
I have a code reader and the only code showing is p1641. Its because i only have one cooling fan the other was removed but thats been there since i had the car.. And this issue just arose 2 months ago. I jus removed the ignition coil and sprayed it with electronic cleaner and tightened it back up.
I started to crank it and it turned over and immediately died. I did it 5 times and on the 5th try it stayed on.. So im thinking its maybe a grounding issue.? Wat u think
 

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... I jus removed the ignition coil and sprayed it with electronic cleaner and tightened it back up.
... Wat u think
Just cleaning it will not restore an aged ICM either reaching its normal lifespan or weakened by overheating/failures.

I trust you used the CORRECT heat sink paste when re-attaching the original part.
 

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Not sure why people don't appear willing to check fuel pressure first,but prefer chasing electrical problems instead. Fuel pressure should be the first thing checked in all,but a few driveability diagnosis. It may not be the problem,but until it's verified one continues to not know...
 

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Yep, Fuel Pump/Pressure and/or wiring issues can be a headache if not checked and checked properly. Even though FP looks good while idleing in the Garage and testing...take the car out for a drive, hit a bump in the road and the car stalls. Ive been there. :(

Could still be a loose, burned up or otherwise comprimised wire in the circuit(s) somewhere. These are old cars with lots of miles and in some cases some crappy wiring to begin with. All we can do is offer suggestions, how someone chooses to follow them is up to that person. Seems like OP has quite a few issues to work with and suggestions to try and figure out and not much more that I can offer from waaaaay over here on the Web. :)
 

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Another thing to not rule out is the opti. I was having almost exact same symptoms. Car would drive fine for days, then randomly die and sometimes start back up and be fine, or start up and move a little and die, or just not start for hours or more. Had a shop go over the basics, fuel pressure was fine. When I first got the car it was my first LT1 and it was having overheating issues so I was constantly bleeding the cooling system, not realizing it was dumping coolant all over the opti which was causing it to fail, once I got that replaced its been fine ever since. Just another option.
 

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Had a similar problem on my 305 TBI. Intermittent at first, then no start. Failed distributor pickup coil. Another time it was the ICM. That would crap out when it got hot.
 
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