Hey all,

I have run into a big problem. I was driving my 96 Z28 today, just cruising along, and bam, car shuts off. While still rolling about 50 mph, I start the car back up. It continues to run for about 20 seconds and then shuts off again. I coast into a small park and continue to try and crank the car for about 5 minutes. I let the car sit for another 5 minutes, then try to start it. To my surprise, it starts right up with no problem.

My girlfriend calls me to come pick her up because her 4-runner broke down... I take the car up there, and get her going. On the way back home, the car just shuts off again... This time, I have to let the car sit for 15 minutes before it will start again. After 15 min, it fires right up w/ no problem. I make it about 2 miles down the road... then bam, shuts off again. I do this all the way back to my house (1:45 minutes later). I'm figuring, off the top of my head, that's it the coil, considering the opti is new (within the year) and it's only doing this when the car gets "warm". Replaced it this evening, and car still does the same thing. It's to the point now in my garage, that I can start the car, it runs for 15-45 seconds, then sputters out.... This is after waiting at least 5 minutes each time. One thing I did notice is after the car sputters out, sometimes the injectors will all start ticking randomly when the engine is not running? The fuel pump is turning on when I turn the key, and one more thing... if I pump the gas pedal, or hold it down, sometimes it changes the condition on whether or not the car starts right up. I don't have a code scanner, and I can't make it up to anywhere to get the that checked...

I actually sold the car to someone, but I refuse to even consider trying to give them the car like this. I need the money from the sale to go back to school, so the sooner I figure out what this is, the better.... Anyone have any idea what it may be? Or any leads in the right direction?

Thanks all,
Eric

 

my car had similar simptoms when the fuel pump went. you can get a fuel pressure gauge from most autoparts stores, borrow one whatever, then connect it to the valve on the fuel rail under the cowl. then tape the guage to the windshield so you can see it while you drive, and see if the pressure drops when the engine shuts off.

 

Is the opti a GM?
I just went thru a prob that was 'heat related' [car warmed up then shut off almost like key was shut off ] after about 10 mi local driving..
At times tach jumped wildly.. [KOEO]injectors ticked.. no other symptoms.
NO DTC's set..
Beat my brains out on it.. bit the bullet got a new opti [new GM] and ICM..
Changed the opti first, prob solved..
Moral of story.. failing opti doesn't always set DTC..
Car ran OK til it got warm... let it cool off, and it started right up, and ran OK[til it got 'hot' again] Drove me nuts for a week..
My thought is a connection inside opti was bad, and when it heated, it broke the connection..
Check the connectors to the opti ICM coil etc for corrosion[mine were good/clean] that can cause it also..

 

I was leaning towards the opti also, yes it is a GM opti.... I am just confused on how/why the injectors are ticking after the car died? Is there a known reason on why a car would do that? (Sometimes they tick/pulse for up to 30 seconds after the car died)

I might just have to go try an opti...

I have to work a good ol' 13 hour day today, so keep 'em comming! I'll check everything out when I get off of work.

Thanks
Eric

 

Only thing I can think of, is a bad connection inside the optical portion that was making just enough to fire injectors repeatedly [remember the wildly moving tach too!also check gages light came on, and SES too tho not every time, or for long.. remember NO DTC's[odd but true] when an 'open slot' of the opti was in just the right place[it didn't do the wild 'injector firing' or 'tach moving' all the time, just on occasion after an attempt to restart], but under actual ignition load, it won't run the car.. a few weak sputters is all if that..
I thought fuel pump too at first.. but it was fine..
I tested fuel pump/pressure, unhooked MSD box, swapped ignition coil, checked all connections, weatherpack connectors etc, grounds by the coil/ICM[I believe that's PCM ground also] to no avail.. That's why I went with opti/ICM..
Was a hard one to diagnose too.. once it cooled off it ran OK tho..
I more or less did opti to 'rule it out' but it ran well after I changed it.. it's been over a week now, no probs.. [I had gotten an ICM also but it wasn't that.. I waited a few days and swapped it anyway also..]
Just another observation, I recall it ran a bit 'off' before the opti swap also..
Only way I can describe it is sort of like with a high stall converter, or imagine a balloon under your foot [gas pedal] sort of 'mushy' and unresponsive?[hard to explain really]
It's a lot better now..

 

Drive the car around for a while with a friend until it does this again... immediately get out of the car and pull off a plug wire.. have your friend try to start the car as you look for spark at the wire. This will let you know whether or not you are dealing iwth a spark or fuel problem which is a pretty big clue. I have never had this happen to my car but other people who have said a new ICM solved it.

 

I will put $50 on the opti, the SAME dam thing happened to my car and I thought it was the fuel pump over heating, but no it was the OPTI, its always the opti

 

Hey all,

I got a scanner to my house and found out that I was pulling a 1371 lo-res code.... Pretty much, I am going to say it's deffinately the opti (even though it has less than 10k on it ) So I'm going to change that tomorrow and see what happens...

Thanks,
Eric

 

I just had the same problem last night. It would get warm and die, cool off and run. Took me two hours to get it home. Opti is about 500miles old. Did your new opti fix your prob?

 

I'm with Brad. I would look into the fuel pump or the ICM.

 

i would lay money on the fuel pump

 

Im also getting the 1371 low res code. As for the pump, it was replace with the Racetronix kit about 4 months ago. Shortly after that i had to replace the ICM, but pulled it from the 140k mile '96 in the back yard. When I did get it to start (last night), my friend following said he saw white, early-morning looking smoke and could smell fuel. I also remember getting the 1371 after the last opti replacement (about 500miles ago), on the first start up. Cleared it to see if it would come back and it didnt, till last night. Out af all the info i found through search, almost all say do the opti. "Do you concur?" Thanks

 

Hey all,

Just an update, it was the opti......

Eric

 

Wheres my $50? lol j/k its ALWAYS the opti

 

First observation after reading this..opti sucks, so I got a Delteq
Second observation after reading this...you live in Hilliard? Thats my last name! cool feeling