I HAVE A 95 T/A LT1.... WAS RUNNING GOOD TILL I DECIDED TO GET MSD COIL.... INSTALLED IT ALSO GOT BRAND NEW ACCEL OPTISPARK AND PUT IT RIGHT ON...... CAR FIREUP FINE AND I TOOK IT OUT FOR A CRUISE, WAS ON THE FREEWAY GOING 70 CRUISE CONTROL... WHEN SUDDENLY CAR TURN OFF AND NEVER STARTED AGAIN TOWED IT HOME..... GOT NEW SPARK PLUG WIRES, SPARK PLUGS, ICM, AND OPTI PIG TAIL... STILL NO LUCK..... TOOK A MECHANIC HE SAID IT WAS OUT OF TIME AND THE MSD NEW COIL WAS BAD....... GOT NEW COI AND STARTED UP FIN.... DROVE AGAING FOR ABOUT 20 MINUTES THE SAME STORY IT SUDDENLY DIES AND NO START...... I CHECKED FUEL PRESSURE AND SPARK AND ITS ALL FINE.... CAR MAKES LITTLE EXPLOSIONS WHEN I TRY TO START BUT WONT FIRE UP.... ALREADY WASTED LIKE $2000 DOLLARS IN MECANICS,PARTS, AND TOW TRUCKS..... [PLEASE GUYS HELP ME I GOT NO MORE IDEAS

 

Test the ICM when it's hot it might be getting heat soaked. Have you scanned it for codes?

 

Probably that accel opti. I'd have went with a Delphi unit myself. I can't ever bring myself to trust msd or whoever else throws their hand into making an optispark. If the mechanic says its out of timing, and if he's correct, than that alone tells you its the opti, since the timing is computer controlled and is sent to the pcm by the opti itself.

Go with tried and true imo, get a gm/delphi unit.

 

Your timing chain didn't break did it?
And are you getting spark...Its not common for them to break but it is possible. And that would cause it to not be able to time itself correctly.

 

Yeah that is true. It'd be worth the effort to check your chain before buying a new opti. Even as uncommon as it is. Its worth a shot.

 

so in order to check the timing belt i would have to open up the cover right?...... also my mechanic got no codes...... another thing he was thinking was the maybe the vats system was activated.....

 

Yes you would have to tear the front half of your engine apart ... Its not really that bad once you have done it a few times...

 

think the vats system may have something to do?

 

If vats was active, the "SECURITY" light would be on.

 

Chain, not a belt is not likely to break. Not after having done ignition work, although the opti is driven from the cam shaft.

There are several ways to tell if the chain were broke with OUT removing the timing cover.

One is remove a valve cover and see if all the rockers are moving.

Another is crank it over and see if the oil pressure is coming up.

The best method is to remove the distributor cap and put a cylinder at top dead. Then see if the rotor is facing the direction of that cylinders contact point.

However, I have a better suggestion. Since all this started when you put the crappy parts on, why not put the originals back on????????? Nothing good has ever come from MSD or Accel for the LT1.

 

i did put the original part back on .. still same..... when car cranks oil pressure goes up////// also the security light stays on for a few seconds while cranking the car

 

I originally saw where you said you replaced both coil and distributor. Then you said this the original part. Do did you put the original distributor back on or not?

 

The "SECURITY" light should come on for a five seconds when you turn the key to "run", and then go out and stay off. From the Owner's Manual:

"If the engine does not start, and the SECURITY light stays on when you try to start the vehicle, the key may be dirty or wet."

Are you sure your mechanic used the correct scan tool - the 95 is confusing to many, because it has an OBD-I PCM and a 16-pin OBD-II style ALDL connector? There are several critical codes that affect starting but do not turn on the SES light.

 

okay guys i got a new update

..... i check all my optispoark wires to pcm and found everything perfect.... also checked my coil and i am getting spark and fuel... also check the vats system...... all good but car still just cranks and cranks but wont fire up... new icm again.... i am so lost.... what next?

 

Did you flood your spark plugs out trying to crank it over?
Take one of your plugs out if it smells like fuel u prob flooded it out. and might need to replace them...

Did you check all your grounds if one of your ground wires broke it won't start either...

Also there is a inline fuse located up by the battery is that blown that will keep it from starting.

when you scan your computer any codes?