Starting problem with my yellow 93

[Jim Martley]

Monday morning I went to drive the car to work and it would just crank over and not run. When I came home from work in the afternoon I tried it again with the same results. I checked the ECM & the CCM for codes and got none. I checked for fuel pressure and it was at 40psi. I checked for spark at the coil and had plenty. I checked for injector pulse and tha was fine. I started to notice that the engine would try to run backward if I didn't turn the key to the off position after cranking it a few times. Out of desperation I condemed the optispark and ordered a new MSD unit from Summit Racing. It came in yesterday and I installed it. I test fired the car after installing just the new opti and it started right up

! I proceded to struggle putting the rest of the stuff back on the front of the engine and filled the cooling system. I went to start it up and now it is acting like it did before

. I checked to see if I pinched a wire or something stupid like that and found no reason for the change.

The engine acts like the timing is severly retarded. I also don't hear the "spark knock" sound that I usually hear when a LT1 is cranking over.

Anybody have any suggestions?

 

[Jim Martley]

UPDATE!!!!!!

Last Friday I came home and started to go thru the check out procedure in the service manual for a "crank but no start condition". Half way thru the procedure the damn car started right up!!!!!
Not being the type who trusts a "self-healing" car problem I spent the rest of the weekend starting the car EVERY chance I got. I must have started it 50 times and it ran beautiful.

I still wasn't brave enough to dive it though.

Yesterday (Monday) afternoon I noticed the brakes on my pick up truck were starting to make a grinding sound so I pulled it apart and sure enough the inboard pads were shot and it took out one rotor. I had test run the 93 earlier and decided to run to the parts store with it. YUP!!! It died in the parking lot of the parts store

. I had it flatbedded home and I put it in the garage and closed the door

.

Tonight I had a friend of mine and a buddy of his that is a GM Tech come over with his "Tech-1" scanner and we went thru the diagonastics on the car together. NOTHING showed up again. I still was getting spark from the coil, a pulse for the injectors and PLENTY of fuel pressure.
The Tech said that sometimes he just HAS to try swapping parts to figure out what is wrong. Luckly my wife's car was sitting in the garage and she was gone for the evening so we started to try on some parts. The first was the spark control module. No change. Next was the ECM. No change, THANK HEAVENS!!! Last but not least was the Ign. Coil/Module assm. BINGO!!!!!!!! The car started right up. I tried my old one on her 93 and all I get was crank, crank, crank. I ordered a new module and coil from Napa and it will be in tomorrow afternoon.

The GM Tech is building a Cobra Kit Car with a stroked small block Chevy in it so I know I will have a chance to help him out in the future to return the favor.

 

[MoeJr]

Cool. Glad you got it running. How many Vettes do you have?

 

[GS Diva]

Cool. Glad you got it running. How many Vettes do you have?

He has three!! And all gorgeous....my favorite is Jim's '82 red coupe!!

And, Jim, I'm glad you solved the mystery.

Elaine

 

[LT4man]

Congrats on getting your Vette to run!

Do you think the Opti was bad? Even so, nice to have that good lookin' MSD unit on there!

The ignition module and ignition coil really do not fail too often. Their symptoms are very similar to bad Optis. Hard one to diagnose. Nice that your buddy could help you.

SAVE THE WAVE!

 

[Jim Martley]

At this point I don't believe the Opti was bad BUT I sure as hell am not going to rip the car apart to put my old one on to try it. Even I am not that much of a glutton for punishment :L !! Like you said, at least I have a shiney new billit aluminum Opti with a sexy red cap on it. The other plus is that the MSD unit has a venting system simular to the later model opti's and MAYBE it will last for the rest of my ownership of the car. Too bad you can't even see the damn thing.

 

[LT4man]

Good points!

I had forgotten yours was a 93. The 1st design. The MSD unit is a beautiful unit. I was not aware they had venting. Good deal!

You are right about the darn thing being buried at the bottom.

That was always the intent of the GM & Mitsubishi engineers. They wanted a low profile hood so the only place to mount the distributor was on the timing cover. The Opti was designed to last 100,00+ miles. Too bad the early non-vented ones did not do so well.

SAVE THE WAVE!