92 stroker, MSD 6a box,

Problem: Motor turns over, it just doesn't start running. It does this if it sits for awhile (24 hours) until one day it will just start right up.

Things I've checked...

1. Fuel pressure doesn't leak down (injectors, pump), FPR is not wet.
2. No wet plugs
3. Spark plugs = New
4. Spark Wires = New
5. Good spark from coil to opti
6. Good spark from opti to plugs
7. Took the battery to autozone, it's good
8. Nothing blocking air into intake
9. Fuses good (This is an intermediate thing so i knew before i checked they were good)
10. No codes. (Just the 12 code)
11. Noid light blinks on injectors
12. New CTS
13. I have no MAF sensor
14. Emissions removed

Of note...

1. Sometimes if i try working the gas pedal when I'm trying to start it, and it doesn't start, i will get some blue smoke coming out of the intake.

2. The wife is about to cut my ***** off if i don't get this thing running right.

3. SOMETIMES when i turn the key during a no-start session, the act of turning the key has a little bit of resistance, not like it's catching on something, just kinda like the resistance you feel when you kick something at the bottom of a pool. It's only like that SOMETIMES. I don't think it has anything to do with it though.

 

Have you put a noid light on an injector yet?

 

Yes, sorry i forgot to list that

 

Nevermind, I just saw your edit.

 

Have you checked around/swapped the ECM? Have you checked all engine/ECM grounds? It would be nice if you could borrow a 92-93 ECM to try out. These year ECM's are difficult to find, so I hear.

Sorry, I need to go back and read the other thread, this may have been covered already.

 

That would have been my guess too, except I can't think of anything the ECM could affect that he hasn't checked during the no-start condition.

 

I really can't either. After reading the previous threads it sounds like a ground problem somewhere. That or a bad circuit (wire) connection or a grounded circuit (wire).

Seemed that with a full charged battery and wiggling the bat connections, the engine fired up out of no where. Not sure, where all the engine grounds are on the 92.

Just another suggestion, if it hasn't been tried. It won't cost any money to check the grounds, just some time.

 

I dunno, this is a mystery. All the grounds on the 92 are on a bolt on the driver's side of the block, right around the middle bell housing/AT bolt. But if he had a bad ground, it doesn't stop the injectors firing and spark at the plugs. And he has fuel pressure and air.

 

Check spark timing while cranking. Pull a plug wire and bring a grounded test wire near the plug wire while someone cranks, spark should be over 1/2" long. Unplug MAF and try a start. Measure and record compression on every cylinder.

 

I've been having the same trouble as you describe and have checked everything as you did and can't find the source either. But mine will crank fine somedays and probably tomorrow it'll crank then try to die but it'll drive. After dealing with this over a month now I believe it's time to go see the man.

 

1. I'll have to get with someone that knows how to check timing, never had to mess with that before.

2. I have a spark tester and the spark is over 1/2" long.

3. No MAF

4. I'll have to get with sometime to do that also.

Someone mentioned trying a spare ECM. Wish i had one

 

Your timing isn't adjustable. If you did crank the opti down wrong on the cam, it would be hosed all the time, not intermittant. Same goes with compression and anything else I can think of in the engine internals.

You could check with VetteUSA and see when he will be done with my spare 92/93 ECM.

 

Swap your ignition relay with the cooling fan relay that is identical, and check the relay contacts.

 

Did you actually test what the fuel pressure is? It should be around 45psi at least.

I went thru a no run condition with my yellow 93 this past summer and even though I had what I thought was good spark, it turned out that my Ignition module/coil was bad.

 

Where is the ignition relay?

 

EGR valve MUST be seated or starting will be difficult or impossible.

 

I know exactly what you mean, I had a cavalier that did that all the freakin time. Annoying, but that car always started- I don't think this is related to your problem. I think this is just a worn out ignition.


I agree with JFB's EGR comment. If the valve isn't seating right, it'd be hard to start the car... give it a day or so- enough time for the valve to seat- and it'll be fine....

That is assuming your FP leakdown numbers are good... what did you say they were?

 

Fuel pressure numbers:

Primed with line on

10:09 = 43PSI Line On
10:19 = 43PSI Line On
10:29 = 43PSI Line On

Released pressure, took line off FPR, primed again

10:30 = 44PSI Line Off
10:40 = 44PSI Line Off

Released pressure, put line back on FPR, primed again

While Cranking = 44PSI for 2 seconds, 35PSI for 1 second, 44PSI for 2 seconds, repeat

 

On my '93 the ignition relay is up behind the carpeted bolster in the dash. Right about where your left knee would be. I believe it was the middle relay.

Just an idea here for others to poke holes in, but is it possible for the CCM (VATS) to disable fuel delivery but not the starter?