1993 Camaro LT1 wont crank after reaches running temperature.

[tonys02slpss]

My 93 camaro z28 m6 started messing up Wednesday. I was driving home and it jerked twice while driving then I pulled in the driveway to check the mail and it almost died but jumped back up. When out 2hrs later and it would just turn but not crank. Took my truck came back 3hrs later and it cranked right up. It cranks right up when cold but after it warms to its temperature and I cut it off it cont crank anymore just turns. It has to be cooled down to turn on again. I had the opti replaced with a summit brand one and got a GM ICM 6months ago. I went to text the GM ICM today and they test it 3 times and it passed but I still bought a new Auto zone one and put it on and still does the same? Does anyone have any suggestions what it may be now?

[steveo]

your terminology is a bit confusing 'cranking' is when the starter works to turn the engine over. its a leftover term from when cars actually had a crank handle on the front to start them.

what you describe is usually ICM problems. did you put thermal paste on the new ICM when you installed it? was there thermal paste when you took the old ICM off?

could be that nice shiny new 'summit opti' too. those are a real peice of shit.

you should scan it for codes before going any further

[steveo]

coils can fail like that too (start working again when they cool off), so can fuel pumps, just fyi, and both are really really easy to check if you can make it die again.

[tonys02slpss]

Originally Posted by steveo

your terminology is a bit confusing 'cranking' is when the starter works to turn the engine over. its a leftover term from when cars actually had a crank handle on the front to start them.

what you describe is usually ICM problems. did you put thermal paste on the new ICM when you installed it? was there thermal paste when you took the old ICM off?

could be that nice shiny new 'summit opti' too. those are a real peice of shit.

you should scan it for codes before going any further

Well it tries to start but it just won't fire up that's what I mean. And yes the gm icm had the white grease and I put some on the new one . The engine light is jot on though could I still get codes?

[tonys02slpss]

Originally Posted by steveo

coils can fail like that too (start working again when they cool off), so can fuel pumps, just fyi, and both are really really easy to check if you can make it die again.

How can I check the fuel pump you mean by checking up front see if it has fuel pressure? And how can I check the coil? Sorry if I don't know much I was away from fbodies for a while had a 94z28 then 02 ss and now this one.

[Workman]

Could be MAF? My corvette did the same thing when its MAF was bad. It would start, get to operating temp then boop! done -.- cool off, start again then get warm and boop -.- done lol, But if i put it in drive, it would stagger and cut off lol Replaced the MAF and she fired and ran for the next 6 months until i sold her =]

p.s. she still runs to this day

[Workman]

If you can, just grab a MAF to see if thats a prob. Here we have a triple A salvage palce that test all the parts off wrecked cars and if they are good, yu can get them for really cheap prices i dont have any junk parts on my car but you should just grab a MAF to see if thats the problem.

[steveo]

his car doesn't have a maf... it's a '93

p.s. unplugging your maf altogether would have diagnosed that problem,

[95 Firehawk]

Originally Posted by tonys02slpss

The engine light is jot on though could I still get codes?

The codes DTC 16 and 36 are both major opti failures that won't light the check engine light. DTC 16 (no low resolution pulse), if active, will disable the fuel pump and injectors while a DTC 36 (no high resolution pulse) will cause hard starting and rough running.

First thing is to scan for codes and verify fuel pressure and spark.

[philosophico]

Its either fuel or spark. You tested another ICM and it is still doing the same thing, the next thing to check would be your fuel pressure.

Since you have a 93 like me, check your fuel pressure regulator. Pull off the little hose on the tip and feel for gas. If it is wet, your regulator is shot and needs to be replaced.

You might want to also check your ignition coil.

[tonys02slpss]

Originally Posted by philosophico

Its either fuel or spark. You tested another ICM and it is still doing the same thing, the next thing to check would be your fuel pressure.

Since you have a 93 like me, check your fuel pressure regulator. Pull off the little hose on the tip and feel for gas. If it is wet, your regulator is shot and needs to be replaced.

You might want to also check your ignition coil.

Yea I got a new one from auto zone yesterday for $118 and it was the same so I put the old one back on and returned the new one. This morning I went out and cranked right up but it stayed on for 1min and then it cut off and wouldnt crank anymore. I unplugged the icm and the battery for a couple of minutes and nothing. I checked the furl pressure at the front when you take the small cap off on the block and it squirted so the fuel pump is working. Then 2minutes later it cranked right up and I let it warm up and ran it on the road and runs fine it dont pull or nothing. Then turn it off and turned right on did it about 3 times. Then went back out 10 minutes later and it doesnt start just turns but never cranks.

[tonys02slpss]

Anyone have any other idea what it might be?

[Workman]

If he has an LT1 I really wouldve thought he had a MAF? my B lol

[Workman]

When you first start it up what really happens? Does it pop? Does it just cut out ?

[tonys02slpss]

Originally Posted by Workman

Do you have to keep your foot on the throttle to keep it on when you do?

I can go out there right now and it will crank right up with no problem dont have to give it gas or anything. Sometimes it will just cut off and not turn back on till later but most time it will stay on and idle normal and I can drive it and it wont miss or jerk but once I turn it off it wont crank back it just turns like trying to crank. No popping or anything...