Lee_533

Hey guys. I have a 92 with the LT1. It was having trouble starting and for the life of me I can't figure it out. Sometimes it would start then die. Other times you can crank and crank and get nothing. It happens at random (cold or hot). Once it's going it runs fine but does have a slight miss around 2K RPMs but doesn't try to die or anything. I changed the fuel filter and fuel pump and it ran good for 3 days with no sign of starting problems. Then today, it started acting up again. I started it and it died right away. Primed the fuel pump a few times then tried and nothing, finally it just started. Drove to the store for some parts then had trouble starting again. I have looked all over the forums trying to find out what the problem is but it doesn't seem like anyone else has this problem. I checked the connections going to the computer and everything's tight. The ignition is about 2 years old. Now, I did notice today that sometimes when I went to prime the engine, the fuel pump wouldn't kick. Fuel Pump Relay maybe? But if it was the relay, why wouldn't it die while I was driving? If anyone has any info on this thing please throw your ideas at me, I am getting desperate and running out of money Oh, and from time to time my check engine light will come on but only after I've been driving it a while (30 to 40 miles) and my security light flashes from time to time and every 30 seconds to a minute the digital dash will flash SYS at me. But the car is running good and passes smog with flying colors! I'm about to go crazy and thinking of giving up on this car. So Please Help. Thanks in advanced.

desertmike1

This could be any number of problems..

Your very first step should be to recover any stored Codes.

http://www.corvettebuyers.com/c4vettes/codes.htm

Lee_533

I would get the codes but I don't have an obd1 tester. But even if I got the code, it wouldn't explain the starting issue would it? The if the light kicks on, I can turn the car off and back on and the code goes away. I've read that the ECM can be going out? What's the possibility of a bad ECM or chip? That would put a "ghost" in the system right?

desertmike1

You don't need an OBDI tester to recover codes. Did you go to the Hyperlink I gave you..

Let's say it comes up with an i.e. DTC36 this could indicat the ECM is sensing a problem with the ignition system. (Example)

Any time there is an issue the first step should be Code retrieval..

here is another good site as well.

http://tech.corvettecentral.com/2011...trouble-codes/

Cliff Harris

Check your wiring around the optispark and ignition module. It is quite common to have a bad connection inside one of the connectors in that area.

Lee_533

Well if it was a bad connection, wouldn't it try to die while driving it? I mean if spark cut out while driving, wouldn't the car die? Or is the optispark just for starting purposes?

jaa1992

Maybe - maybe not

My 92 would run fantastic till it got to 230*
Then it sometimes wouldn't go over 3000 RPM without bogging down
Then it would stall sometimes
Stall when hot = no start until it cooled down

So I threw an opti, coil, ICM at it
Same doggone thing
Had to go to a later opti with a new motor meant I had to change the connector on the passenger side.

La freakin da - no issues since

So yes - CHECK ALL THE FLIPPING CONNECTORS

Lee_533

Haha. Ok, that will be my project when I get home. I'll pull all the connectors and make sure they are all clean.
I'll let you know what happens

Lee_533

Ok...It's been a while since I've posted anything. I'm still having issues with starting when the engine is warm. All the same symptoms. I read that the ECM could possibly be bad? But then again the check engine light is not on. I did however disconnect the ECM last time I was having trouble starting it and as soon as I reconnected it the car fired up. When it does start up the engine idles pretty high for a while even when it's warm and takes some cranking to get the engine started. So what do you guys think? ECM? Old Batter? (battery is about 7 Years Old), or Opti spark?

ch@0s

Looking at this thread it looks like you didn't take anyone's suggestions seriously. Did you pull codes test spark or fuel pressure?

DUB

Just fixed one....with the EXACT SAME ISSUE!!!!!! It is a communication loss. The CCM (Central Control Module is not communicating with the ECM).

The CCM is trying to tell the ECM to enable FUEL...and when the SYS and SECURITY LIGHT both are flashing....it is dealing with circuit 800.

I sent the ECM out for PROFESSIONAL rebuilding. After preforming the complete diagnostics on it and even calling and talking with Gordon Kildebrew...who gave me more specific information...because it was NOT in the service manual.

Once I installed teh rebuilt ECM... the car has not failed ONCE.

AS for your miss. Depending on what parts you used when you replaced your ignition...they can be coming back to haunt you....if you bought cheap "stuff".

IF you check the codes in your CCM...they will direct you to the problem code and how and what to check. AND TRUST ME...if you attempt to remove the CCM...THIS IS NO PICNIC...even for me who does Corvette repair for a living.

I BET YOU...that when you just turn your key on....and the SYS and SECURITY lights DO NOT FLASH...I bet you would have fuel pressure...and the car will crank. IF these two lights are flashing...you are WASTING YOUR TIME trying to start the engine...save your battery....because it WILL NOT START!!!

IF you do not go into and check your cods in your CCM...which can be manually accessed without a scanner. You will NOT get this fixed. FREE ADVICE!!!! USE IT!!!

DUB

Lee_533

Ch@os: I have been doing everything people tell me to do. But it's a little hard to check codes manually when driving or when I get to work because the check engine light doesn't always come on and when it does it takes about 40 miles to do so.

Dub: thank you, I figured it was probably an ECM issue but wanted to confirm it before dropping money on one. Do you know here I can get one for a reasonable price? I would rather not send mine in because I drive the car every day. I only sometimes have problems when it's hot. Starts every time in the mornings or when the car isn't warmed up even if the sys and security lights on it will usually start. It's just a pain when it decides not to. And when it doesn't start, i can let it sit for about 10 minutes and it usually starts up then.

vetteoz

Any codes generated are stored until you clear them so you can pull them anytime.

If you have a DTC 41 common with the 92/93 cars then it can be any number of problems , not the ECM itself .
Many have lost their hair trying to narrow down the cause of a 41 code

http://forums.corvetteforum.com/c4-s...cm-or-ccm.html

DTC 41 tests
http://www.digitalcorvettes.com/foru...5&postcount=17

http://www.mainstreamtopics.com/foru...rt-diagnostic/

DUB

Lee 533,
I would send out the ECM to K & B SPECIALTY PRODUCTS at (770) 777-1031. Talk to "KEN" if you can. GREAT GUY!! It does not cost that much to get the ECM overhauled. Which is what I would do instead of getting a used or some aftermarket computer (which are usually crap anyway...from what I have experienced).

There is a chance that it can be in the CCM...which K & B can also overhaul/repair. This is why it is important that you check out the trouble code in the CCM. UNLESS you just want to guess at it and take the chance. When I performed the diagnostics on the trouble code in the CCM...it was kinda inconclusive. SO>>>I called and talked to Gordon Kildebrew and we talked (along with talking to KEN at K & B) and it was determined that there was a 85+% chance the problem was in the ECM...so I sent it to K & B and no problems with the car since the rebuilt ECM was installed.

You NEED to access your CCM and read the codes and verify that is it a communication loss code. Which is why it does it HOT or COLD engine.

Also..your security light should flash when you open the door...it is supposed to. BUT...when the door is shut and you turn your key...and the security light AND the SYS in the LCD dash area are flashing together...the engine will not start. It will turn over...but no fuel...which can also be verified with a fuel pressure gauge connected to the fuel test port on the right injector rail.

Removing the CCM is no picnic...lie I had previously mentioned...and re-installing ti is not party either. But I HAD TO DO IT...so I knew that I was not dealing with a bad/broken wire.

DUB

DUB

Lee 533,
DO NOT check your codes while driving.

When checking the CCM...the engine should NOT be running.

DUB

Joseph Schrum

Hi I have a 87 c4 that would shutoff anytime hot or cold where after shutting it down. Sometimes wouldn't start for hrs or minutes after shutting it off. After about one yr of this happening at least 3 times a week a Girl at a auto supply told me to wrap the starter with insulation wrap and the car never got hot but i thought that would be a bogas to do but i tried everything else. Well i did it over two yrs ago and it always started after shutting it off. Who would have thought of something like that. If anyone has a problem with starting after shut down where there's not even a ckick just do it and you will be a Happy camper. I dont know how the insulated on the outside of my started fixed my problem but it did.

Tact

Please start a new thread.