Intermittent No Start Please Help Anyone!

[BradleyJ]

I was wondering if anyone could help me with a very, very, very frustrating problem I'm experiencing with my 93 Corvette.

Here is the problem:

My car occasionally will not start. During these intermittent no-start scenarios, it will fire up for a second then everything suddenly goes dead. If you take the key completely out of the ignition, replace it, and try again it will do exactly the same thing. (i.e. fire up for a brief moment, then suddenly shut down.) If you leave the car alone for a few hours, then come back and try again, it will start with no problem. NOTE: This problem ONLY occurs after the car has reached operating temperature and has then sat for a few hours. When it is cold in the morning, it ALWAYS starts with no problem.

When the car will start, it runs beautifully except for the following: Occasionally, on the center LED, where the speedometer displays, the characters "sys" flash three times about every 30 seconds. In the lower left hand corner of the dash, the amber light that says "Security" flashes at exactly the same time as the "sys" message. I don't know if this is related to the no-start problem.


Here are the stats for the car:

'93 coupe
automatic transmission
62,300 miles
fx3 suspension
brand new battery (problem was occurring before new battery)

This problem is incredibly frustrating because I can't find anyone who knows how to diagnose or fix this problem.

I used to love this car but it is quickly turning into a nightmare.

Any advice would be greatly appreciated.

Thanks

 

[BradleyJ]

Keith, thanks for the reply!

Yes, my car does have the VATS system, and I have heard that this system can be unreliable.

A problem in the VATS system seems reasonable but my local dealer assured me that if the VATS were malfunctioning, my car would not crank at all. (mine will actually start for a brief moment before it dies.)

I think there is some serious electrical problem somewhere that may or may not be related to the VATS system. I just can't imagine why it is so intermittent.

Thanks again,
Brad

 

[Ken]

I just can't imagine why it is so intermittent.

I feel for ya Brad, but when you get around to reading some of the other threads regarding this problem, you'll discover that I have been going through this for years now. :eyerole

Wish I could help.

_ken

 

[vigman]

Fuel

I think it's fuel pressure.....
Your car
Cranks
Fires
Dies
Can crank again
But no start or just sputters ( right?)

I would get a fuel pressure meter and look at the rails when you have the Crank but no start issue.

And I would verify that you have spark....

The Sys thing is a C4C5 Spec. question
Do you have access to a code scanner?

And When you have the no start thing.... do you hear the fuel pump wind up?


Mike

 

[vigman]

Hmmmmm

Not thinking the VATS key pellet (yet)

Because... if it cranks every time, the VATS thinks things are ok...


Need more info


( Trapped @ work )

Mike

 

[Topless]

Ok, I have been pondering this....I am leaning toward the fuel pump. Heat kills these things, and are known to do that intermitant thing before they die (been there, stalled that).

Of course this is Sunday, so time for a "hail mary"~ Vapor lock???? :eyerole

I am still betting on the fuel pump though.

Mike

 

[c4c5specialist]

Hi there,
You may have a stacked condition, as where you are experiencing codes from you ECM, and the CCM, causing your SYS light, and the security light to flash.
I would first check out for codes, and then proceed, as the problem may be in the codes.
Besttoyou, and please keep us posted, c4c5

 

[BradleyJ]

Thanks to everyone for the advice.

I think I finally found the problem. (whew!)

I took my car to a local mechanic (not a Chevrolet dealer but ASE certified) who knows a lot about GM electrical / computer systems. After running some kind of diagnostics, he determined that the ECM was fried. I'm not exactly sure what was wrong with it, but he said it needed to be repaced so I had him replace it with an original (rebuilt) GM unit.

Now, not only is the intermittent no-start problem solved but the car actually seems to run better (maybe it's my imagination).

Anyway, thanks again for your help.

 

[bjtaueg1]

93 Corvette Intermittent Starting

I have a '93 with 155k and it runs great! But recently encountered an intermittent starting issue. I started with my fuses and there are 2 fuel pump fuses and one of mine not only had the wrong fuse in but it was also blown. Long story short, my car now starts every time. Start with fuses and wiring before you get into the engine.

 

[tmkassin]

I have had this same problem with my 1992. It turned out to be a bad plug on the wire leading to the key reader under the dash. I solved this by cutting the plug off and hard wiring the key reader. There are a pair of wires coming out of the steering column with an orange housing. Disconnect your neg battery cable and cut out the plug. Then solder it back together and tape or shrink tube it. I have seen a lot of posts with this problem and never found anyone with this answer. It worked for me... let me know if it helps you.