I am having an issue with my 1999 Corvette Coupe (manual transmission) that may be electrical and I wanted to see if my description of the symptoms might ring a bell with someone. I will try to make this short as I appreciate everyone is busy.

My engine is an old block with rebuilt insides. Last year the car started to run rough and die when I would leave the beltway and pull up to a stop light or just even a stop sign.

My mechanic did a lot of diagnosis and at first only found some loose and corroded grounds on the chassis which did not fix the issue when he addressed them.

Eventually he replaced the PCM with a new computer and that seemed to fix the issue, until. After about 2000 miles:

Just recently the car started to die at high speed. I mean I could be going 60mph and suddenly the car would be dead, as if I tuned it off with a key.

The first couple times this happened, somehow the car sprung back to life as if I was kick starting it if I had a dead battery.

More recently, the car is dying at high speed and, while it has started again, it is hard to restart. I tried six time to start it this past time and while it was turning over it was not catching or starting. Eventually it did start and I was able to go an additional 15 miles to my destination (this is after driving 85 of my 100 mile trek).

The next day I was able to start the car (although it does not fire up as quickly as it has in the past with what I’ll call normally) and drive the 100 mile home without issue.

As I really have no clue as to what to try next or have my mechanic try I am hoping these details may provide enough detail where someone might have an idea or two.

Thanks for any help with diagnosing this

Chuck Schramm

 

When it won't start, what is your mechanic's scan tool showing is the problem?

After it dies, what codes are present (either historical or current)?

 

Could be fuel filter, injectors. Do you have a fuel pressure gauge? Connect it while running and see if it holds after turning the car off. If fuel is draining back to the tank it would be a hard start condition. As Dads said, are there any errors in the DIC?

 

It doesn't have this issue in the presence of the mechanic as it happens when I am driving on the highway.

The only codes C or H are related to not having tire pressure sensors or mass air flow

 

I thought of fuel pump issue or maybe filter.

Will have mechanic check out your suggestion. The car has always started again so far even if it takes several tries.

No codes other than tire pressure sensor and mass air flow history codes

 

It sure sounds similar to several threads over time related to a less than ideal ignition switch. If your mechanic has already done a bit of shotgun diagnosis, a new switch is $100 or so at Rock. There are a couple of youtubes out there on it, of course.

 

I am one of those who posted about my summer long electrical issues. The solution to my problem was an ignition switch replacement. It's not that hard to do if you work on the car yourself. There are videos on youtube to show how to complete this job. Your issues are all too familiar to me. I would try replacing your ignition switch before tearing your hair out like I did.

 

While cranking the engine over see if the Tach moves…if NOT it may be a bad crank sensor…no spark or injector pulse with bad sensor !!…have your mechanic check to see if you are getting both…if sensor he should check the wiring to the sensor if he knows how…most mechanics only know how to change parts…less than 25% of PCM’s are actually bad.