dear all

thanks for your help re the temperatures and cig fuse - hoped I could run another one by you. I doubt I have driven the car a dozen times to date - in the last 3 times out I have experienced something unusual within the first 20 minutes of driving - this is:

Car starts OK (everytime) and after a 4-5 minute warm-up I hit the road. Then over the next 5-15 minutes I feel/see the throttle struggle and the rpm's idle very close to stalling ...... and then it stalls.

Luckily I have a good battery because it take 30-60 seconds of trying to re-start (5-10 second cranks) then you hear/feel it catching and give a bit of gas and she fires back up (with blackish looking smoke coming out the back for a second or 2 - then clears up) The exhaust fumes appear clear all the time except when this happens. This stall-out usually happens a couple of times in the first 20 minutes - then (when warmed up)all runs well.

This all started occurring after I had and remedied a radiator hose leak (all seems OK on that front) Any ideas as to what I am dealing with here (and hopefully how to deal with it is greatly appreciated as I am 100+ miles from any garage whom know Corvettes - cheers!)

Thanks again everyone for all your help

Is it throwing any codes?

Matthew

Dear Matalk

The ECM was replaced 2 months ago with a new Unit and Chip sent here from a Canadian GM Parts Dealer. I assume all went ok and when I picked up the car I was told that it was not giving out any codes (mind you it did not suffer stalls like this then either)

I must admin I have seen bits and peices on how to paperclip a plug so the dash display will display any error codes but I have yet to do this (having 2 c4's I really should get my head around this - not to mention there are no GM dealers on every other corener here in the UK - so hands on I must be)

I will endeavor this in the morning and hope to get the car to a shop whom knows C4's this weekend to look over this matter and a few others as well as soon as they can.

really appreciate your time

It sounds like the typical symptoms of an optispark failure.
Did the radiator hose leak on the front of the engine?

Quote:

Pull the codes yourself first. All you need is a paperclip.

Check out this site:

(see Andy's post below)

Matthew

you need this one:

http://www.corvette-guru.com/uploads/ ... section/3_CCMCodePull.pdf

Thanks Andy, I couldn't find it for some reason.

Matthew

It's in the tech library... I hope it helps!

Quote:

Dear 95vette

Possibly - it was a narrow rad-hose that runs from the front of the engine compartment over and into the top of the engine. The hose did not split in 2 but rather on the clamp that holds the hose (on top of the engine) had cut into the hose and so it was spraying fluid mainly onto the top of the clam shell in the form of a spray.

So as to answer your question - I was driving the car for 2 hours when this happened (not sure when it did occur) but the leak was isolated and repaired shortly after arrival). Because the hose that cracked was above the engine I do believe some of the rad fluid hit and ran down from the top of the engine.

If it is the Opti-Spark:

Are they pricey to replace?

Can they be repaired?

As it only seems to cut this way in the first 20 minutes - if I was sure I was past this point - do you believe I would be OK to drive the car to the repair Center (2 hours away) or do you think the car being warmed up has nothing to do with when it will cut out and I could end up stranded?

thanks everyone - sure appreciate you time

Quote:

CHEERS Bogus - this is a Huge help (as you always are) - spot on!

Quote:

If it is the opti (we haven't narrowed it down for sure yet) yes it is expensive to have a shop replace it. Over here expect around $1000 because of labor costs. There are a lot of pieces that need to come off before you can replace it. Most people go ahead and replace the water pump at the same time as preventive maintenance. You can save yourself a lot of money if you can do it yourself, plus the pride of knowing you worked on your own car.

I don't know in the UK how prices are for GM parts, over here it costs about $400 for a stock one, a little less for cheaper aftermarket, and around $500 for an MSD aftermarket. Some people love the MSD, some people have had them fail almost immediately.

I recommend you pull the codes just to make sure, but it sounds like if you had that much coolant spraying on the unit it could have caused a failure.

Matthew

Dear Mathew

Thanks pal - your advice (if it is the opti-spark) is much appreciated as is your common sense suggestion to swap out the water pump at the same time. I am dropping the car off tomorrow and the guys at Clairemont Corvette can baby her back to good health next week. I would like to pull the codes first though - I will have a crack tomorrow morning

take care and have a great weekend

If it was the opti failing that seriously, I would expect a bunch of codes.