JiminSTLouis

I was going for a joy ride today and my Vette suddenly started to sputter, I got no power and it died. It did this 3 times back to back. The first 2 times it started up again after about 10 seconds of cranking, but struggled to get power. The 3rd time took several minutes to fire up again, but when it did it ran perfectly the rest of the way home, about 20 minutes. I was driving maybe 30-40 minutes before the issue started. It seemed like a fuel issue, not a spark issue. I didn’t smell fuel while driving or after I got home and opened the hood. The air filter had a slight smell of fuel but that’s probably normal with the environment it lives in. Tomorrow I’m going to start with the easiest thing and check the fuel filter.

Are there any similar experiences? This is the first time this has happened in the 2 years I’ve had it.

Additional info:
L48
Previous owner put in a new fuel tank and sending unit
I replaced the fuel pump (mechanical) when I bought the car
I only ever put premium gas in it
As far as I know it has all original fuel lines
30,000 original miles

Thanks

HeadsU.P.

Go to Harbor Freight. Buy a sparkplug test light ($6). Every C3 owner should have one behind the seat.
Pull any plug wire out of the dizzy cap. Install the tester in that spot.
Crank it. Any firing?

Could be modge. Could be coil. Both get hot, shut-down, but will restart.

4-vettes

I too think it would be spark. Not fuel.
A module comes to mind first. A ign. coil, of which I have had 2 fail. In different ways I might add. Would also be my second thought.
The grade of fuel your running or how new the tank is wouldn't even be on the radar.

DWAVette

Not that my opinion is worth anything, but I think 4-Vettes is right. Really sounds like the module is overheating in that HEI and going haywire.
They can be tested by some auto parts stores and they are pretty easy to change.
Low hanging fruit before moving on to something else.

klturi421

If it sputters then dies then I would say it's a fuel issue. If it just cuts out instantly then spark. I was able to somewhat test this as I have an electronic fuel pump by disconnecting the power to the fuel pump as it was running and observed how the engine responded. That was the only time I ever got it to sputter.

I had a similar issue a few months ago. I could drive for varied lengths of time and some days it was just fine and others it would die out after a short drive. I ended up replacing the Ignition Coil, Pick Up magnet, and Ignition Control Module (ICM), all with AC Delco parts. At one point I tried using a MasterPro and then Standard ICM and both seemed to run about the same and would still stall after 15-20 minutes of driving. I ended up finding an ACDelco ICM, put it in, and haven't had issues since. I also recommend getting good thermal paste if you do swap the ICM. I used Noctua HT-1. Be sure to coat the ICM and the plate the ICM sits on for best results. One thing to keep in mind is my dizzy is stock Delco Remy and I needed to use AC Delco parts. If yours is not stock then you may be okay with getting another brand ICM. Just my experience with it.

JiminSTLouis

UPDATE:

The Corvette is done.

Changed:
Distributor cap and rotor
Ignition module
Ignition coil
Fuel filter

After changing those components, the car still lost power and stalled. Checked the fuel pump next and it appears something internal broke and was rattling around. Changed that and the car now runs perfectly. Also, the new fuel filter has a check valve on it to keep the line behind the filter from draining backwards. The engine fires up immediately upon hitting the ignition. It’s always cranked for a few seconds before.

I’m ready for my road trip.

Thanks for all the advice.

4-vettes

Whoo Hooo! Glad ya got her fixed. Sorry ya didn't find the pump first. But sometimes that's just the way it goes. You do all the easy, obvious stuff first. Then ya either fixed it or ya find it.
At least she's fixed!

JiminSTLouis

Thanks @4-vettes . I don’t mind having all new ignition components. An extra sense of security on the road.