curving_edge

I recently just bought a 1979 Chevy Corvette with 81k original miles and I am the 3rd owner. I am no expert mechanic but I know my way around if need be. I love the car to death but I am now clueless on what to do. Here is the problem.

Car ran great a-b no problem untill the car started to stumble on accel. As I was driving 45 mph with the pedal half way down to keep at 45, the vehicle suddenly started decelerating. As i pumped the pedal to accelerate, the car quickly decelerated faster until the engine actually died. So I pulled over in a neiborhood and tried cranking her, and nothing. gave her 5 min and she came to life like nothing happened. She kept doing this during the next week, dying 2-3 times a day! So I asked a couple of friends what the trouble could be since they are chevy-holics and gave me some pointers. 1)Replace the carb 2)vaccumm lines gotta go 3) EGR has gotta go

So I did, letting them do it since they have done this first hand to their nova's and charger's. I now have a Edelbrock 600 on. Edelbrock intake. Vaccumm lines astray. And a custom plate to cover the EGR.

Drove the car some more that following day and she seemed to be more attentive. But died even more! So I asked a technician and he gave some following pointers. 1)Fuel filter 2)Fuel lines leaking 3) Fuel Pump.

I changed fuel filters (Good thing, they were black). I checked all fuel lines and replaced all (Good thing, one was leakin). and replaced the fuel pump from Advance Auto (Factory Replacement).

Drove the car for a full two days without a Acceleration Stumble/Die problem. Then what do you know? It happens again, but this time its less abundant. But this time, any time I put the car under full load/acceleration, it dies. I can drive the car city wise, but on highway, it doesn't even perform.

So I asked the mechanic again what could be happeneing, and he said most of the time when fuel delivery (dunno even if its fuel delivery problems yet) that there is a 'sock' in the gas tank and could be getting clogged. And i need to hook up a compressor to the fuel line going to the tank bipassing the fuel pump and blow it out.

So I did that too.

The damn car still stumbles and dies just the same. I have now been told to switch out fuel tanks because mine could be dirty but I DO NOT want to put the labor in it when I dont know if that could be the definite problem! That's dropping the rear-end!

So do you guys have any ideas? Have you had this happen to you? What was your rememdy? Also, i have been thinking that it might be the modual in the distributor? I have no idea. Could be missing vaccumm lines too. Im counting on expierence now. Thank You in advance for trying to help.

noonie

Since your repairs made it last for 2 days, I would still go with the fuel problem.

This assumes you didn't change the hard lines.
Get yourself about 5 feet of cheap 3/8 rubber fuel line.
take the line off before the fuel pump and put the 5 footer on there. Have a couple gas cans ready and a pair of vice grips to pinch off the rubber line. Blow into it to start the syphon action and you should be able to get a pretty good full stream into the gas cans.
If not, you have a blockage back to the tank.
Take off the gas cap and try again. If there is a difference then your tank is not venting properly.

Over the life of almost 30 years, the tank sock is the most likely culprit, if it is plugged and you don't want to take the tank off now you can blow high psi air back thru the line with the gas cap off. This will likely blow a hole in the sock or blow it off. If you do this, then drain gas into a container to flush and check for crud. Be aware that this could also lessen the life of your fuel pump and cause you to change filters much more often. Buy you some time anyway.

Your new filter now may be plugged already. Check it.

Once you eliminate fuel feed to the pump, you can go from there.

Stewart's74

I'd take a look at your coil and distributor. As Lars says, 90% of "Carb" related issues usually turn out to be the ignition.

Stu

tsker79

For what it's worth, if you have a high mileage car with the cat. converter still on, you may have a bad converter. As they get high miles on them, they have a tendency to plug up and stall out the car. I wouldn't immediately go out and replace it, but possibly you could have it checked out or remove it and run with a "test pipe" to see if it runs or not. Just my $.02.

curving_edge

thank you for the replys, it is helping alot. You have no idea. And the guy before me had the exhaust done, no more cats!

well i had a suggestion on taking off the Vacuum advance line and run the vehicle. To see if it will die on me. Well I drove the car for 3-4 straight hours with no problem, even on highway! then at about 1am it died. On the highway... I stumbled it back. What that tells me is that the distributer/plugs/wires/and vacuum advance needs replaced right? thats my next step...

what brand is optimum for my 350? should i just go to the parts store for factory replacements? or should i go msd? I just hope to god, that ignition/timing is my issue...

What do you guys think?

Kneel 8250

I have had a similar problem with my daily driver (Toyota Corolla) and finished up replacing the ignition module which fixed the problem. The car has run without a problem now for around 4 years. Might be worth trying that if you have electronic ignition in your distributor.
Have a great day.

Ganey

Fuel- Check for kinked supply hose to fuel pump.

Ignition
Check the pickup coil for continuity. That system is considered to be very reliable. Many say the pickup coils do not fail. The movement of the vac. advance can cause the leads to break internally- may not be noticeable looking at them. Move the vac. advance while checking.
Typical HEI pickup coil ohms about 800.
It's possible to disassemble the pickup coil & repair the leads.

Ignition Module - if 10+ years old, would be best to replace even if good. AutoZone has Wells (OEM supplier).

curving_edge

sorry i posted this more than once. it'll continue in the tech and performace area.



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