Car Dies – Diagnosis Appreciated

[xracerbob]

It sure sounds like a fuel/heat realted issue to me. When you are cruising along, the fuel is moving through the lines quick enough so it doesn't have a chance to heat up or boil. I would try and isolate the fuel line from any possible heat source.

The only other possibility I can think of is some debris in the carb bowl that once you decellerate or lift off the gas it blocks the fuel from leaving the carb.

[Blittleton]

CoERA,

I think Computworks is onto something. I have had the same thing happen to me and it was the Holley electrical fuel pump. There is a long history with these pumps from Holley. I would change the pump if you have electrical Holley and switch to a carter or walbro. The walbro is so quiet that you have to bend over at the rear wheel area just to hear it.

Bill

[CobERA]

Ron - It is a mechanical fuel pump.

Bob - I was thinking it was a heat/fuel ine problem too, but I'm not sure why it would crop up after 18,000 miles. I did partially wrap the line for the trip home, but it still died. I only did the part of the line the runs above the intake manifold, but not the part the runs down in front of the engine. I'll try to do a better, more complete insultation job. Also, I'll check the float bowl for debris.

Thanks,

[trularin]

I had a similar problem a couple of years ago, turned out to be the fuel pump was cutting out.

The way to find it was to put a fuel pressure Gage in line and read it in the car as I drove. I saw the pressure suddenly dropped to less than 2 PSI and the car died.

A quick way to check for a fuel problem is a can of starting fluid. If it dies and you can get it to run off the starting fuel, then you have a gas delivery problem.

Hope this helps.

[Ron61]

One other possibility not mentioned and though it is unlikely it did happen to me and one other person here. Our cars were doing the same thing and it was just as if you shut the fuel off. Coast over to the side of the road, wait a while and it would start right up. After two months of trying everything I had it up on a friends lift and we had it running and just happened to be looking at the rubber fuel line. All of a sudden it just sucked closed and the car died. We took the line off and it looked and it looked and felt great but I got a new one and replaced it and never had that problem again. Same for the other guy after I told him what I found. And the part of my line that collapsed wasn't in the hottest location either.

Ron

[undy]

It could be an ignition module (not knowing which distributor your using) or a MSD box intermittent failure. You could have a resistor/diode/etc that's heating up and cutting out. As it cools the system starts working.

Carry a known-to-be-good spare spark plug and pull a wire when she dies to see if you've spark. Another thing... as soon as she dies, pull her over to the side of the road, pull a spark plug to see if it's wet.. wet plug = no spark and a dry plug = no fuel..

Dave

[CobERA]

Guys, thanks for the replies.

I've received a few other suggestions and have a little more information.

One additional clue is that I experienced sudden, dead silence. No popping, missing or surging before the car died.

I also spoke with MSD, since I have an MSD distributor, coil and the 6AL box. They told me that the Blaster Coil 2 should not be mounted sideways. I have mine mounted sideways on the front left corner of the intake manifold. My coil is brand new (since the first stall) and my old coil was mounted the same way. Do you think sideways mounting could be the problem.

Also, it was suggested that it could be a bad magnetic pickup in the distributor. I'll try to check that tonight.

[patrickt]

Originally Posted by CobERA

My coil is brand new (since the first stall) and my old coil was mounted the same way. Do you think sideways mounting could be the problem..

No, there are a zillion MSD coils mounted that way. The fact that it is dying on you regularly will actually help you. Put a can of starter spray in your trunk and, like Trularin said, when it dies, quickly try and start it with a couple of spritzes down the carb. If it doesn't start, pull the wire to plug #8 and hold it while you crank the ignition key (you can easily reach both). I'm betting you won't get any shock and, if I'm wrong, it won't hurt that much anyway. Doing those two things will get you closer to the final answer.

[Jerry Clayton]

you could have some stray electrical current flowing thru the braided wire covering on your fuel line----this would made a little fuel line toaster and could cause vapor lock---poor grounds( fiberglass cars and boats) cause some wierd electrical things to happen

Jerry

[patrickt]

Originally Posted by Ron61

...the rubber fuel line. All of a sudden it just sucked closed and the car died.

That's a great tip. I've never heard of that happening. I take it your line looked something like this?

[Chaplin]

The other thing when it dies is to check the float boals and see if it there is gas in the bowls. If the fuel line collapsed and it died because of no fuel, you will not have any gas in the bowls. If there is gas in the bowls, then you know it is an ignition issue- then try partick's suggestion to check it.

[RACER X #99]

The MSD box is bad. All pro race cars carry two MSD boxes. Guess why?

[Chaplin]

Originally Posted by RACER X #99

The MSD box is bad. All pro race cars carry two MSD boxes. Guess why?

It's not the box, it's never the box. Just ask Turk.

I'd bet module in the distributor or coil.