Hi all,
I have a new engine, new carb, LOTS of time spent under the hood and the same thing keeps happening. She will run good one day and like crap and leave me stranded another day. I've been told its ignition issues, fuel pump, gas tank issue possibilities... Fires right up, go to give it gas and it dies, it will die while I'm driving down the road, die when I turn into the parking lot... Dies at any given time and then the next time she drives just fine...CRAZY

I don't want to keep spending $ and other people's time for the exact gremlins to keep popping up. Yeah I know that's the name of the game in restoring cars but there has to be something crazy simple that's just missing here....

Where should I start?
Where are the ground wires located, so I can check those connections?

I had someone tell me today that if its a fuel pump it wouldn't intermittently work and not work- is that true?

suggestions??
hellllpppp...lol

 

Mechanic fuel pumps sometime split the diaphragm and leak. Sometimes they just puke. Sometimes the lobe wears off the cam. But never heard of them kicking in and out. But stranger things have been known to happen.
I'd be looking at the module in the HEI distributor myself.

 

New carb, new engine and lots of time under the hood tells us about next to nothing.
Can you describe what you have in detail?

Jebby

 

I put a 350 crate engine in it, a 650 Holley carb, Holley Pump discharge nozzle (not sure what this is) HEI Distributor. I'm going to see if I can tag Steve one of the guys in the car club that has been helping me out with this a lot- he will be able to give you the detail you need- sorry, I'm not so savvy with these things..

 

FWIW: based on your description, check the HEI.

 

Ok Peoples...here goes. This car sat for a number of years before the guy got around to installing the crate motor. When he did get it in, we went over and got it running. Ran like crap. I towed the car up to my house to get things squared away. I don't remember if I replaced the carb first or the distributor. Both were not in good shape. I (she) got a Holley 650 Demon practically new. Had a little trouble with that, but got it straightened out. Next up is the distributor. Original was junk. Got a used from a friend of mine. Ran great for a while. Than it started to act up. Would run and just shut off for no reason. Start right back up. I bought a new one and it was better. That one crapped out also. Got another, under warranty, and it seems to be ok. Now, The only timing reference I had to go by, is a piece of tape with a mark on it that the guy who installed the motor said is TDC. There is no timing tab or notches to set it by. Can't tell you how many times I "set" the timing. Finally go it to the point where it would ping going down the road. kept adjusting distributor until that stopped. Car ran great, drove it around for about a week, burned up a tankful of fossil fuel. Took the car back to Misty, she lives about 40 miles from me. Ran GREAT the whole way. Some time later she calls and tells me it's stalling out again. Fire it right back up and go.
I am stumped on what this thing is doing.
BTW, I also installed a fuel pressure regulator and have it set to 4-5 lbs.
I'm beginning to wonder if it's a fuel pickup thing. BUT, when it does die out the bowls are both full
Does this year Vette(75) have a bladder? Maybe it's collapsed? I don't know.
As far as the timing goes, I set it according to Lars procedure.
Bad ground? I looked those over and they were there and looked ok.
The one thing I have not replaced is the plug wires. It does have new plugs installed.
This is the one time I wish there was a computer hooked up. Much easier to diagnose.
All I can think of that I did and WELCOME your thoughts on what the hell is going on.

 

Go to the back of the car near the sending unit on the gas tank and replace the 6” section of rubber fuel line.....it can fail internally and collapse at times, other times not.....
Then pull the fuel line by the pump and verify that you have free flow....just pull the supply line off for a second and fuel should just run out immediately....
Do this first.
How are you setting timing with no timing tab? Dial back light and a mark? Explain.

Jebby

 

There is a piece of tape on the timing cover that the guy who put the motor in put on there. He then marked it with a sharpie and also a white stripe on the balancer after finding TDC. I have an adjustable timing light that I use.
She is, hopefully, bringing the car back to me this coming weekend. I can pull the fuel off then.

 

Find TDC and install a tab......I would not trust that TDC mark at all. Marked with a sharpie.....nice. Moroso makes a nice tab that is spot on out of the package.....if you double check the TDC and did the Lars method then you can eliminate this as a variable.
There have been a couple of distributors in this engine.......check the large 12v wire going to the BAT terminal.....I assume this is an HEI. Check that wire all the way back to the fuse box and check the voltage at that wire. It needs to be a 12ga wire too......if it is not already.

Jebby

 

Verify the timing marks are actually TDC. This is not your problem of course.

I would be pointing to the HEI with my gambling money. It sounds too much like an HEI problem. Do not bother trusting "improved" HEI hop up parts here. Need to use a quality standard coil, standard module and the proper heat sink paste under it. Been here before myself....this is what it was.

 

I had something similar to this on my 69 427 with factory Trans ign many years ago. Different distributor, but the results could be the same. There was a rubber grommet where the wires left the distributor and the wires had found a gap in the grommet and were touching the casing.
the car would idle fine or run at WOT but in between the results were uncertain. When the advance rotated the internal wiring the wires wore through the insulation and would touch the housing. If they touched lightly the car would sputter and if they touched solid the car would die. I had to repair the wires and install a new grommet and that fixed the issue.

 

Yep, had that happen to me also. Going to check that when she gets the car here.