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My 71 LT1 has a newly rebuilt distributor by Mr Dave Fielder T.I. Specialist, + new ignition coil, I rebuilt the stock Holley 4150, the amp is new-generation, fuel pump and filter is new, sock in fuel tank appears clean and new. 11,000 miles since engine rebuild. All stock except I kept air pump off and upgraded to roller cam. What the heck is causing me to die on the road a mile or two from home? I have to wait for things to cool down then it fires up and runs just long enough to get me back home. Ran fine until I hit 11,000 miles, started having issues running over 2000 RPM so I rebuilt carb and started replacing, and rebuilding again. Would a vacuum leak somewhere or anywhere cause this? So frustrated.
Dies when it gets hot does not sound like a vacuum problem. Sounds like your reaching there.
Dies when it gets hot sounds electrical.
Possible failing coil.
I replaced the ignition coil in May, appeared to be new and was sold as new. OEM Delco Remy for TI. Divorced choke set up maybe? I think my fast idle cam is not right. I'll post some pics and maybe someone will see something Before carb rebuild Before Before After carb rebuild. Is fast idle cam supposed to pivot below tang when warm? View inside TI amp module. Checked ground, seems fine.
Last edited by Desi.LT1; Jul 6, 2024 at 11:47 AM.
Reason: Adding pictures
I think you're going to have to do some on-the-spot diagnosing.
How about only driving 1/2 mile away and back so it dies in your driveway? 😉
Seriously, when it won't start, you need to check for adequate fuel squirt in the carb and spark at a few plugs. At least this will help focus where the issue lies. I'm not familiar with the T.I. components, so maybe someone here can help with how to test them with a multimeter.
Thanks for the help everyone. Will keep trying. When it dies at first on the road, I can see fuel squirts when manually moving throttle. Need to try again and see if fuel squirts still exist after limping into my garage! Usually too pissed to get into it. I definitely limit the test runs!
Get a can of Dust Off and when your engine dies, spray it on your coil, condenser. Try to start the car. If it does not start, spray the TI module. If the car starts, you have narrowed down the faulty component. Dust Off will sharply drop the temperature of whatever you spray it on. You can do the same with carb cleaner if you suspect a fuel problem. Spray the cleaner into the carb and see if the engine starts and runs for a few seconds. Make sure the carb cleaner is the old style which is the combustion type. Some of it is not. Jerry
Mine failed many years ago, similar to yours, started when cold. It was a faulty pick up coil in the distributor. I replaced the coil itself, not had a problem with it since.
The replacement is called a "Bobbin".
Check the lead wires coming out at distributor magnetic pickup coil. The constant movement from the vacuum advance cold works the wires. Then heat can cause them to slightly separate cause a no start and or shut down.
People always say when a fuel starvation issue is suspected, then pull off the road, pop the air cleaner, look for squirts down the carb.
Well, this test only proves that fuel is in the accelerator pump well. It does not assure there is fuel in the bowls. Especially on Holleys.
Just a couple of observations here:
At one point you had a rubber fuel line from the firewall? and splitter block to feed the primary & secondary bowls.
Then later you switched to a single steel line from the pump. I see no fuel filtering system, so I question if crap in the lines is interfering with the needle & seat.
I also find it strange that your distributor Vac Can is not traditionally pointing at #2 cyl. I guess that is for easy access to the "dwell window".
And I find it strange that a vacuum hose comes off the secondary throttle diaphragm and goes all the way around the engine to pick up the PVC system. H-m-m-m-
Meanwhile, #8 Intake runner has a vacuum plug just sitting there.
And last, how do you ever set the Idle Mixture Screw on the passenger side?
Fuel squirting may not be foolproof, but it does lend itself to determining why it won't fire. If it were a squirt or two, it should still fire off. Another check, which is a Holley advantage, could be removing the sight plug to determine fuel level by sight or even a small dipstick sort of thing.
The vac can 90° to engine is something Chevrolet recommended for small blocks in '68 so that there was no tach drive interference. Not sure why they only issued the service notice for small blocks, I have my BB in the same orientation for the same reason.
Don't all Holleys have the PCV port on the passenger side of the carb? I know my original '67 Holley does and the PCV is routed much the same in the AIM.
That idle screw is certainly blocked but I bet the Snap-on guy has the perfect screwdriver!
Last edited by barkingrats; Jul 13, 2024 at 10:11 AM.
It dies like it's stumbling over itself. Not like key shuts off. Maybe squirts are short lived and is just what remains in pump. I opened the primary bowl today, checked the inlet valve to see if sticky. It's new since carb rebuild with virtually no miles but car has been sitting for months. Valve seems fine though. So I plan to try again today and check sight plug for fuel level instead of relying on"squirts". There is a new fuel filter between fuel pump and carb. Fuel tank is new 10,000 miles ago in 2019,no rust. Idle screw on pax side is accessible below the vacuum bracket with normal screw driver thankfully
Last edited by Desi.LT1; Jul 20, 2024 at 03:43 PM.
You should have quite a few squirts if the bowls are full.
First ground I'd check is for the engine — on my '72 it's under the engine mounting horn on the passenger side – it's a very short cable from the frame to the side of the block or forward starter support bracket. Has the engine been painted in this area recently?
Desi,
Remembering your fuel supply plans and changes you made from pump to carb, I have to ask:
Was there or is there the all-important "S" hose mounted near the pump?
@PCC, I see the cable, is actually one I replaced about 9k miles ago. Seems okay still. The block was fresh paint when I replaced the old cable in that area.
@Lemans Master, yes I do have the S hose feeding the fuel pump.
71 LT1 starts fine, idles fine, dies on the road
