1965 Ford Thunderbird
390 FE V8

I recently replaced the intake manifold with an Edelbrock Performer RPM and now she won't keep running. There are no vacuum leaks, or anything else visably wrong.

The car ran just fine (maybe a small exhaust leak) before I replaced the manifold, and I put everything I took off back on again. In the meantime I have rebuilt the carb, replaced the coil, distributor, cap, ignition, starter relay, voltage regulator, and rechecked every wire I can find. Still, she does the same thing everytime; Starts, and will keep running for up to 30 seconds if I keep pumping the gas pedal. I also checked the fuel lines, and the carb is receiving ample fuel to keep her alive.

I really don't know what to do next.
Any help would be really great, thanks!

recheck the float level in the carb, and also make sure the float is not stuck.

I did when I rebuilt the carb a month ago. Everything is up to specs according to the manual.

Try a carb off another motor (A carb you know is O.K.)and see if your motor keeps running, that way you will know if it is/is not your carb.
Sounds like lack of fuel due to either poor pump, low float-level or blocked jets.

If car runs when you pump the accelerator it's most likely something in the carb. Does the fast idle set when you push the pedal? I've had carbs that were rebuilt turn out to be faulty. It might also be a bad fuel pump

I initially ruled out the fuel pump because I get enough gas to the carb for it to fire.

I also took the fuel inlet pipe off the front of the carb and turned the car over and received about 2-3 ounces of gas.

Alas, another carb is in my future I think. That, and plugs and a battery. Not because I need them, just to be thorough. Replaced just about everything else already.

I haven't been able to see how the carb reacts when I push the pedal as I am doing all of this solo.

Thanks to all.

Pump the linkage from under the hood and look in the carb. You should get a stream of fuel on both sides of the front barrels.

If it ran okay before you switched manifolds --what does that tell you.

it tells me that Edelbrock shouldn't say these manifolds work on these engines.

Go to Fordfe.com
Maybe they can help you.

Did you find something wrong with the intake manifold? Did it not fit correctly?

Fits fine as far as I can tell. It does seem to be a bit taller than the stock manifold, but I don't know if that is a deal breaker or not.

I'm going to try pumping the linkage later on tonight, thanks Tim.

If you go to the FE.com site these fellows know all about problems encounterd with switching manifolds and other problems, if you go there I'm sure they can help you

still waiting to be accepted as a 'member' to be able to post.

I think you have a major vacuum leak.

after thinking about it you must have a vaccuum leak somewhere on the manifold. It's kind of hard to pinpoint because you have changed so much. if you have a vaccuum leak my guess is that it is between the manifold and the carb. spray carb cleaner around the carb with the engine running, you will need someone to keep it running and see if the engine speed increases. That would indicate a vaccuum leak. also check all the connections on the manifold especially the hose that goes from the intake to the brake booster. if that is leaking the engine won't idle at all.

What carb.do you have, it should be a Ford 4100--a very good carb.
Try removing the carb. and check the mating surfaces to the manifold and spacer.
I'm sure you have checked the connections to the power brake booster, tranny.
However, it would take one hell of a vacuum leak to cause your problem.

I think you guys might be on to something. I looked closer at the carb/spacer/manifold area and it appears the spacer is a bit bigger than the manifold surface. I don't know for sure how big of a gap there is, but it's there. Going to remove the carb and take an even closer look ASAP.

Is there any recommended sealants that can be used in that area. Some of my permatex sealants say to not use near gasoline, while others did not.

Thanks again guys

If the mating surfaces are true good gaskets will do the job

I think you guys nailed it. I removed the carb and spacer and found a big gap underneath the backside of the spacer. That notch for the PCV vacuum line - to the valve cover.

The stock manifold is almost completely flat, so the gap is covered by the manifold. The Edelbrock manifold is raised for the carb only, and the gap is exposed.

I'm getting a 1/8" carb spacer fabricated to cover the gap, and with an additional gasket and longer carb studs, I think I should be good to go!