I have a 1977 F150 with a 351m that is giving me fits. It will idle OK but if I try to put it in drive it'll die and then flood. Lots of backfiring through the carb as well.

I have an Edelbrock 400 intake manifold and an Edelbrock 1406 carb. I'm beginning to suspect that the fuel pump (put on by another shop) is pumping more fuel than the carb can handle.

-How to test the flow?
-should there be a spacer between the manifold and carb?
-Any recommendations for fuel pump for this engine?

Thanks,

will

 

Is it a mechanical fuel pump? I would suspect the 1406 is your true problem.

 

Yes, mechanical fuel pump.

 

If it were me a new 4160 would be my solution to this and other future problems.

 

Instead of knee jerking and throwing money under the hood, I'd check that carburetor out. There's nothing inherently wrong with Edelbrock carburetors. Given your symptoms, I'd suspect a bad needle and seat, and or a float that's out of adjustment. The same issues that occur in Holley and other brand carburetors.

 

If it's getting "too much fuel" then the fuel pump is not the problem. I suspect like others, that carb needle/float is dirty or stuck. Most like the needle seat. Float rarely just go out of adjustment without human intervention.

Pull carb, check seat, and I suspect you will solve your issue

 

Yes there is.
If you look around you will find the Edelbrock carbs dont like fuel psi above 5 PSI.
If you check your fuel PSI I bet it is above 5 PSI and why you have flooding.
Holley carbs can work with a little more then 5 PSI I think I have seen up to 7 PSI.

Now I would also check the carb out a little bit before installing a fuel pressure regulator just to make sure the carb is in fact OK.
Dave ----

 

I've heard that myth and fretted about it also. I've never seen it. Edelbrock states 6.5 PSI. I've been running Holley, Edelbrock, and other brand carburetors for years, and have never once had a problem with a mechanical fuel pump overwhelming the needle and seats. I have however had needle and seats go bad and get blocked open in Holley, Edelbrock, Rochester, and Motorcraft carburetors.

 

"Ford 351M and 400 fuel pumps put out about 7 psi if "spot on". Holley and Motorcraft Carbs can take in excess of 7 psi due to longer float arms with large floats. Carter AFB & AVS & Edelbrock carbs have shorter float arms which is in part why they are more compact, and smaller floats and they are less tolerant of higher fuel pressures, 6 psi is the max that Edelbrock recommends for their carbs which are copies of the Carter carbs. They recommend that a max pressure used at 5.5 psi. High fuel pressure does not mean more power as many cars we considered as muscle cars used 4-6 psi. You likely need a decent Fuel Pressure Regulator like Holley's # 12-803 and use a fuel pressure tester in a tee between the carb and FPR to set pressure at 5.5 max."

If is is starting and idling then the fuel pump sounds to be ok. I would get a adjustable fuel pressure regulator and plum it in. Even a cheap Spectre or Mr Gasket FPR will work. I use a cheap one my my Bronco and I have run a Carter 4 bbl, Edelbrock 4bbl, MC 2 bbl, and now a Holley 4bbl.

 

I've had lots of problems with the Carter but I never had a problem with mechanical fuel pump pressure. it could be the problem but I wouldn't bet on it.

 

Have you got any rubber fuel lines? If you do change them out first, they are known to collapse internally when they are old and I have had my 1979 F250 act like that. Once I changed the rubber lines it ran normally. By the way , it’s a 351m with a factory mechanical fuel pump. That’s my 2 cents!

 

If you do get a new fuel pump, I suggest an Edelbrock low psi high flow unit. I installed one with my new Holley and it has worked well. The chrome finish didn't hurt either.
https://www.edelbrock.com/shop/fuel-...s.html?cat=413