406 help

[emtb85]

Put a 406 in the car and we can't seem to get it to run right. It sounds like it has a miss or has a hesitation when you get on the gas. We just had the motor going threw and everything looks good. Class says we have to run a 2bbl carb. Bought a brand new carb, new plugs and wires and new distributor. Any suggestions on what else it could be? Thanks

[js11]

check your fuel filter and make sure the fuel pickup is RR corner of fuel cell. Also, coil or wiring at toggle switch (loose wiring, etc). Good luck.

[emtb85]

Thanks will go threw the wiring tomorrow. Would a stock fuel pump be to small for it because sometime when it's running it doesn't look like any fuel is going threw the fuel filter and other times you can see it coming threw it. But either way it still seems like a miss starts about 3,000-3,500

[js11]

Not sure what a stock fuel pump puts out, but if you're running gas you need a 9lbs pump, for Alky a 10 to 15 lbs pump (make sure your fuel bypass or regulator is set correctly for the correct fuel pressure at idle). Also, an old fuel filter can cause you problems. Make sure it's not obstructing fuel flow. Perhaps someone else on here can answer your stock pump question with more certainty.

[Fox_hunter42]

406 will require alot of fuel. Maybe to lean, maybe vacuum leak,

[emtb85]

Thought we had it figured out one of the clips on the distributor cap wasnt latching tight enough and letting the cap be a shade loose. fixed it and seemed to run right. When out today started it and its right back to doing it. Changed fuel pump and still no help. The carb is a speedway 2bbl cfm cab. Would that be to small? Also gonna change plugs again any suggestion on what would be the best to put in it and whats the best gap range for them. Thanks

[purestock45]

check your tach....

[emtb85]

I took the tach clear out and it never did help

[72Dubya]

Pull out your plugs. If the ends are black or dark brown, you are running too fuel rich and need to either jet down one step until they are light brown to white or adjust your idle bleeds.

[72Dubya]

And gapping the plugs to .035 is a good basic rule of thumb unless engine builder says otherwise.

[let-r-eat]

Has the car been raced and the miss was at 3-3500 rpm's and stayed missing until you let off the throttle?Was the car under load is what I mean when it was missing? Or are you just hearing it in the garage free revving the engine?

[Dirtrunner35]

In my old stock car I bought a brand new carb and ran it less then 40 races and took it off, it felt like a miss at 5000 rpm, put my old one on and ran great. choke and spits are junk, 800.00 for nothing, Check your grounds