nkaner85

I was on the freeway driving, then all of a sudden it started to bog out. Got it home and it looked like my carburetor looked clogged and so I rebuilt it. and nothing changed and I messed with that for awhile then a just bought a carburetor as close to the old one that a could . Nothing changed so a replaced the fuel pump and the fuel lines plus filter. It'll start up if I put carb cleaner in the carb but it wont stay running and sounds pretty rough. I also put new plugs in too. I've tested vacuum to the mechanical fuel pump and it at around 4 and I think it should be 10ish. I want to fix it but I'm kinda lost on what to do next. Help!?

Coronet 500

Have a look at your fuel pump push rod, they can wear, shorten and reduce pump lever travel.

nkaner85

Thanks I appreciate the help. I'm close to throwing in the towel and take it to a shop. I have pulled the rod and it looks good to me. talked to me dad he recommended pulling the distributer.....what do you think?

Archer

n -

Fuel pressure at the carb should be about 6 pounds. Setting up a cheap fuel pressure gauge close to the carb inlet and seeing if the pressure drops might tell you something.
Regarding the rod, you have to compare it a good (new) rod or check the specs for length. If it's even a little worn, it can effect fuel pressure. While rarer, the fuel pump excentric on the cam may be worn.
If you think it's the distributor, look at the spark plugs, see if they are wet or dry and the color.
There are charts on the net to help diagnosing that stuff.

Archer

RacerHog

Check the Point adjustment..

nkaner85

I have got my timing correct enough to get it to run but still not enough fuel to the carb. I have bench tested my fuel pump and its good but when I put it on the car it doesn't have enough vacuum. i haven't done a pressure test on the fuel pump yet but I'm going to. I'm going to check my points to make sure they're correct too. Thanks for all the help!

nkaner85

it was the fuel pump push rod , it was about a 1/4 in. short!

Archer

n -

I've seen that happen, but still having a problem understanding "why" it happens, unless the rod was made from a really cheap metal.

Archer

nkaner85

the length it was suppose to be
it looked like it had a tip on it that was different from the rest of the rod cause it looked like it was sheared off, rough edges and no marks like it had been rubbing on the cam. I'll send pictures in a minute

Iowan

The fuel pump rods just don't get replaced or checked most of the time unless there is a problem.

fivepoint

Would this be another reason to use an oil with zinc in it or use a zinc additive?

Iowan

It works like a flat tappet.

fivepoint

Exactly. They went to electric fuel pumps around the same time they went to roller lifters.

Iowan

And EFI but the big blocks were done in 78.

nkaner85

I'm cruising now ! I just need a colored wiring diagram because I'm having some trouble with my lighting and radio. The service manual I have isn't as detailed enough for me, a not so mechanically advanced person so sometimes I can't figure out some of the wiring diagrams.

does anyone have color coded wiring diagrams? Or advice?