engine/idle problem and I need help (1 Viewer)

[FE427TP]

Here's what I have....
74 FJ40 with the F engine, it has started to idle poorly and miss badly and will not rev at all, I have rebuilt the carb, put new cap rotor and wires in along with new plugs points and condensor and threw in a MSD i had trying to fix this. I did a compression check a while ago before this started and everything read fine and i have no reason yet to believe this has changed no oil in radiator and no water in the oil that I've noticed I haven't adjusted the valves but they aren't making any noise either. Right after i rebuilt the carb it felt like it was idling alright but the next day it barely idles and i couldn't time it since for whatever reason the #1 cylinder wasn't firing which is when i replaced the cap rotor and plug wires i have tried driving it but all the more speed it'll get is about 20 miles an hour in second gear floored, there is no fuel coming from the secondaries and the float bowl is spot on

any ideas for what to check/replace next?

 

[Poser]

Just because the valves * are not making any noise* does not mean this is a good thing....


After you changed cap rotor and plug wires, did you have spark to all the plugs?


You state that you have rebuilt the carburetor. Is this something that you have done with success in the past? Are you positive that everything is back in the carb where it belongs?


Are you sure you do not have a vacuum leak someplace?

 

[e rock]

First things first: You need to get the timing set correctly. If there's no spark to cylinder #1, you gotta figure out why.

If you can rebuild a carb, you can adjust your valves. If you don't know or remember when they were last done, just do it.

IIRC, a 74 carb has vacuum secondaries, so that symptom may just be ancillary to your other issues. Ditto what Poser said about checking for vacuum leaks around your intake manifold gasket, the base of the carbm and the carb body itself.



Report back.

 

[FE427TP]

After you changed cap rotor and plug wires, did you have spark to all the plugs?

I'm going to say yes because I also just went out and ran some 600 grit sandpaper on the point contact surfaces and the idle smoothed out a lot but I'll check again

You state that you have rebuilt the carburetor. Is this something that you have done with success in the past? Are you positive that everything is back in the carb where it belongs?

I've rebuilt a autolite 2v in the past with success and swapped my holley double pumper over to the proform main body. I'm not perfect by all means but I also made sure to lay out everything I took off the carb onto a shop towel and nothing was left on it that wasn't something I replaced but the one part I didn't take out and change was parts number 27 and 28 from figure 3.1 in the haynes manual the check ball retainer and check ball under the accelator pump it looked like something very likely to break while trying to remove so i left it alone

Are you sure you do not have a vacuum leak someplace?

i tried spraying starting fluid around the base and didn't notice anything but it was running rough so hard to tell, I haven't tried the vacuum tube stethescope idea yet. I am also thinking of swapping back to the old condensor just to see if the new one was junk out of the package i noticed it was a 15 microfarad and the old one was 22 so maybe the old owner had to bump it up

 

[FE427TP]

well i ended up resetting the point gap and have the timing currently set at runs (like a violated simian compared to before) good but doesn't ping and think I'm not going to try to "fix it" until something breaks i figure what must have happened is at some point maybe the battery got bumped hard enough or something but my timing must have went really retarded which lead to the other problems