Injection pump experts pls. help

[2ma2]

Rebuilt motor, timing set,Linkages set, car runs Ok but I think I have it set too lean. Not much power over 4000 rpm and it is smooth at 1200 rpm and above. below this it is lumpy. Also after a test drive the idle stays at about 1500 rpm. Is this a lean condition. any help appreciated.

[aa/fd]

On the surface it appears that yes the overall mixture is weak, they will really fall off at 4000 plus when over lean condition exist.

But, I would review the linkage, ignition timing advance curve, and warm up regulator setting before proceeding.

Not knowing the disposition of the engine prior to the rebuild I am just guessing. If it ran ok before, then there is likely and assembly issue. Meaning, pump timing, intake (vacuum) leak, ignition timing, or a non stock cam profile can be a real issue.

[Richard]

When the pumps fail 9 times out of ten they go very rich..... Check your warm up device.... Tailpipe,plugs etc....

[2ma2]

thanks for the replies, warm up device is good and car starts fine from cold. there does seem to be a lot of travel until the mixture screw hits it's stop. About how much in mm or how many threads show below the bottom of the enrichment lever on your cars. thanks

[Richard]

I will be roundel?? debunked for saying open the pump top. The plate that controls the amount of gas(mixture) sounds like its binding....

[aa/fd]

Mine has about one thread showing above the lock-nut of the mixture screw.