S4Cruiser
SILVER Star
Still learning my way around my new to me 40 and have new questions/need some help.
I'm working with a rebuilt 2F with ~40k miles, '77 Toyota Federal Carb (desmogged) and 60 series large cap distributor w/coil/ingnitor.
I've corrected the PO's vacuum line connections on the carb per Jim C's direction, new plugs, new OEM PCV valve, OEM air filter and new Koyosan mechanical fuel pump (diaphram in the original one was failing).
Didn't idle that bad when I got the truck but idled high. I bought a tach to attempt to set the idle per the FSM at 650 rpm with no luck. It idles very rough and erratic when set near 650 (or as close to it as I can get it). Sounds like it wants to die then will randomly rev up to 1k or so. The truck runs fine at speed and while accelerating. When coasting to a stop it wants to almost die then rev back up 1k or so with no throttle and then will eventually settle back to 650 or so running rough.
Could this crappy idle be due to a vacuum leak? I tested manifold vacuum at idle and it was all over the place due to running rough. It held steady around 20 at 1k rpm.
Also:
Had been meaning to do a compression test so figured I'd start there. Truck had been driven around the block, parked for 30 minutes and then I did the test so not sure if it was warm enough. Disconnected the coil, removed all plugs, tested each cylinder with the throttle open (cranking over what sounded like 5 times or so).
Does this sound like the proper way or should I redo differently?
Here are my numbers -
1 - 140
2 - 130
3 - 130
4 - 135
5 - 130
6 - 140
I assume these are ok but not great. Thoughts?
Any idea on where to start/what to check to help cure my crappy idle??
for the help!
-Jon
I'm working with a rebuilt 2F with ~40k miles, '77 Toyota Federal Carb (desmogged) and 60 series large cap distributor w/coil/ingnitor.
I've corrected the PO's vacuum line connections on the carb per Jim C's direction, new plugs, new OEM PCV valve, OEM air filter and new Koyosan mechanical fuel pump (diaphram in the original one was failing).
Didn't idle that bad when I got the truck but idled high. I bought a tach to attempt to set the idle per the FSM at 650 rpm with no luck. It idles very rough and erratic when set near 650 (or as close to it as I can get it). Sounds like it wants to die then will randomly rev up to 1k or so. The truck runs fine at speed and while accelerating. When coasting to a stop it wants to almost die then rev back up 1k or so with no throttle and then will eventually settle back to 650 or so running rough.
Could this crappy idle be due to a vacuum leak? I tested manifold vacuum at idle and it was all over the place due to running rough. It held steady around 20 at 1k rpm.
Also:
Had been meaning to do a compression test so figured I'd start there. Truck had been driven around the block, parked for 30 minutes and then I did the test so not sure if it was warm enough. Disconnected the coil, removed all plugs, tested each cylinder with the throttle open (cranking over what sounded like 5 times or so).
Does this sound like the proper way or should I redo differently?
Here are my numbers -
1 - 140
2 - 130
3 - 130
4 - 135
5 - 130
6 - 140
I assume these are ok but not great. Thoughts?
Any idea on where to start/what to check to help cure my crappy idle??
for the help!
-Jon