FJ60 Vapor Lock? (1 Viewer)

[stoshzack]

Hi All -

Another interesting issue with my 1987 FJ60.

The rig drives fine on flat land. Only when I drive up a hill in 4th gear does it begin to hesitate. Eventually it will just die out (kind of scary). After I get it (i.e. coast) onto flat land for awhile (and restarted), it begins to drive fine again. On the fuel side - the fuel pump, fuel filter, and gas cap are new and I rebuilt the carb (hopefully correctly). On the ignition side - the dizzy is rebuilt, the spark plugs, wires, and coil are new. Also, I have blown out the charcoal canister with compressed air thinking it might be a vapor lock.

I have always had trouble starting this FJ60 as compared to my FJ40. It can sometimes take 10 or 12 presses of the gas pedal to get it to start. Sometimes it starts just fine. When I got into it the other day, I pressed the gas pedal a couple times to start and heard a "gulp, gulp, gulp" sound from the gas tank. That, combined with problems on the gradual hill make me think it is a vapor lock or some air pressure problem.

Any other areas to investigate is greatly appreciated.

Thanks,
Stoshzack

 

[Output Shaft]

Driving it with a rag stuffed in the fill pipe will rule out venting issues.

Hard starting can be caused by several things, but a worn accelerator pump plunger will prevent gas from being squirted down into the manifold when pumping the pedal, making starting difficult.

Although your loss of power driving up an incline may be different from exactly the same symptom I was experiencing (engine running out of fuel/power going up hills), the cause of my problem was a small piece of crap drifting around inside the float bowl, intermittently clogging the primary jet.

When the engine is tilted up, when driving up a hill, the jets are tilted down, and in my case, that was just enough of an angle to allow that little piece of crud to drift up against the jet.
On flat ground the engine would run better. After I took apart the carb and found that tiny piece of crap in the bowl, and replaced the accelerator pump, the problem was fixed and the engine ran fine.

I say it's time for a carb rebuild.

 

[stoshzack]

Thanks @Output Shaft

I'll go back and look at the carb.