81 FJ-40 - Hesitating / bucking under acceleration (1 Viewer)

[pb4ugo]

That's good you got the idle down. The difference between the 60 and 40 could be a difference in timing adjustment .

 

[charliemeyer007]

You can time an engine anywhere if all the stuff lines up correctly - its way easier to set it up by the book. Usually you can adjust for one tooth out.

 

[AYM707]

Hook a hose to the distributor vacuum advance port and suck on it. If you can suck air means its' diaphragm is bad.

Ok...not sure I understand?

I have vacuum advance. As per the FSM clipping, while the engine was at idle, i sucked on the tube connected to the vacuum advance. The engine RPM do not increase nor was I able to suck any air out of the vacum advance. So diaphragm is good, but vacuum advance is not working??

That's good you got the idle down. The difference between the 60 and 40 could be a difference in timing adjustment .

so its better to keep RPM lower, say 570-590? its ok?

 

[charliemeyer007]

The diaphragm could be good but that doesn't mean the mechanism is working.

 

[pb4ugo]

Ok...not sure I understand?

I have vacuum advance. As per the FSM clipping, while the engine was at idle, i sucked on the tube connected to the vacuum advance. The engine RPM do not increase nor was I able to suck any air out of the vacum advance. So diaphragm is good, but vacuum advance is not working??

so its better to keep RPM lower, say 570-590? its ok?

Disregard my comment on getting the idle down. I thought i was responding to different post.

If you can't suck air the diaphragm is good. It will take a bit of sucking the get the advance plate to move. You might be able to manually check to see if the advance plate is free as Charlie mentioned. You can see what the vacuum advance arm is attached too.

 

[AYM707]

The diaphragm could be good but that doesn't mean the mechanism is working.

I found a replacement advancer for $30 in Japan. that's is easy replacement