Okay I'm posting this for someone else with a '91 Toyota pick up truck, 2WD, reg-cab, 22RE, 5-spd. The truck has about 140K miles.

This may be difficult to put into words, but I'm going to try. Basically the truck has some type of a vacuum or gasket leak somewhere. When you start it up the engine revs to idle then bogs and continues to do so. Sort of like this:

Rev...Bog...Rev...Bog...Rev...Bog and so on.

Is there anything specific to these engines where this may be a common issue? What should we look for in attempting to solve this problem?

Thanks in advance for any help.

 

Did you check the timing?

 

sounds like an idle surge could be a vacuum leak and it could also be that the idle speed is set to high.

 

Eh,

sounds like it could be the classic idle surge.

sometimes the idle adjustment screw located on top of the throttle body tends to back off over time and causes this condition which is not necessarily sympomatic of the resulting condition, but is very typical.

try turning the screw clockwise and see if that cures it.

give a shout if you need help locating th idle adjustment screw.

Good luck with it !
Pete

 

errr,

sorry toyota offroad, just noticed you noted the same thing.
Pete

 

Try spraying some starter fluid around the throttle body, intake, and vacuum hoses. If the rpm's bog and stay there for a bit, you have a vacuum leak. Check your hoses, you might need some gasket sealer.