Isuzu pu engine racing


#1

yesterday while driving my 92 isuzu pu 2.3 suddenly went up to what appears to be full revs and now will only run at full revs never going back to regular idle speed any ideas as to the cause or solution


#2

Can you verify that the throttle plate is closing? Sounds like a stuck throttle cable.


#3

the throttle cable is slightly loose with no foot on the pedal and tight with foot on and appears to be working normally including the pedal itself, the cable all the way up to the carb attachments


#4

Are you saying this has a carburetor and not a throttle body?


#5

+1 for @insightful . The truck does have a carburetor if it is has the 2.3 engine. In fact…82% of 92 Isuzu trucks had them. Check the carb by looking down the throat. If the throttle plate is wide open (I believe it is) then you need to get some work done on your carburetor.


#6

any ideas as to what part of carb could be the cause and would a carb cleaner help?


#7

Have you taken the top off the air cleaner and looked down the carb throat yet? Move the throttle by hand while looking at the throttle plate. You may see something loose or otherwise odd.


#8

Check the secondary throttle plate. You might be able to look down the throat to see if the plate is completely closed. This is a demand, vacuum diaphragm operated shaft. If the shaft becomes gummed up because of minimal use, it can stay jambed in the open position. Try pushing it closed. To correct the problem clean the shaft with carburator cleaner spray while you work the shaft open and closed.