AMC-2.5 idle change ?

[AMC-MJ]

My engine once heated up normally idles at 750rpm nice steady and smooth . . . Now the idle has dropped to 625-575rpm and it has a bit of a shimmy or shake to it . . .

 

What would cause this to happen ?

 

i been driving the truck everyday 3times a day for 9Mo this is the first i have seen it do this . . .

 

Mike

[dasbulliwagen]

You might want to check to see if the idle speed actuator is still working or if it has come unhooked. It is a little plunger like device that pushes on part of the throttle linkage at the throttle body. Sounds like it might not be working like its supposed to. Good luck.

[AMC-MJ]

I may have to check that out, Is it the same unit that controls the high idle on start up ?

 

If so next drive i take i will see if i notice the high idle working or not . . .

 

 

Mike

[AMC-MJ]

I removed the motor speed adjuster cleaned it all up and shot some grease onto it, and so far it working idles holding at 750rpm not sure if it was a cure or just a stall . . .

 

tho the 750rpm idle is not smooth like it once was checked air filter nice and clean, tune up time again ?

 

Mike

[Curt]

Check for a vacuum leak. Get a can of carb spray and with the engine idling, spray around the TB and the vacuum lines. Any change in idle speed will indicate a leak.

[AMC-MJ]

I will give that a try.

 

 

Mike

[AMC-MJ]

:cheers: Idle is fixed :cheers: It was an exhaust leak goofing up the idle :fs1:

 

:bowdown: Run's like a TOP now

Mike