Topic: 1980 20r Stumbly Idle...

[H8PVMNT]

My '80 4x4 runs like a top overall and gets 20+ mpg, however, the idle is kind of jumping around all over the place.  Nothing to extreme, just a little erratic.  The carb runs awsome at angles and the truck fires right up with just a turn of the key, which leads me to believe the carb does not need to be rebuilt.   The head is not leaking. 

I heard somewhere about a "anti-deiseling solenoid" that often needed to be re-grounded to solve this idle problem.  Is this for real?  If so where is it, on the carb?  Should I be looking for vacuum leaks?

The truck runs so good I want to finish working the little bugs out of it.  Any suggestions?

[79coyotefrg]

what do you mean by "erratic idle"

it sounds like maybe someone installed a hi lift cam, have a listen to mine--> http://www.mhdfl.com/forum/Glens-truck.mp3   thats a LCengineering stage 2 racing cam,  if so there's nothing that can be done but grin from ear to ear going down the road

[H8PVMNT [OP]]

Maybe that's it.  It kind of sounds like that, but with quieter stock exhaust.  Somebody did put a decent header on it and it does haul ass down the road pretty good.  I'll have to check it out.

What are you running for exhaust?

[79coyotefrg]

Maybe that's it.  It kind of sounds like that, but with quieter stock exhaust.  Somebody did put a decent header on it and it does haul ass down the road pretty good.  I'll have to check it out.

What are you running for exhaust?

when that sound clip was made, not much


now i'm running a long tube header (old LCE i think) 2 1/4 inch tube back to a 20 inch glasspack, about 8 inches of tube past and a turn down

[RN37DD]

The anti-diesel or fuel shut off solenoid is located on the side of the carburetor, it well have a wire or 2 leading to it. my 20/22r idles a little rough at idle, because i have it turned down to keep it from dieseling when i shut it down. I don't have a solenoid. If you have an egr valve it may be leaking by some. but as in above, even a mild cam well cause a little stumble at low rpm's. what is your idle rpm set at?

[H8PVMNT [OP]]

Idle is set at about 850-900.  Any lower seems to low. 

Because the header has no hookups for the egr somebody before me just left the pipe hang there and pinched it off. Could that be part of te issue? Maybe should I do a proper delete with the block offs and such?

[79coyotefrg]

yes you need to get rid of that pipe and block off the ports

[H8PVMNT [OP]]

Do you guys have a good source for block offs or should I just make them?

[79coyotefrg]

i made mine from a piece of 1/8 inch steel