myfinalcoffin

My 1990 3.0 has quite the intermittant idle recently. It should be around 900 from what I've read (and it has been in the past) but the past couple days it's been around 2000!

I've noticed that when it starts to do this, if I put it in gear, and bog the entine down a bit by letting out the clutch while standing on the brake, when I take it out of gear, it takes the tach down to about 1500, but that seems still pretty high.

I've been doing some testing on it, and when it's running high, and I turn the throttle linkage counter clockwise, it will drop the idle to it's approproiate level, but as soon as I give it any gas and don't press on the linkage, it will again be back at the 1500 rpm level.

What do you guys think I need to do to get this back to normal? Are the little springs that are around there to blame? Do I need to grease anything up? I'm sorta new at all this, and don't really know how it all works, but I can definately take it apart with some guidance.

Thanks!

Tofer

does it go back down to normal levels when you thump the gas? mines been doing the same thing and i need to figure out whats causing it. i think its due to a dirty TB and dirty TB linkage. but i am not sure. let me know what you find out.

myfinalcoffin

Sometimes, although not always.

I'm planning on tearing it apart tomorrow and seeing what's up. I'll keep you posted.

ovrrdrive

Sounds like a problem with the dash pot to me. Go here and read section 3 to see what I'm talking about.

We used to call this a grannie shift or woman something or another back in the day. It's sole purpose in life is to hold the engine rpm up during a shift to make it easier to shift smoothly...

edit. Just saw you have the v6. This is the correct page for that.

http://personal.utulsa.edu/~nathan-b...93throttle.pdf

ReneB64

does it do any good to clean the filter on the dashpot?

mr toytech

i have also seen the bushings for the throttle plate go bad. if u spray the outside of the throttle body w/ some carb. cleaner and the idle goes up thats probably the prob. u can also try to move the shaft up and down by hand. if the shaft has any play it might be time for a naw throttle body.

ReneB64

I think it is the Dash Pot, I have this problem, exactly the same, thump on gas, it goes down, press gas, goes back up stuck at 1500 rpm. I understand this is a common problem, my mechanic knew all about it, he blew something out with air and it was ok for a while. Anyone know more?

myfinalcoffin

Just to let everyone know, I pulled off the air hose leading into the throttle body, and cleaned it out as best I could without removing it. I was sure to hit the joints where the butterfly valve swings with a toothbrush, and scrubbed the rest with a bottle brush and rags. It works like a charm now.