I have been told that throttle body engines have a quiver and tend to run lean. Has anyone with a throttle body noticed there truck not idling smooth because of this? My old engine did not do this quiver but it may be an excuse to not get the idle right by the mechanic. Wanted an opinion or experiences from people with tbi trucks.

 

Mine used to shimmy a bit when stock but a good tune flattened out the idle good.

 

What year was your truck? When you say tune do you mean using a programmer?

 

TBI trucks tend to "quiver" slightly at idle....it has something to do with the fuel puddling in the intake manifold, believe it or not a TB-spacer will sometimes help mellow out the quiver (it increases plenum volumn enough that the feul will stay atomized in the manifold longer)

 

Truck in my sig!
And tune as in Dyno tuned. Programmers are a waste of $$.

 

As Yelo mentioned, a spacer can help... but, there are actually TWO spacers that can help performance-wise. One that goes under the TBI unit between the manifold and the TB, and another that goes in between the injectors and the TBI housing. Each are worth some performance gain, but neither smooth out the idle in my experience.

The idle issues I've encountered with TBI units have all been from worn throttle shafts. There are a few people on EBay that used to fix/repair them with new bushings or bearings...

 

My 94 TBI truck, always had a "fish bite" as it is called around here. I tried everything to get rid of it, even replaced head gaskets b/c I thought they were blown( from the 150 shot), even the day I got rid of it , still had your quiver....

 

check into a ajustalble fuel pressure regulater combined with t-body spacer really helped a 95 tahoe i was working on. stock fuel press to low to let fuel atomize correctly

 

Is there any way to measure the fuel/air ratio on a 91 truck? To see what it is running.