surging at low rpm

[prich]

my dads 1991 5 speed experiances surging at low RPMs mostly in fourth and fifth gear

 

[Greenleaf]

Does it do it when he is lightly applying throttle, lightly decelerating, or trying his best to hold it steady?



Have you or him checked the throttle rod (ball) joints?



Have there been any other symptoms?

ie power loss, loss of top end, lower operating speeds, etc. ??



Has he found it necessary to change the way he starts the engine?



Has it had good preventative maint. and if so what?



Have you guys changed any of the pumps settings?



Change any parts at all?



-S

 

[prich]

nothing has changed as far as starting or power. the only thing I have done is added a spring for more tension. My truck seems to have no end to the RPMs. This truck (dad's) seems to be governed.

 

[Greenleaf]

I'm trying to help but, you need to answer some more of the questions.....



Providing everything outside the pump is OK.....

you may want to look at lift pump pressure or more importantly the inners of the pump. Gov settings.

You every try turning the pump up a bit? Maybe all it needs is some injector cleaner????????



I'd take a real long, close look-see at all the linkages, especially the pump's fuel control lever assembly first before condemning the pump's gov. or other internals.



You could take a quick look inside by removing the shut-off solenoid.



It could also be something like the rear diff bearings are going out too. This will give the vehicle a "funny feeling" while driving down the straight and narrow.



-S