ATA_Spiffy

I have a weird problem with my truck. When it warms up sometimes the idle changes. It might stay solid at 750rpm for 30 minutes or so no problem. Later it might change to 950-1000rpm for no apparent reason. Both cases the truck has been warmed up to operating temperature before changes so I have ruled out temperature effecting it. Another key detail is when I apply the brakes the idle will drop sometimes. If I let off the brakes standing still in neutral the idle goes back up. If I apply the brakes again it goes back down. It doesn't always do this though and I have been trying to figure it out for months.

I tried running the tests I have read about on here for the tps but my manual says the readings should be similar for later model trucks but doesn't give me an actual number for after say 89' model. Does anyone know what resistance and opening gap to check the 94' to. I am a little bit suspicious of the tps.

I have what seems to me a little but too rough of an idle. Not missing really but it feels like it has a lope at idle instead of completely smooth. Fresh re-manufactured engine with RV cam.

Another thing I have noticed is when rolling very slow in first and the throttle is very gradually applied the engine revs increase smooth and then at maybe 1/8 throttle rpms drop suddenly then rev back up and basicly continues jumping at this throttle opening until either more or less throttle is applied. It can be really annoying trying to drive in traffic.

I'm curious if whatever is causing everything might fix the lack of power it seems to have. For a fresh engine it doesn't seem to pull quite as hard as I think it should. Understanding it is only a 2.4L .


A side note, Has anyone tried hood scoop induction on their truck. I have thought a scoop could really improve performance on the interstate I think at higher speeds you could get the boost of a mild turbo/blower.


Thanks for your help, I enjoy reading these forums.
Spiffy

Chapman88SR5

Read here for the TPS and basically anything else.