No power

[Merg]

Good morning! So I just purchased a 1992 power ram 50 4x4 and am having some issues. The truck starts and runs and idles fine after warming up but has very little power. It will backfire a little bit and when you push the throttle down, it just feels like there’s nothing there. It will eventually get up to speed and drive fine but I know it should have more power. At first I was thinking idle air control valve but after a little digging, it doesn’t seem like these trucks have one. Could this be a vacuum issue?

the previous owner said that he put a new head on it and replaced a bunch of sensors. He said it ran perfectly for about 8 months and then it started doing the backfiring and feeling like no power. If you feather the throttle, it will drive but if you try to get into it to accelerate to get into traffic, it’s got almost nothing.

I am a Yamaha outboard tech and am pretty familiar with engines in general but I wanted to ask some of y’all before I just started buying parts to throw at it. Any help at all would be much appreciated.

thanks!

UPDATE!! It’s fixed! So it was a combination of a few things that was causing all of the intake backfire and no power issues. First, I removed all of the emissions parts. Vacuum lines, charcoal canister, EGR and capped everything. Which made the rich running condition stop. Then, I used my timing light to find that the ignition timing was firing before the intake valve could completely shut, causing the fuel mixture to detonate allowing the combustion to push back into the intake manifold. So I loosened the 12mm bolt holding the distributor and rotated to the highest rpm I could get and then adjusted the idle back down. She’s running like a champ now. No more popping and normal acceleration power.

[MISTEREAPYA]

UPDATE!! It’s fixed! So it was a combination of a few things that was causing all of the intake backfire and no power issues. First, I removed all of the emissions parts. Vacuum lines, charcoal canister, EGR and capped everything. Which made the rich running condition stop. Then, I used my timing light to find that the ignition timing was firing before the intake valve could completely shut, causing the fuel mixture to detonate allowing the combustion to push back into the intake manifold. So I loosened the 12mm bolt holding the distributor and rotated to the highest rpm I could get and then adjusted the idle back down. She’s running like a champ now. No more popping and normal acceleration power.

If you don’t mind me asking, Might sound a little silly but when you said you capped off the emissions, what and what was it exactly you capped off.. My has no power either and checked everything like you had first.. thanks in advance..