Greetings!

I bought a 92 Dakota 4x4 last year and have recently developed an engine problem. The truck. Under load (above 2500 rpm), the truck sputters and . I have no passing power and limited power to make it up larger inclines. Under 2500 rpm, it drives perfectly. Above 2500rpm, it sputters and occasionally there's a small backfire. There is no CEL. No smoke or funny smells.

Edit: On the way to work today, all of a sudden, it lost all power. I couldn't get above 15 mph. It'd sputter and backfire. Letting off the gas brought it back to a steady idle. Once it stalled on me. I turned off the truck and restarted it. It then drove normally. Maybe my 1 year old PCM is shot?

In park or neutral, it easily gets above 3000rpm

I have not really looked into this yet, waiting for the weekend.

From what I've read, it might be the plenum gaskets? Is this accurate?
Possibly a restricted exhaust?
The fuel pump is new.
Crank sensor and TPS new
Cap, rotor, plugs, fuel filter and PCM 10,000 miles ago
I have new gas in the tank since this started
The truck has 119,000 miles

Any other things I should look into?

Thank you for your help!

 

Plenum is a possibility, can you see oil on the floor of the plenum (intake manifold)? Exhaust restriction goes hand-in-hand with plenum gasket failure, as the oil gets into the combustion cycle it eventually clogs the catalytic convertor.

Looking toward the easier things first, I didn't see on your list if you have checked/replaced your plug wires?

 

No I haven't replaced the plug wires. Coil is also original.

 

Almost sounds like you are running out of fuel. Its hard to point people in the right direction on the forum. Fuel filter in line? or in tank?

 

back when you even had a fuel filter that could be replaced, (now a days carmakers have eliminated them, unfortunately) 10K miles was a good replacement interval. Now a days fuel systems are "returnless" but yours has a return line to the tank. over 1/2 the fuel delivered to the engine gets returned to tank and constantly recirculated til it is burned. I have replaced fuel filters on vehicles just to have them clog in 500 miles before. Not often but it does happen.

on another note; only 119K original miles on a '92? Wow! that is quite low! my last one had 202 on it and I only got rid of it because I wrecked it, badly. My current one is at 181K and still going strong.

 

It ended up being a fuel pump again! I got the last one warranteed since it only lasted 3 months.

Testing fuel pressure with the engine at idle was just fine. Brake torquing for about a minute with the fuel pressure gauge attached showed that the fuel was slowly falling off. It'd start chugging at 10 psi.

Did not change the fuel filter, as the rubber fuel lines are about to break. So, I ordered all new fuel lines.

Yes, very low mileage for a 1992. I bought it with 109,000 miles a year ago. The trans blew in 1999-2000 and it was sitting on a farm. I picked it up for $300 and made it driveable again.

Thanks for all your help!

 

Glad we could help buddy