Loses power

93/94 Rodeo, manual trans. 3.2 L. I have been having a problem with my Rodeo for several years and no one has been able to fix it. It is now worse than ever.
When I step on the gas to accelerate, the engine does not accelerate and will actually decelerate. This occurs especially under load. Barely goes up hills in any gear. At idle there is no problem and I can rev the engine with no problems. At some points while driving the engine will act normal for a very short period of time and revert right back to bogging down. NO CHECK ENGINE LITE COMES ON.
I have replaced the O2 Censor, timing belt, water pump, clutch, plugs, wires, starter, alternator and just about every other part on this vehicle. Im lost. Someone please help.
Thanks[/b]

Have you tried to check the pressure at the fuel rail? So you can check if the fuel pump is working. Also, have you replaced the fuel filter?

This guide can help

https://www.2carpros.com/articles/engine-has-low-power-output

Please run down this guide and report back.

Thank you for the guide! I had a clogged air filter cost me $14.00 all fixed I love this site.

I have a 1990 Isuzu Trooper 2.8 L V-6 139000 miles

We have now replaced the fuel injectors on the throttlebody, all of the sensors, since replacing the injectors the vehicle still hesitates at acceleration, it hesitates or stalls during take off occasionally it hesitates when changing gears In order to avoid cutting off in the middle of the road the only solution is to flutter the gas pedal during take off. What should we check next?

I was having the same probem with my trooper. Even I after I had the engine and the transmission replaced. I was driving at 65 mph and my muffler exploted plus my catalytic converter burned. I replaced them and still I had the same problem. It is in the shop right now. I was told that the problem might be the computer or the fuel sensors. They are going to test them. I'm begining to think that if it is none of those than the fuel pump is the problem.
I'll keep you posted if you are interested.

Casti1

I have a 1990 isuzu spacecab pickup 2.6l 4x4 5spd. Manual transmission. Rough idle sometimes wont stay running sluggish, loss of power. Massive gas usage. Changed plugs, fuel pump, filter screens on pump, vaccum lines still no change any thoughts?

This sounds as if the computer is being told the engine is very cold. The computer gets the coolant temp from a separate sensor than the guage or light. If the sensor fails or you have an open circut, (broken wire) the computer adds fuel as if it is -40 degrees F. Find the sensor and check it. Other wise you might have the same problem with MAP sensor. 8)

I have a '92 2.6L 4cyl 5spd Isuzu Spacecab with the same symptoms noted below. Through a two day series of inspections by my mechanic, it was found that there was a vacuum leak on the number 4 intake runner. The O2 sensor was malfunctioning, and truck was consuming gas similar to an 8 cylinder. In addition, the thermostat was also faulty. There was often no power, very sluggish, and often stalled out. The problem was diagnosed with a smoke test. The required repairs have led to the indefinite parking of this truck.

My car has no power. Ithe positive side to the battery was completely coroded. I cleaned it and it appears that there was a cable connected but now it isnt. The part that looks like it was connected is like a little plastic rectangular piece. My question is: Is that cable most likely the reason it has no power and is it easy to replace?

Jade

The cable you referred to is the power cable for the truck and needs to be hooked up for the vehicle to operate. It should be hooked up with the quick release so when doing electrical work it can be disconnected so as not to cause a surge to the computer (ECM).

Fred