Losing power

COOLDOGG

MEMBER
1996 ISUZU TROOPER
3.2L
6 CYL
4WD
AUTOMATIC
320,000 MILES

I had transmission problems got it fixed. Now I have a slightly rough idle, but what is concerning is while I’m driving it seems I’m losing power. I can put it to the floor it doesn’t change but if I let off a little bit it will get the power back then lose it. Please help me to fix the issues. This is my only car I drive around 10 to 15 miles one way to work 6 days a week I don’t want to be stranded. Help

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,336 POSTS

Welcome to 2CarPros.

The first thing that comes to mind is a weak fuel pump. If you open throttle (wide open) you are allowing a lot more air to enter the combustion chamber. If there isn't enough fuel pressure to provide the needed fuel, what you described will happen.

To confirm that is the problem, we need to check fuel pump pressure. Here is a link that shows in general how it is done. You will need a fuel pressure gauge, but most parts stores will lend or rent one to you.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the manufacturer's specs for pressure:

1996 Isuzu Truck Trooper V6-3165cc 3.2L SOHC (6VD1)
Fuel Pressure
Vehicle Power-train Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Specifications Pressure, Vacuum and Temperature Fuel Pressure
FUEL PRESSURE
Note: Test should be performed with the Key On and Engine Off. Readings should be taken after two minutes have elapsed from the time the ignition was turned On.

Fuel Pressure .................... 333 kPa (48 psi) to 376 kPa (55 psi)

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Please keep in mind, I am going from your description and this is the most common cause. It could be other things such as an engine vacuum leak, plugged catalytic converter, or even a partially plugged fuel filter. However, we need somewhere to start.

Let me know what you find or if you have other questions.

Take care,
Joe