I posted here in Honda
because there is no section for an Isuzu. I have an 1999 Amigo which is the same as the Honda
Passport. The problem I am having is this:
I just purchased this car with a friend and a little project. I have managed to make all of the repairs except for this. The car idles rough and is very short on power. When it is at an idle and you floor it (in neutral) it seems somewhat starved for fuel. It revs up very slowly. The best thing I can compare it to is an old carbureted engine with a bad accelerator pump. I also had a check engine light when I first got the car indicating multiple misfires. When I reset the light, it has not come back on. I have driven about 200 miles and it is still off.
So far I have checked the compression. It is 120-/+ in all 6 cylinders.
Fuel pressure is about 40lbs at an idle and if I accelerate it drops. While at an idle, I remove the vacuum line from the regulator and there is no change in pressure. If I pinch off the return line the pressure jumps dramatically. After changing the pressure regulator there is no difference. Since the pressure jumps I am assuming the fuel pump is good. The filter is new.
The plugs are all good.
Injectors were removed and checked. All have good flow and are clean.
I removed the EGR valve
and it appears to be closing and sealing.
My next thought is the coils. They are a little bit pricey and I would like to be sure before I do this. Is there any way to test them?
Thanks in advance.