My Jimmy runs well on flat roads, however, when I try and drive it up a steep hill, it will stay at 3000 RPM, lose power,sputter and stall. If I stop and turn around the car will eventually stop sputtering, and drive fine again.

Was previously getting an engine misfire code, on highway, only upon acceleration, had transmission rebuilt, replaced catalytic converter, o2 sensor, MAP,MAF, Fuel filter, distributor, radiator, intake manifold gasket, spark plugs and wires, and now no codes but still cannot get up that hill!

Have had suggestions that it may be the timing chain, torque converter or fuel pump.

What should I try next?

How much gas in the gas tank?
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.

Also tape a fuel gauge to outside of windshield and watch the fuel pressure when it acts up.

Thanks for the reply.

Starts fine cold.
This happens irregardless of how much fuel is in the tank, but only happens on a steep incline.

Have had fuel pressue at idle and fuel injectors tested - fine.

Had the P0300 code, and replaced all parts above. Now, no check engine light but shutter and stall on steep incline, and miss at high speeds on highway.

Sucking fuel like crazy....


what next?

Thanks for the reply.

Starts fine cold.
This happens irregardless of how much fuel is in the tank, but only happens on a steep incline.

Have had fuel pressue at idle and fuel injectors tested - fine.

Had the P0300 code, and replaced all parts above. Now, no check engine light but shutter and stall on steep incline, and miss at high speeds on highway.

Sucking fuel like crazy....


what next?

Next is we need you fuel pressure readings.

Put the fuel gauge on it and see what the fuel pressure is on the hill.
If it holds good fuel pressure on the hill move on the ign and pcm sensors readings.