91 Stealth R/T Acceleration Problem - HELP!

Check the compression, and also get a leak down test (not the same thing). This will identify if you have any leaking valves. For a 91, could also be worn rings and / or valve stem seals. If you let the engine idle for at least 5 minutes, does it start to smoke? If so it rings. Does it blow smoke when you accelerate (look in the at night: you'll see smoke illuminated by following headlights): valve stem seals.

When you open the gas tank CAREFULLY, do you get a hissing sound (normal), if no or very little hiss sound, then there's maybe a leak somewhere in the recirculate hose circuit.

How about the cam timing? Its not uncommon for a belt to jump a tooth. How about ignition timing?

There's not that many hoses that contain vacuum. Take them off one at a time and inspect each for pinholes.

Stewart DIBBS

Also, check if the ECU is producing any kind of error code. The check engine light won't necessarily come on. Could also be some poor connections on the various engine sensors.

Stewart DIBBS

Only leaks while running.My mechanic narrowed it down to the water pump area, but says it's impossible to be sure whats wrong without tearing into it. No way to see. Is it a common problem with these. If so is it normally O rings or a pump problem or corrosion. Generally what cost are we talking here? thanks for any help or advice. Buck

Thanks for the ideas -

No smoke - but I'll check on the other items. Appreciate the help!

Tim

There is an O-ring on the back of the water pump. It's going to a metal tube that carries water to the back of the block.

How many miles on your '93? Did you have the water pump changed when the timing belt was changed?

Also check

for the Mitsubishi forums. A lot of good Montero/Pajero/Raider/Shogun owners there.

Check the O2 sensors. The ECU may have set a code already

Try looking at

and

MG: thanks for replying Montero has 108k ....Unsure 'bout timing belt.. Shop says 5 beans just to tear it down. Hate to pay that and find out it's more serious. (crack etc.) B

Has it ever over heated?

If not, and you don't know if/when the water pump was replaced, I'd get the water pump done. I did the water pump/timing belt on my '90 a few months ago. It wasn't too difficult. Just take your time.

When you do the water pump also get: timing belt changed crank bolt replaced hoses changed belts changed check the fan clutch maybe have the radiator rodded out

Mitsubishi re-designed the crank bolt. Get the new design bolt it's only about $8. It's a lot, lot cheaper than having the old style bolt break.

thanks mark........will let you know.