740 GL 1989 Acceleration problems

[msackmann]

Hi all, wondering if anyone has any ideas about what might be wrong with my car. Car starts fine and idles great, but when put in drive the car will barely accelerate. And the RPMs barely creep over 1.5. I have changed the ATF, and checked the gear selector. Cleaned the MAF with MAF cleaner. All these didn't help. I am thinking maybe its the MAF because when i unhook it from the air filter, the car accelerates much better (but will not shift). I also unhooked just the electric plug from it and car stalled immediately when in drive. So maybe the MAF is broken and not just dirty? I also cleaned the throttle body yesterday but haven't put it back on. I have not checked for vacuum leaks yet, which is a possibility. Could the timing be bad? I originally thought it was transmission problems, but now I'm thinking its something else. Any help would be greatly appreciated.

thanks,
matt

[billofdurham]

Welcome to Matthew's Volvo Site.

There is mounting evidence that a dirty MAF sensor can cause gearbox malfunctions, such as reported incorrect ratio errors, loss of 4th gear or torque converter clutch (TCC) operation, even on gearboxes recently overhauled at great expense. When you unplugged the MAF the car would drop into limp home mode thus eliminating some of the gear changes.

As you have cleaned the MAF without success it seems that a replacement is called for.

Having cleaned the throttle body you may notice a rise in the idle speed. This can be remedied quite easily.

Bill.

[msackmann]

Thanks, Bill for your respoonse. It actually was the throttle body. When I hooked it up after cleaning it she ran like new. Well...more like a 20 year old car, but good enough for me.
Thanks again,
matt

[billofdurham]

Thank you for the update.

20 year old cars are often less bother than 20 day old things and easier to work on!!!

Bill.