Help with an acceleration issue.88 740 gle no turbo
 

I recently have installed new fuel pressure regulator,both fuel pumps,fuel filter,harmonic balancer,cleaned the throttle body,and the idle control valve.now it only starts up if have the maf sensor unplugged and the second I plug it in it stalls the motor.or if I touch the accelerator.

Well, may be the MAFS is bad?

yeah, if it runs (poorly) in limp mode without the MAF but won't run at all with it, thats a pretty good sign of a fried MAF.

Help me help me
 

It has a new one on it.could it possibly be something in the electrical,I mean it just recently started letting me roll down the windows with the key off so is it safe to assume that it's gotta short somewhere

whenever you do a bunch of things to a car the question is whether the new parts were of a. good quality, b. installed correctly. what kind of mafs did you put in? many cheap asian parts today are available and they work badly in volvos; not all, but some things like mafs are crucial.

the windows working without the key suggests a bad ignition switch, or the power window relay is stuck in the closed (on) position. do other things that should turn off with the key stay on, like the headlights ?

and yeah, I second the emotion, 'new' parts aren't necessarily good parts. only way you can know for sure is to swap the part with a working car, and if THAT car stops working right, and your car now works, you know your part is bad, swap the good one back and get a different replacement.

What is the voltage at the battery when the car is running? Charging system is usually overlooked. I like the bad ignition switch idea as well.

Anywhere between 13.5V to 14.2V is acceptable and says the alt/reg are working correctly

Help me help me
 

Well when I remove the relay a d check the terminals,I have instead of just one hot lead I now have two,and as far as the maf sensor goes the original one I replaced did the same thing that this new one is doing so im even more frustrated confused.Now I went ahead and replaced the suppression relay and I was able to start it up it ran for about 30 seconds and then It just stalled ,but I still don't understand why the minute I touch the accelerator it stalls

Was the fuel pump relay checked? You might have enough fuel to start but not to move the throttle. Mine sat for a long time. Starter died while trying to start the car. Everything you have done was done to the car by PO. I tapped the fuel injectors with a tack hammer and she started up fine. Took about 5 minutes and she idles and moves fine. Could be clogged injectors.

Your issue COULD be electrical. In the book I imagine there are some trouble shooting tips to determine if MAF is bad. I just looked at www.RockAuto.com and that MAF ain't cheap either. Did you replace the air filter? Might be too clogged to pull enough air. The you pull the MAF lead and force it to bypass the MAF and pull through filter.

Spit-balling ideas..