Stuttering Problems

[mussa]

Hello, i have a problem with my 1995 Nissan Maxima. Recently my crankshaft pulley (harmonic balancer) messed up and i replaced it, a long with the two belts that tore up. I've also replaced the crankshaft sensor thats right there next to the pulley.

Now, when i have my car in park everything is fine, but as soon as i put it in drive the RPM gauge starts fluctuating and the car shakes (like really bad misfiring). Also when i accelerate the car stutters, sort of like if you have a manual transmission and you shift up. I asked a local mechanic here and he mentioned something about some air flow sensor that needs to be "adjusted" whenever the crankshaft pulley is replaced. I've tried to find out if such a thing exists and where, and dont have a clue but it does make sense for the problem i'm having. It also seems like im idling really low as well.

Also, i've noticed once i get above 3000 RPM it wont stutter. But when im driving normal on the interstate at around 2000 RPM, the car stutters really bad. Also the problem gets worse with the AC on.

I've tried searcing through the forums for any similar problems but not very successful. Thanks in advance for anyone that can provide any sort of hint or point me in the right direction .

[Beancooker]

When you say it "messed up" did the pully come off while you were driving? Our engines are rather bulletproof, but if you lost the HarBal while at a decent RPM it may be the timing chain.

[mussa]

well one night as i was driving home from work my AC stopped working and i didnt think too much about it and got home and parked. Next morning i was driving back to work and right before i got to work as i was pulling into the parking lot my power steering stopped. Well as i looked into the hood my belts were missing. After some further investigation, i noticed the crankshaft wasnt aligned with the rest of the "pulley system"... it appeared to have been pushed in about two inches. After pulling the pulley off, it fell into two pieces. So to answer your question it didn't come off while driving, but it also wasnt in very good shape. The car is at 234,000 miles right now.

[Beancooker]

Timing chains are not usually needed to be replaced on our cars, but with your mileage and the problem you had, I'd have a mechanic check the timing at low, mid and high RPM. You may need tensioners or broke a tooth or two.