98 s70 Runs poorly

nickdeary · Post by **nickdeary** » 29 Jun 2011, 08:41

Hi guys,

I have a 98 volvo s70 which runs really badly. I recently replaced the alternator and the starter and in order to loosen the belt I had to remove the PCM, which I removed without disconnecting the battery. The car runs like shit now, but when you disconnect the MAF it runs good enough to drive, so i figured that means new MAF, so I got a new one and when you hook up the new one same problem. This makes me think whatever connects to the MAF is busted. THe other thing is that this car ran great before I replaced the alternator. I think this issue is something wrong with the PCM but I am open to suggestions.

THanks

Nick

Post by **Ozark Lee** » 29 Jun 2011, 12:17

What if any codes is the car posting? Codes go a long way in helping us diagnose your specific problem.

Most chain auto parts stores will either read them for free or "rent" you a scanner so that you can read them yourself. The "rent" works by charging you list price for the scanner and then they will credit your card back 100% when you return the tool.

...Lee

nickdeary · Post by **nickdeary** » 01 Jul 2011, 08:34

Sorry I should have informed you. When the MAF is NOT hooked up i get the MAF malfunctioning code which is obvious. When I have the MAF hooked up the car shows no codes until you get it to stall and then it pulls Turbo Wastegate Code. Let me know if there is anything else I can tell you. I have a strong feeling that between alternator replacement starter replacement and taking out the pCM and everything I have caused this.

Thanks so much!

Post by **jblackburn** » 01 Jul 2011, 08:38

So it's a turbo model then?

My thinking is that there is in fact some turbo air hose or vacuum hose or something that got knocked off somewhere. That it runs without the MAF sensors suggests (doesn't necessarily indicate) that it's not measuring all of the air entering the engine, so that it runs on a best-guess estimate for what's actually there when the sensor isn't plugged in.

If all else fails, yank the negative cable to the battery, drain the charge through the ignition key or brake pedal, and re-connect it.

nickdeary · Post by **nickdeary** » 05 Jul 2011, 06:47

you the man! I found one of my hoses were lose car runs fine now! While I got your attention the final problem on the car is that I believe the rack and pinion is shot because it got hyperextended due to a missing bumper on a control arm. Can I replace the rack myself or do i need to jack up the engine?

THanks