Replaced the Coolant Temp sensor at the advice of you guys a few months back, and it has been working nearly perfectly since then until a few weeks ago it started to intermittently lose power and smoke black while driving.

It's gotten progressively worse in the past few days, I checked all the sensor connections, like MAFS, and all that, nothing is loose, and it doesnt always do it.

Im thinking 02 sensor, but it's a little pricey to just toss one in and hope for the best. What will a bad 02 sensor do on one of these cars? It loads up off idle, but idles okay, no power and it seems get real bad, then be okay again, then worse, then okay.

I pulled the injector pigtails 1 by 1 and it didnt change anything (still smoked when revved) so I dont think it's an injector problem, and it runs so good at WOT sometimes I feel I can rule out the cat...

help?

also..started blowing the Power Window/Heated seats/blinker fuse last week, went as high as a 30A fuse and it pops as soon as the ign. is turned to run..so It's a short, any hints one where to start looking, like a common trouble spot?

 

1) Try replacing the air filter. I had the same problem and that cured it.

2) The easiest place to look is right at the switches. Could be crossed wires somewhere there or hot wire to ground.

 

I agree with teh filter. Also, check all your intake hoses after the MAF for leaks etc.
Another culprit could be the fuel pressure regulator.

Regards, Andrew.

 

Air filter is fairly new and clean, I pulled it and checked it anyways, looks amost new..car runs rich without it however.

Checked all turbo pipes before the turbo, no signs of a problem, Ive made a few repairs to the MAFS/TURBO pipe, still looks good.

FPR doesnt smell of fuel and no fuel in the hose, hose is also not spongy.

Its sets a code every so often, last I checked it said 02 sensor, but I was told by a Volvo tech it is most likely a result of the problem, not the cause.

 

Car has been deemed unsafe to drive, sooo rich, sooo much black smoke it isnt even able to go 25mph.

I pulled all the turbo hoses and found a small puncture in the MAFS to TC elbow, picked up a new one @ 79.95 OEM Volvo part, but no change after the install.

How can I test the MAFS and o2 Sensor?

 

I typed into google how to test an o2 sensor and I got some hits. It looks like their is some youtube video as well. That might be a place to look. This is something I want to learn myself -- learn how to test different sensors because it does get expensive throwing parts at a car when your not certain its the cause.

 

Due to the Volvo being out of order, we were using my truck to get back and forth to work, get parts for the volvo, etc...1998 Ram 1500, 206K miles on it...

Well after work on Thursday the Trans went out in the truck and I just barely made it home.

I couldnt get to work Friday, no ride..but I was able to get a ride ot the parts store to get the 02 sensor, got it pu on, and while the car does run a little better in terms of stalling when you lift off the pedal, it still smokes black.

SO...I went to the MAFS and unplugged it. The cars started fine, and while I couldnt drive it because it kept stalling, I was able to rev it cleanly with no smoke as long as I didnt move too quickly...

So a MAFS is coming, should be able to pick it up on Mon or Tuesday.

I also removed the CAT, it is very very sooty and dirty inside, It isnt blocked, Im hoping I can use compressed air to blow it out, and hope a well tuned good running car can burn it clean?

Car sounds awesome though..haha

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I got my project vehicle, a 1989 Jeep Grand Wagoneer driveable for the time being, as i cant afford a 1000 dollar used trans for the Truck, and the Volvo wont have the MAFS until probably tuesday.

If I dont see myself getting the truck back going within a couple weeks Ive got a 1985 Corvette I can get back on the road easy enough, just needs rear tires and a battery, was driving it daily until we got the Volvo done being restored middle 2008.

 

Yeah, a good long climb up a steep hill will clean teh cat out nicely, no problems there. Hope you have the problem sorted out soon, sounds like you are on top of it!

Regards, Andrew.