classic problem with reving RPM's

Post by **tridents65** » 07 Mar 2013, 16:24

1995 non turbo 850. At idle the RPMs are going up and down. Wait long enough and it will die. White smoke (more than normal; 163,000 mi.) from tailpipe and black carbon on the drive from the tailpipe. Check engine light is on. Put the scan tool on it and it says, "P0103 Mass or volume air flow circuit high input". I took off the MAF and cleaned it with correct cleaner. Put it back on and same thing. When I unplug it the car runs better, not such large swings up and down, but still ruff. Afraid to take it out on the road to do any further testing. I had an other MAF sensor that I pulled from a car at the local salvage yard. Cleaned it. same results. I'm thinking I should check the fuel relay next and fuel pressure at the log, but would that cause the rich fuel mixture (black soot)? I will jump the fuel relay to check it. How about the Idle air control valve? Any way to test it or am I heading down the wrong path? One last question. I was going to use a multi tester on the MAS sensor but not sure how. There are four pins. What goes where? Thanks in advance. Reading all I can on the old post and watching U-tube. Read about the engine coolant temp sensor. Not sure. Looked at vacuum lines hard to find them but the ones I could looked ok. Have not sprayed any with starter fluid. Got to get this car back on the road. It's my daughters car and right now she is driving mine. Scarry thoughts!

Post by **Ozark Lee** » 07 Mar 2013, 17:04

Everything you posted still points to a problem with the MAF sensor. What exactly did you clean them with and did you, in any way, come into contact with the sensors?

Is the junk yard MAF an OEM?

...Lee

Post by **tridents65** » 07 Mar 2013, 18:14

I used CRC Mass Air Flow sensor cleaner. Did not touch the sensor. I'm going to have to figure out how to use the multi tester. Maybe even get out the shop manual.

echase76 · Post by **echase76** » 08 Mar 2013, 10:42

I second Ozark Lee. If you got the MAF code and pulling the plug helped it is probably the MAF.

I cleaned my MAF twice and it did nothing. The only thing that fixed it was a used (OEM) MAF that was known to be working.

IAC is easy to clean. You can find a couple good threads out there. Not a bad thing to do with that mileage, but don't expect it to help much.

Post by **tridents65** » 08 Mar 2013, 14:46

checking on a known good one to try. If it solves the problem I will still buy a new one. Have someone coming over this week end to show me how to use the muti tester as I haven't a clue. Looked at the manual I have and it tells me to check the wiring diagram. Also something I do not understand. Will post when I know more.

Post by **tridents65** » 09 Mar 2013, 13:59

Have not had the chance to test anything yet. Last night I cleaned the IAC ( was a little dirty; inside "rolled easyly after cleaning), cleaned the throttle body (it was not really dirty as I had cleaned this not that many miles ago) Checked the vaccume lines one last time and were ok. This morning I put it all back together, got set up with the multimeter and... no start. Had a problem with this car awhile back and could not get it to start. Someone suggested that I put a little oil in each cyclinder in case the coating on the cyclinder walls had washed off from trying to start it and maybe a problem with loss of compression. That worked last time so I tried it again. No start. If I put the peddle to the floor and not pump it, eventualy the motor will almost run but then quits. I'm charging the battery right now for round two. any suggestions?

Post by **tridents65** » 09 Mar 2013, 14:03

If it makes any difference, I had the battery unhooked during the cleaning/ re install.

Post by **tridents65** » 09 Mar 2013, 18:38

since I had cleaned the IAC I checked it out with the multimeter. It is with in specs so it would seam to be ok. I don't know why cleaning the throttle body would have changed anything. Letting the car sit tonight and trying again tomorrow. If it wont start up I' thinking I will pull about 3 spart pluge and squirt a LITTLE gas in the cylinders. whatever, grasping for straws, got to do something.

Post by **tridents65** » 10 Mar 2013, 12:30

I have thrown in the towel. Nothing seems to get this car going again. I put some starting fluid in three of the cyclinders to see if it would fire. No. I had a spare CMP so put that on. No. Rechecked the vaccum hoses. Nothing. I going to have the car towed to the dealer tomorrow. I'm a little dissapointed in myself that I have let my daughter down. Dad may not be the hero she thought he was. I can't figure out what I did that would have caused this. I will post once the car is running to let anyone interested know what the problem is.

ChaddGostas · Post by **ChaddGostas** » 10 Mar 2013, 18:06

I read in these blogs that replacing the mass air flow sensor and the throttle position sensor was almost mandatory.
Make sure you re-learn the computer.
-disconnect -battery terminal for 10 minutes and then press the brakes a couple times to completely drain it.
-drive it easy (grampa style) make sure it shifts through all the gears by the time it hits 25 mph.
take a can of sea foam and disconnect a vacuum line off the front of the vacuum tree and suck about half the can through it.
pour some sea foam down the tube off the air intake box down into the air pump.
make sure the car is running while you do the sea foam.

this helped all the thick smoke from my car, improved gas mileage, and increased power and compression.
I had the same idle fluctuations now they are gone.