JBC2005 Posted July 10, 2007 Report Share Posted July 10, 2007 After ALL LOT of fooling around with easy-outs, I finally got the broken plug out! YAY! Now, I have a new problem: Car will not idle. I start it, and unless I press on the gas, it stalls. Erratic idle after warm-up. Pulled trouble codes from computer, and the diagnostic tool displays "MAP Sensor or low circuit". Bad MAP sensor or busted vacuum line? If vacuum line, where do I begin tracing? I really need help on this one. My dad wats his truck back ASAP! Thanks Jon 1994 Pontiac Grand Prix 3100 SFI V6 4T60E tranny Quote Link to comment Share on other sites More sharing options...
ns87 Posted July 10, 2007 Report Share Posted July 10, 2007 On my 3.1MPFI it was just a popped off vacuum line. I'm not familiar with the 3100 engine though, sorry Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 10, 2007 Author Report Share Posted July 10, 2007 Where? Which line? Quote Link to comment Share on other sites More sharing options...
ns87 Posted July 10, 2007 Report Share Posted July 10, 2007 Im sorry, I don't know where the MAP sensor is on the 3100. Try using the search feature in the forum to at least locate it. Once you find it, theres only ONE vacuum line coming from it (its hard brittle plastic). If it is broken, read my post here for how to repair a vaccuum line http://www.w-body.com/forum/index.php/topic,61171.msg726378.html#msg726378 Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 10, 2007 Author Report Share Posted July 10, 2007 Tried three different MAP sensors and two vacuum lines. No change. Changed ICM/coilpacks, no change. Can hear a hissing coming from the area of the purge valve solenoid. Jon Quote Link to comment Share on other sites More sharing options...
Supreme Cutlass Posted July 10, 2007 Report Share Posted July 10, 2007 Tried three different MAP sensors and two vacuum lines. No change. Changed ICM/coilpacks, no change. Can hear a hissing coming from the area of the purge valve solenoid. Jon lol, then fix the hiss Quote Link to comment Share on other sites More sharing options...
timestalker45 Posted July 10, 2007 Report Share Posted July 10, 2007 um if not that try and use a smoke machine. connect that to ur vacuum line and if theres a leak it will blow out the smokefrom it my mechanice showed me on a customers car. Quote Link to comment Share on other sites More sharing options...
ns87 Posted July 11, 2007 Report Share Posted July 11, 2007 Or take throttle body cleaner and spray different areas on the lines. When your idle goes down, thats where the leak is. Don't spray too much though, otherwise you're car might catch on fire Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 12, 2007 Author Report Share Posted July 12, 2007 Update: Changed vacuum lines for nothing. Hiss was coming from the serpentine belt! DOH! Checked voltage to and from MAP sensor. 4.83 volts reference from the ECM. 0 volts coming from SIGNAL when the engine is running. Bad MAP sensor or blown computer? So close I can taste it! Advice? Thanks Jon Quote Link to comment Share on other sites More sharing options...
timestalker45 Posted July 12, 2007 Report Share Posted July 12, 2007 u try the wire might be the connecting wire. i just found out my car needs a new relay cable from my speed sensor to my ecm, my speedomiter was going up and down tried every thing replaced vehical speed sensor, and ecm finally after weeks of fighting with it i had it tested and thanks to amco turned out its the wire.Age does damage Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 12, 2007 Author Report Share Posted July 12, 2007 I thought about the wire, but I tested for voltage right out of the sensor. I have 4.83 volts going in, and nothing coming out of the sensor. Quote Link to comment Share on other sites More sharing options...
BXX Posted July 12, 2007 Report Share Posted July 12, 2007 Then the sensor is bad I have a good one for sale cheap.... pm me if interested Quote Link to comment Share on other sites More sharing options...
timestalker45 Posted July 12, 2007 Report Share Posted July 12, 2007 that would deff be sebsor if has no out put Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 13, 2007 Author Report Share Posted July 13, 2007 Checked MAP circuit.......bad ground! Replaced MAP sensor. Still no idle. Checked output voltage on SIGNAL line....... 0.02v key on engine off 0.04 - 0.06 @ idle 0.07 - 0.12v @ WOT Bad harness? Still bad ground? Where does the ground go for the sensor? Any ideas? Getting supremely frustrated! Jon Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 13, 2007 Author Report Share Posted July 13, 2007 Any thoughts? Quote Link to comment Share on other sites More sharing options...
ns87 Posted July 13, 2007 Report Share Posted July 13, 2007 I would follow the wire to the ECM. There may be a break in the insulation somewhere. Keep at it, electrical stuff can be tough Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 15, 2007 Author Report Share Posted July 15, 2007 Update: Repaired bad ground from sensor. Sensor functions. No codes. Car starts, and idles. Doesn't stall. At idle, feels like it's missing. Exhaust gases coming from pcv hole in valve cover. Believe because of running without #3 cylinder and MAP sensor, that raw fuel and carbon caused from rich gas has partially plugged cat. Purchased new converter and will swap next weekend. If condition still exists after that, will check injectors. Thanks to everyone who responded with suggestions. Jon Quote Link to comment Share on other sites More sharing options...
ns87 Posted July 16, 2007 Report Share Posted July 16, 2007 Depending on how much money you're looking to spend, I would replace the O2 sensor if it hasn't been replaced. That got rid of a lot of my chugging. I spent ~30 with the sensor and the expensive attachment to remove it. Quote Link to comment Share on other sites More sharing options...
Supreme Cutlass Posted July 16, 2007 Report Share Posted July 16, 2007 Update: Repaired bad ground from sensor. Sensor functions. No codes. Car starts, and idles. Doesn't stall. At idle, feels like it's missing. Exhaust gases coming from pcv hole in valve cover. Believe because of running without #3 cylinder and MAP sensor, that raw fuel and carbon caused from rich gas has partially plugged cat. Purchased new converter and will swap next weekend. If condition still exists after that, will check injectors. Thanks to everyone who responded with suggestions. Jon So are the gases from the exhaust system or the pcv valve hole? Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 16, 2007 Author Report Share Posted July 16, 2007 If I remove the pcv valve with the engine running, exhaust comes out the pcv hole. I think it's because the converter's clogged. Jon Quote Link to comment Share on other sites More sharing options...
JBC2005 Posted July 18, 2007 Author Report Share Posted July 18, 2007 Another thing I noticed today, at speeds over 80 KPH (after OD kicks in), the car stumbles a bit. It's fine after it downshifts back into 4th gear. Could a clogged cat be causing this? Possible O2 sensor failure? Any suggestions? Thanks Jon Quote Link to comment Share on other sites More sharing options...
IRONDOG442 Posted July 18, 2007 Report Share Posted July 18, 2007 If I remove the pcv valve with the engine running, exhaust comes out the pcv hole. I think it's because the converter's clogged. Jon Exhaust cannot be comming from the PCV valve, unless you have some serious internal engine problems. Quote Link to comment Share on other sites More sharing options...
Supreme Cutlass Posted July 18, 2007 Report Share Posted July 18, 2007 If I remove the pcv valve with the engine running, exhaust comes out the pcv hole. I think it's because the converter's clogged. Jon Exhaust cannot be comming from the PCV valve, unless you have some serious internal engine problems. exactly, either you have exhaust leaking from behind the engine or it's emission gasses and you need to change your pcv valve. Quote Link to comment Share on other sites More sharing options...
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