Thread: MAF & TPS dead or dirty?

My 01 GTP w/ 104k had been developing issues so I ordered all of the parts and tried to fix everything this weekend. It had the following issues, bad thermostat (stuck open) throwing a code, slight coolant seepage around the LIM no coolant loss, just damp, rear valve cover oil leak. Also is has been giving some trouble starting. I key it over and it spins and spins but won't try to fire at all. If I give it a slight amount of gas with the pedal, it starts right up. Also it has a slight surge at idle as the rpm's vary ever so slightly. I could feel it and the tach would show a 50-100 rpm swing Idles at 900 or so and would swing to 850-950. So I tore into it and replaced everything. Also I figured I would check the throttle body for build-up as a little old lady owned it before me and babied it. I took the TB off and it was solid black so I sprayed a slight amount of TB cleaner in it and scrubbed with a clean terrycloth till the blade and body were clean. I don't think I got any on the MAF sensor but it probably got in the TP sensor. Now I start the car back up to get the air out of the coolant and it idles all over the place from 500 to 1500 having to give it gas to keep it running. Then it smoothed out so I went to keep the radiator topped off as the thermostat opened up and the car just died. It starts right back up and seems to run fine above 2000 rpms but jumps all over the place at idle. I drove the car to the gas station as it was low on fuel to see if it cleaned up at all and had to drive in second gear the whole way home because if the idle dropped too low, it would die. Not much fun on wet curvy roads. So it is throwing 3 codes, 2 showing MAF out of range and 1 for the throttle position sensor. I'm guessing they are screwed up from cleaning the TB but are they dead or do they need cleaned with sensor cleaner? Or did they cause my slight idle issue and they finally died? I really don't want to spend $200 on sensors if an$8 can of cleaner will fix the problem. Any ideas or help????

Try cleaning the MAF with approved MAF cleaner and see what you get. If that doesn't help try disconnecting the MAF and then start the car. You may need to help it stay running for a minute but it should eventually run on its own. If it idles fine and runs better then I suspect the MAF is shot.

Your TPS is probably bad. Just replace it. Also may want to look at the IAC valve. Also, check for any vacuum leaks around all lines and the LIM/injectors. The vacuum T under the SC snout like to rot and crack resulting in a nice leak there as well. Also check the accordian looking EGR tube as they will often break in the little creases and not be easily visable.

After driving it, it was idleing smoothly but at 1500 rpms so I expect it switched to default settings. I thought maybe I plugged them into the wrong locations but they are keyed so they will only go in the correct sensors. I hate to think it fried all three senors and valves in the throttle body from cleaning it. I figured the IAC was causing the idle surge but now I don't know. Also where do I get a bit to take out the security torx screws holding these things in place?

Also I checked all the vacuum lines as I took them off for the LIM gasket swap as my last GTP had serious vacuum issues and they were still soft and no checks or cracks. I didn't look closely at the egr tube but I was careful in sliding it out of the way and back in with minimal movement and flex.

dude i have an 04 gt with the supercharger and it did the same **** to me bout 3 weeks ago im still stuck on whats wrong with it changed out the entire electronic throttle body cleaned the maf and changed the broken crank shaft position sensor it had almost exactly the same symptoms of yours having to keep it above 2k to keep it alive but now mine has gotten to the point where i cant even start it with giving it a lil throttle. if u get an answer send me a message

Problem solved. Cleaned the MAF, IAC and TPS and nothing changed. Started checking for vacuum leaks and found a hard plastic line snapped right under the SC snout. It must have snapped when reinstalling it as it was fine before. Replaced it with rubber vacuum line and it runs like it should. Thanks for the suggestions.

Good to hear you got it running good again. Look at it this way, now you know the MAF is clean along w/ the other sensors.

Exactly. Not to mention it starts and idles a lot better. Well worth the $8 for the cleaner.