map sensor readings?

[Case 7230]

Originally Posted by crabtruck

Round of applause please for Case,
bringing Truth to America ! :applaud:

Many brains makes this a better place.
Next time I'm bringing mine too.

Thank you Sir. However just lucky that I was able to retreive that from the scrambled hard drive that is my brain.
As for the idle problem maybe you should take the Idle Air Control valve off the throttle body and clean it with some carb cleaner.
It may also be worth checking for any stored trouble codes. You can do this using the check engine light blinks if you don`t have a code reader.

[Case 7230]

Originally Posted by cburcham73

thanks guys. i went up and bought a map sensor and it runs alot better.part 2 of the gremlins deals with my idle.with all my acceseries on ac,lights etc when i rev it up and release it falls to about 600rpms and my volt gauge drops then rpms pick back up to normal.it only does it with everyting on...turn them off and it revs and returns normal.

Might also want to lift the belt off and check all pulleys for roughness when turned and for end play, especially idler and water pump pulleys.

[hotrodpc]

Maybe a stronger battery can compensate for all your toys on. If I understand what you are saying, with all the toys on, you are getting a voltage drop, enough thats its affecting your readings on the MAP sensor? I am thinking maybe with a stronger battery, it may have enough power to compesate the drop while idiling, then the alternator can catch it back up when your above idle. Or am I misunderstanding???

You know that last time I told a guy its sounds like his MAP sensor was going bad, he went out and bought a New GPS, then called me and told me his truck was doing the same thing after he installed it, and wanted to know what else could be wrong.

[cburcham73]

i was thinking about a pulley dragging. i'll try that. as for the battery thats new. but i do need to do the 3g upgrade. with everything on at night at a stoplight in gear i can watch my volts drop slowely.tap the gas it goes right back up.... will a bad battery make the truck drop rpm like that? i cleaned the throttle body,and iac is new.

[cburcham73]

ok ... found some weird s**t. i pulled one code yesterday code 122. tps dropped below minium.i warmed it up after idleing for about 15 min. . i had .85 at idle but was jumping around. this morning i checked it i got 1.o v at idle.after running again for about 15 min the engine rev up and cel came on.i checked and codes 122 was there. check the tps and now i have .003 at idle and .004 wot......wtf.....the tps is only 2 months old.

[Case 7230]

Not an expert but sounds like a wiring fault. Clean the plug connections, inspect the condition of the wires and make sure any grounds are tight.

[cburcham73]

i hope its not a wiring fault. the wires look good and i still have my 5volt vref.