VTJeep

ok... i really hope someone can shed some light on this one for me... i went to two different parts stores this am and both of them could not find a replacement MAF sensor. there is the ambient air temp sensor, but thats not it.

my issue is irregular throttle response: i only have to be on the throttle the tiniest bit and it will want to rev all the way up to +/- 3k rpm. if you blip the throttle it will hold its revs for a couple of seconds after you let off the throttle. you can hear it sucking a lot of air in when at idle r low throttle.

part of why im stuck in being able to fix it is because it refuses to throw codes. it recently threw a code saying my downstream o2 was sweeping out of range. so i replaced both and the prob went away for a couple of weeks, then it was back. this time the CEL was on and it again said the bank 2 o2 sensor. so another new one was installed, but now the CEL is on for a leak in my evap system. so could this be causing it? i will list all of the parts replaced or checked/cleaned so as to provide a better idea of my efforts... any help is really appreciated!! really anyones .02 would be nice on this one... :/

NEW:
-tps
-iac valve
-plugs/wires
-cap/rotor
-battery cables
-both o2 sensors (the downstream twice...)
CHECKED/CLEANED:
-injectors
-fuel pump filter and gas lines

i feel like i should be very close in eliminating this problem. i think the next step is to check the evap system for leaks. i know my vac lines are iffy cause ive got that issue where the air flow will switch to the defrost vents under acceleration... but like i said, any help is welcome!!

notop46

There is no Mass Air Flow sensor. There is a Manifold Air Pressure sensor. The ECM uses the manifold pressure, RPM, and manifold temperature to calculate how much air is flowing into the engine.

Could be a vacuum leak that is opening when the engine torques to the side. Flex some of the vac lines while it is running to see if the RPMs jump up.

mtadd162

wouldnt go back to those part stores if i were you either lol. might try and sell you blinker fluid next...

mreigie1

shoot carb cleaner at every vacuum junction as well as along the vacuum hoses. Your looking for a surge in rpm's. Pretty common prolem when rubber cooks under the hood of your "easy bake oven" for years. Cheap place to start anyway. As far as the evap system another simple cause of that is a def gas cap. Ive found the simple things on a jeep seem to yield the best results.

bluejeep2001

The map sensor is mounted on your throttle body. Your evap leak could come from some of the rubber tubes at the bottom left side where they angle up from the main floor rail towards the engine, way down below the brake booster. Or you can check the rubber tubing at this box right above the rear axle on drivers side.

Saudade

This thread is 11 years old.

The OP hasn't been around since 2017!!!

cruiser54

POST DATE IS RIGHT ABOVE MEMBER'S USERNAME.

UKXJ

Hang on Cruiser, didn't you "like" that 11 year old thread, only yesterday?

cruiser54

Yep. Then realized the age and forgot to remove the Like. I fixed it.