Intake sensor...

[cyrus]

Okay my bundle of joy and sometimes pain is being stupid again..


starts up fine... idles great til i hit the clutch in and let off of it. once i push the clutch in and let it out it drops down to 350~400 rpms and acts like it's going to die. played with the sensor to the left of the intake tube where the filter goes and it's nto that... the o2 sensor thing that goes inside the filter is in there but i don't know... it seems like this might be the problem to me... am i wrong? adjusting the idle does nothing to this... if i hit the gas it runs fine but as soon as i let it idle it acts like it'll die again.


running out of patience with it.. =\

[monkeyracing]

I'd be having a look at the idle air control valve. If it gets gummed up it will screw up your idle. Follow the big rubber hose back from the plastic part of your intake, back to where it connects to the thing hanging off the side if the intake manifold. That's the IAC valve.

Jim

[cyrus]

will check asap. thanks.

[cyrus]

update!! played with it last night... dropped it to 500 again.. still odd... i went to the MAF.... pulled the plug BAM ran better right then. plugged it back in there. 500 again. so this means MAF is bad correct? also. how much are these? difficult to fix?

[jglutz]

What year car?

Something does not make sense....removing any of the critical sensors should have forced the check engine light to come on! Or at least stored a code that can be obtained.

[FB71]

I'm guessing its an Aspire? The Festys have a VAF, and if you unplugg them, the engine stops. By unplugging the MAF, you send the PCM into FMEM (Failure Mode Effects Management). Basically, the PCM recognizes that the MAF signal is missing, so it plugs in a known-good value based on other parameters (throttle angle, coolant temp, etc). So yes, I would say you have a MAF problem. Before you replace it, examine it closely. I've had several occurances like this with customer vehicles (Ford dealer tech previously), and most often, it was a small piece of debris in the sample tube (downy bird feathers were the most common). Any disturbance of the airflow in the sample tube will wreak havok with the sensor values.

[kzbill]

always helps to know what kind of car doesn't it

[cyrus]

yea sorry posted it in the other thread. thought i did this one too. 94 aspire.