PDA

View Full Version : Cleaning of Air Flow Meter/Vacuum leak



ytt105
23rd March 2006, 09:36 AM
I have a 1993 RRC, 3.9 V8. Runs very rich, you can smell it, fouls up the plugs real easy.
I've take the Mass Air flow Meter apart and sprayed carby cleaner through it. It looks clean but the two wires aren't the thin wires I was expecting. One is what looks like a resistor, complete with different colour bands, the other looks like a white/cream resistor without bands.
Is this what I should be seeing?

Also, I think I can hear a vacuum leak when I'm near the air flow meter but can't find anything. How many vacuum connections are there on that side. I've tried the old vacuum test of opening the dip stick to introduce a vacuum leak and get no change in idle (which if it was the SAAB would mean there IS a leak). Does this mean there is a vacuum leak or not.

DEFENDERZOOK
23rd March 2006, 10:22 AM
<span style="color:blue">you could simply be hearing the air getting sucked through the plumbing...
inlet manifold....and not an air leak.......


check your coolant sensor is working correctly as this can cause it to think it is cold
and richen the mixture to compensate....</span>

PhilipA
23rd March 2006, 11:01 AM
There is no vacuum at the MAF sensor.
Vacuum is only caused by the throttle blade which is after the MAF.
There can be a bit of vacuum at full throttle caused by air cleaner restriction , but at idle there is none, zilch.
You can generally clean the MAF without dismantkling. just spray into the little hole. I always thought they were shiny wires, but you cannot see much through the hole.
Regards Philip A

4bee
23rd March 2006, 04:17 PM
I seem to recall getting this "suction" noise at the air cleaner box on the Discovery, & pinned it down to it sucking through the box drain holes.

PhilipA
24th March 2006, 11:34 AM
Just a thought.
Do you have the O ring between the MAF and aircleaner in position correctly? Maybe the air noise you hear is from there.
This will not affect running in the short term, only let unfiltered air in.
By the way , you should clean the sensor wires with no residue electronic cleaner.
regards Philip A