Thread: MAF & fast idle

My can of cleaner has a little plastic tube that can be attached to the nozzel. Tube can be poked it through the wire mesh and directed where you want the cleaner to go.

Or do you mean the wire mesh won't let you get the tube in?

My TD5 MAF only had fine mesh at one end.

THe wire mesh was blown out of mine with an LPG backfire. Seriously!

The wire mesh is there to ensure that air flow into the MAF is uniform, if there is not about 30CM of straight tube in front.
In the 14CUX, you can remove the mesh by levering on a spring retainer.
In any case, where you want the cleaner is in the sampling tube of the MAF on older ones (hot wire type) or on the film surfaces of later type ones (hot film type).
There are two small wires in the sampling tube which you should be able to see when they are clean. The hot film type has a double sided "blade" sitting in a holder in the middle of the MAF tube.
Spraying the mesh in either case does nothing but make it look nice.
Regards Philip A

Originally Posted by 96 4.6

My P38 is idling at a very fast 1200-1400 RPM, and it is becoming very hard to drive, not to mention the cost for the fuel at the moment!!
I have removed the stepper motor and cleaned it, I have cleaned the carby body, and I have attempted to clean the MAF. It did this a few months ago and I did all of this as well as replace the stepper, but it was only after carefully blowing out the MAF with a compressor that it returned to normal. Is there a better way to clean it? I have a can of MAF cleaner, but it does not seem to get any into the sealed tube because of the wire mesh. It seems to disipate the spray before I can get it to go where I want it to... The wire mesh had some fine dust on it, so I am assuming that this is the problem, but besides a very expensive replacement, the actual MAF seems to be non serviceable... But I am sure that there are some genius's that have encountered similar problems and have a work around.. PLEASE!!!

Thanks in advance...

First, take out the wire ring holding the wire mesh into the MAF body, paint it (the mesh) green and throw it into some tall grass, I have no Idea why L/R put the screen there, it must create havoc with the airflow and if it is needed to filter particles out of the airstream then the air filter is a waste of space.
Every Fuel injected L/R I have ever owned, the first thing I did was remove this mesh, it has made no discernible change to the performance of the motor.
If you have dust on this bit of mesh, then your air filter is allowing it through, not good.
In the top left hand corner (just inside) of the opening of the MAF is a small hole with the Hotwire wires inside, you need to spray in this hole to clean the wires, do it with the engine running, or not.
I would also be checking for a vacuum leak at all of the many Vacuum hoses, a vacuum leak can cause the problems you describe, Regards Frank.

Originally Posted by p38arover

THe wire mesh was blown out of mine with an LPG backfire. Seriously!

Shows how much resistance to airflow if it can be blown out, Regards Frank.

So the consensus would seem to be that the mesh which is too fine to get the little tube from the can through is just there to keep the flys out... I do have a new air filter element, and just to make matters worse, it is a genuine one... The dust that was on the mesh was very fine, but that's gone now thanks to the can of cleaner (At least it has done something!).

So I'll check all of the vacuum hoses I can find for holes / cracks, and see if I can get the mesh out. One way or the other, I'll get access to the inner tube and get some cleaner in there.
Just as a thought, is there a replacement or addition to the tube for the can that I could use that would allow me to bend the end, and actually attack it from the rear? I could come in from the back if there was a 180deg bend and spray in there easily... That way I would not have to touch the mesh. I don't have a problem pulling it out, but LR must have put it there for some reason.

Thanks for the suggestions, I'll try them ASAP and let you all know if I've been successful successful...

Hopefully with the continued support of forums like this, we can all band together with our combined knowledge and keep these great cars going for a long time to come.

99% of the gunk that gets on the "Hotwires" is on the front of the hotwires, which is where they read the airflow, so you really need to clean the front through the little hole, there is a wire "circlip" that holds the mesh in, it is easily removed with a small screwdriver or O ring pick.
I would be checking, air filter, air filter box and any induction hoses to find where dust is getting in, there should be dust tracks to guide you, Regards Frank. P.S. please post up here any solutions to your problems for the benefit of others that may have same or similar problems, Thanks

AFAIK, the MAF cannot cause a fast idle.
It is upstream of the throttle body.
As suggested , look for vacuum leaks after the throttle blade, or a faulty stepper.

Just block off both ends of the hose to the stepper and see what the idle does. It should be a slow idle at about 550RPM. If it is fast then you have a vacuum leak somewhere. BTW, If the stepper mount is like that of a 14CUX, check the tightness of the bolts that hold it to the Plenum. If the idle is slow then the stepper is suspect even though you cleaned it.

Regards Philip A