I had a mechanic put in a Professional Products 70mm throttle body and 70mm egr spacer and 76mm C&L MAF which is supposed to be calibrated to 24lb injectors. It runs like crap. Surging, stalling, less power than with stock gear.

In reading the docs, it seems there is supposed to be a "blue tube" to calibrate it to 24lb injectors. You can buy a different tube to calibrate the same housing to other sized injectors.

Since I didn't open the boxes, and I didn't install it, I've never seen what that "blue tube" is supposed to look like or where it is supposed to go. I am guessing that tube is supposed to go into the small tube cast into the inside of the MAF housing into which the actual sensor wires are projected. I just took mine apart and looked at it and that tube is totally empty.

Can anyone verify what this "blue tube" is and where it is supposed to go? I have a feeling that it is missing on my car and that's why it is running so badly.

 

If you can look in the meter and not see the air tube then he did not put it in. the tube is not blue it is aluminum with a spot of blue on it that's all. But you are saying that there is a tube in there so it sounds like it is in there that tube you are talking is screwed to the meter the screws are under the sensor it is the whole tube that you change to change injectors calibration. I dont like the C&Ls just for the reason you are having they are problem prone. maybe he could of put the tube in the wrong direction they may give you some problems also. take the sensor off and and look at it to make sure it is right.

 

The sample tube should have a blue marking on it, but sometimes the new housings aren't marked when new.
The aft side of the sample tube (or TB side) should have the color marking on it.
You can also take a pair of calipers and measure the inlet and outlet of the sample tube.
Compare your sizes to the table on my site...
http://www.freewebs.com/vristang/clsampletubes.htm



Some other questions that you MUST answer...
What ecu are you using? We need to know the catch code... A9L, A9P, A3M, X3Z???
What are the first 4 digits on the sensor in your MAF meter? F2VF, F1SF, F1ZF???

This info is just as critical as providing the injector size.