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Senior Charter Member
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613 Posts
Discussion Starter · #1 ·
I've been having a heck of a time getting my cold air setup to behave properly. Let's go over a quick run down of its lifespan.

Hooked it up with the filter and air box positioned in front of the belt, mounted to the x frame brace. It pulls air in from the radiator area. A 4" tube feeds air up the MAF.

This setup worked fine when I had a 75mm MAF, and 24lb injectors. Idle was steady.

I switched to 30 lb injectors and it took me 3 MAFs to finally find one that did not have a surging idle (its a PMAS Velocity 95mm).

When I hooked up the coldair setup it went back to a surging idle. It seems as though the motor isn't getting enough air. I was thinking that maybe I have too many turns in the 4" tube, but why would it have worked fine with the previous MAF?

I'm thinking of scrapping the cold air setup. Right now the filter is sitting next to the passenger side vent and it seems a little less hot in that position. Only problem is kenne bell really stresses a cold air system. I'm thinking a methanol injection at this point would have been easier and less time consuming to setup. Many I should bite the bullet and go that root.
 

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Premium Member
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1,684 Posts
I'm with barry on this one. Did the EEC get reprogrammed to know it is dealing with 30lb injectors and a 95mm meter? Both will change the air/fuel ratio for a given electrical signal.

I put a kenne bell in my 2000 mustang and remember them saying not to use under hood air because of the preheat from the radiator. Is there a way to breath from the area above the passenger front wheel? I've seen recent posts on the 4.6 forum with a nice setup in that location. Easy to get to the filter too. Just a thought.

John
 

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Senior Charter Member
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613 Posts
Discussion Starter · #4 ·
I didn't burn a chip, but the MAF from PMAS is calibrated to my computer X3Z (1993 cobra) and 30lb injectors.

I'll check the 4.6 forum because that's where my filter is now.
 

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8,276 Posts
Try rotating the MAF in the tube, just loosen the clamps and move it 45 degrees at a time and see if it helps. Often you can get the metering wires in a slightly different area of the air stream and it's enough to fix an issue like you have.
 

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Sounds like you have a similar setuop as mine...I've got my cold air box right on top of the x member with a 80 mm pro-m calb for 30s right in the box..... I've got a 5" hose coming from the oil cooler opening into the box... no surging issues with mine..You shouldn't have to reprogram the computer because the computer will copensate as long as you have the mass air meter calb for the size injectors you are using.... but definately do ge a chip burnt after everything is set up and running good just to be safe..... ...If you'd like I could snap a few pics tonight and send them to you tonight...
 

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Senior Charter Member
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613 Posts
Discussion Starter · #7 ·
After replumbing everything again so the tube running from the air box to the MAF has less kinks the car runs better, but still is a little bit rough.

I don't know if I would call it surging, but I have it set to about 900rpm and if its left to idle for a while it will occasionally drop down to about 750-800 for about 30 seconds and then rev back up to 900-950. It just doesn't seem as steady as the car was previously, but maybe that's just the way it is with the bigger injectors/supercharger.
 
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