[ZBlue89]

I need help.
89 Mustang LX, 302, Powerdyne 9lb, 70mm C&L MAF, stock TB, 19# injectors, MSD coil, wires, new plugs (copper not plat.), bbk shorties, bbk off road h/ no cats, flowmasters

Here's a time line...

2007- After WOT car boggs slightly and check engine light comes on. I give it a little gas or a rev and it's fine again. Once in a while it would stall. Never got a code on it. I suspected it could be bad O2 sensors but couldn't get the damn things out.

2008- Moving on, gave up on that and installed a 70mm C&L #19 MAF and a stock hypertech chip. Same issues but not quite as bad.

I know your wondering why I haven't fixed it yet...

2009 (RIGHT NOW)- Installed a Powerdyne 9lb kit with FMU and 255lph fuel pump. Boost feels great yippie! Until I let of the gas, this thing shakes and chuggs hard! Almost stalls everytime. I don't know if its lean or rich but its lacking something. It's starving. Especially does it after a WOT. I believe this issue to be the same thing I have had for years now.

I plan on getting a tune soon but is there anything I should look for in the mean time? Any help would be great. I want to be prepared to enter the dyno tune shop and not get ripped off.

Thanks in advance!

[pirotec354]

When you decelerate off of WOT can you smell a lot of gas or is there any popping coming from the tailpipe? This could be a MAF problem. Did you ever try cleaning the stock one before you replaced it? Just trying to get some more info so I can get a better idea of what this could be.

[pirotec354]

Also it seems odd that you couldnt get any codes off the eec if the check engine light did come on. Also thinking that it could be an egr related problem. Check out all your vacuum lines and your connections to your egr too. you may find something there.

[ZBlue89]

Someone else suggested I could have a vacuum leak but for a different reason. I am only seeing 5lbs of boost instead of 8 or 9. How do I go about checking for a leak? I have never done anything like that before.

[my89blubyu]

Try putting the screen off the stock maf on the c&l, i had a very similar problem until I put the screen on it. It has to do with the way the air goes throught the sensor.

[strtrcr50]

To start, I hope you took the hypertech chip off when you installed the powerdyne. Also, how do you have the C&L mounted? Is it on a powerpipe, or in stock location? Did you try clocking your meter? C&L's can be tough. Most people don't recommend them due to the unpredictability. What makes this hard is you had similar problems both before and after the C&L installation. Are you pulling both KOEO and KOER codes?

[ZBlue89]

I have the C&L with no powerpipe. I basically have it laying on its side. Should I try and rotate it? Also, I don't see how I can get the stock screen on the C&L without any interference.

Still only seeing 5#'s of boost. Could the belt be slipping that much?