What is the vacuum reading on your boost gauge? Does it fluctuate?

Check your clamps to make sure they are nice and tight.

You can also pressurize the system by creating a boost leak tester. Go to home depot and grab a 2.5 white pipe end cap and drill a hole in it to insert a tire valve.

http://www.supramania.com/forums/sho...st-Leak-Tester

Comptech charges $100 for a rebuild of the fmu.

 

My vacuum reads 19hg steady doesn't move at all. During decel its about 22hg steady no fluctuation.

 

I have an CT FPR on mine and I do not get inconsistent AFR readings, obviously the hotter it gets the richer it will be but still i have only witnessed a .1 (very occasionally .2) difference generally from cold to hot weather, but i run a greddy emanage ultimate which will perform adjustments which keeps the AFR in check.

 

What fuel pump are you running?

 

That makes a big difference. The fpr set up with no management is purely mechanical, so I have seen as much as a full 1. difference from winter to summer afr. This is normal. .2-4afr daily fluctuation depending on temp/humidity is not uncommon either.

 

Why not just run the stock FPR and sell the comptech one for some cash if you havemthe emanage?

 

Well ima go out for a few runs and see what my AFR's are at today..

 

Did a few more runs..AFR's were still in high 12s low 13s. its about 85~90 degrees out atm. Turned another thread and FPRs dropped to high 11s low 12s. Will see what happens tomorrow. Seems liek afr responds well to the FMU change then gets leaner again..

I think I read a thread of Junky having similar issue?

 

Sounds like a weak fpr spring losing tension and fuel pressure decreases, but I would think this would happen over weeks or months, not overnight. You might be over stressing the diaphragm at this point with too much adjustment and fuel pressure is just becoming erratic. Fuel pump is still the other possibility.

 

I had the exact same problem. CT said it was related to my header,exhaust and test pipe. So I ditched the fmu and went with AEM.