one my friends has a 2001 comptech supercharged s2k. has comptech header, gutted cat (soon to be replaced with resonator), apex'i N1 single side exhaust, apex 'i NEO...and the rest is stock.

took it to the dyno (RLZ) yesterday and tried to make a pull, and as soon as it his 2psi it shot to 17:1... Our first inclination was a dead FMU...so howard pulled it off and i disassembled it to check the diaphragms...and all were perfect. So it went back on and another pull with the same results.

we couldn't try another FMU because comptech uses a built in FPR which replaces the stock one...and we did not have one on hand, and the only y8 one was a customers so we couldn't use it.

Now my thoughts are.....is the fuel pump dying? Since it didn't run out of fuel until it was into boost....can the fuel pump just not put out at the higher pressure due to the FMU? Car runs amazingly well out of boost and part throttle...but it REALLY sucks not being able to go WOT.

 

Is the fuel pressure rising at the correct ratio?

 

no fuel pressure gauge

 

They didn't have one at RLZ? In that situation I can't think of any other reasonable way to diagnose the problem aside from swapping parts.

 

i'm sure howard had one....but chad, howard, and myself worked on it for 5 hours. comptech's a bunch of idiots for the way they designed the kit, so we had to fix that stuff...then made a few pulls...the swapped some stuff...made pulls, then just gave up. My friend is thinking about just getting an EMS anyways....but that's not gonna help anything if the fuel pump's dead.

 

If it was my car I would get rid of the FMU.
I would buy some aftermarket injectors & a real engine management (aem ems) etc.

Get a wideband installed asap too :-)

 

wideband is installed............he's buying an ems now as well

 

Good stuff!

 

hope so....i guess we'll find out quick if it's the fuel pump or not lol

 

You need a fuel pressure guage to know for sure if your pump cant keep up...

 

yeah.....if you'd read, you'd know that was already covered, and is now a moot point anyways.....

 

I understand that...
I did see that you didnt have a fuel pressure guage...
I wasnt ASKING if you had one. I was simply informing you a fuel pressure guage WILL tell you if your fuel pump is keeping up or not...

But if your friend wants to buy an EMS and a wideband to check your fuel pressure, go for it!