retsell

Pressure and flow are 2 diff things. Could make pressure but not flow worth a ****. I think it is knocking partially because of the over boost. Its tuned for 6 - 7 lbs, not 8.5+

Flyer

iTrader: (1)

THe 8.5 should be fine on a stock RADIX tune. They tune it pretty conservative for such occasions I would imagine.

I say run it open header and get a scan tool hooked up to it while doing so.

WHen you are running oipen header, don't let it cruise much, kinda coast some, then get on it, let it coast some, then get on it again. The idea is to not let the lack of exhaust flow let fresh air back on those o2 sensors for very long. It will trick the computer and it will start dumping a **** load of fuel into the motor.

Hoover87

Okay, did some tests today and I think I found a problem.

Ran open headers this morning and woke up the neighbors, damn it sounded cool! Anyway, my boost is about the same with the headers open as it is with the full exhaust...about 7 psi all through first gear when I mash on her at stand still and in a hard second gear pull the boost kreeps up to about 8 to 8.5. Seems to boost a little moore after a few runs. Anyway, I deemed the exhaust okay.

Next test, went and got a 6 ft chunk of hose so I could monitor my fuel pressure guage from inside the cab during a run...here is where things start to look sketchy. Previously when I said my pressure looked good, I wasn't really able to monitor it while under constant load. Anyway, here is what happened:

Idle is about 45 psi, when I mash on it it goes right to 60 psi...as the RPM increases it fades to around 55-50...then she shifts to second gear and the psi jumps up again close to 60...then during that hard second gear pull the psi fades to about 30 psi at 4000-4500 RPM, right about where my pinging starts, right about where my boost is starting to peak around 8 lbs. Is it supposed to do that??

Any ideas on how to resolve this would be great!...if it is indeed a problem.

Thanks again!!!

O3GMC

if I was to guess I'd say something is wrong with the fuel pump or the tuning - it should stay at 60 at WOT

Flyer

iTrader: (1)

You are having fuel delivery issues ....

Did you install it yourself?

Try this ... turn the truck on (don't let it start), let the pumps run and build pressure. The pumps will shut off after 3 seconds. Watch the gauge and see if it starts falling. Tell me how fast it falls if it does at all.

retsell

Thinking FPR problem flyer?

Flyer

iTrader: (1)

yup ....
That little O-ring is a pain

BlownChevy

iTrader: (20)

I would check that..........and put that pulley on I sent ya!

Flyer

iTrader: (1)

Don't put a smaller pulley on until you get that fixed!!! If it's bigger, then by all means .. stick it on.

BlownChevy

iTrader: (20)

Bigger pulley.