Misfire And Surging

[matt333cars]

I Have A Surging Problem At Full Throttle With Boost Only At 14psi. The Fuel Pressure Is Stock Level With Stock Regulator. Will Blow Off Fuel Pressure Vaccum Hose And Brake Booster Hose Also When This Occurs. Sound Almost Like Spark Knock. Help!!!!

 

[turbojd]

What modifications are done to your car? what chip is in it, or is the car bone stock?

 

[matt333cars]

It Has A Crane 206 Cam, Stock Intercooler, Stock Throttle Body, Stock Downpipe, Cat Back Exhaust, 30lb Injectors, Mild Porting To Heads. The Engine Has Very Low Mileage. Ran Great For A While. It Also Has A Ported Stock Turbo.

 

[turbojd]

For one I would change out the stock fuel pump, if it's the stock one, then I would get an adjustable fuel pressure regulator for starters.Oh and a hotwire kit for the fuel pump. How long has the cam been in there?

 

[matt333cars]

I HAVE A HOTWIRE KIT TO A WALBRO PUMP, TRIED ADJUSTING PRESSURE WITH A ADJUSTIBLE ONE. THOUGHT IT WAS BAD. HAD ABOUT 65PSI AT FULL BOOST 14PSI. THE CAM HAS BEEN IN ABOUT 4000 MILES. CAN HOLD THROTTLE ABOUT 3/4 DOWN AND IT STILL RUNS GOOD, BUT WHEN APPLY FULL THROTTLE IT POPS AND BLOWS OFF VACCUM HOSES.I HAVE A CORRECTION ON THE CAM, IT IS A COMP 260H, SORRY!!

 

[turbows6]

For one, if the vacuum hose comes off the fuel pressure regulator you loose boost referenced fuel pressure and the engine could be going lean and knocking. 14#'s shouldn't be blowing vacuum lines off, you might want to replace them if they are worn out. Little zip ties don't hurt either.

 

[matt333cars]

Zip Tied The Hoses On, Still Getting Knock? Even Tried Race Gas (110) Did Not Have This Problem Before, Anyone??? Ordered New Chip From Turbo Tweak, May Also Try An Air Flow Meter....

 

[turbows6]

Do you have a good boost/fuel pressure gauge? If hoses are blowing off it's coming from excessive pressure in the intake at full throttle. Either from excessive boost pressure or from backfiring through the intake.