This is a good one to figure out, hope someone can give me some ideas!

[86BGN]

My set up is a TA-49 turbo, 43.5 lb 009 injectors, stock intercooler, DIY alcohol kit, Turbo Tweak alcohol chip, adjustable regulator, hot wired Red’s XP pump with a TH down pipe….

Before I could run 25 PSI boost with minimal knock (.7-1.0) O2’s in the 780-820 range. The car ran awesome

Now I can not achieve more than 22 PSI consistently (it might spike in first to 25 PSI) and knocks like there is no limit on the scan master (I saw 27.0 degrees) when the timing curve comes on in the chip… Second and third gear the O2 starts taking a nose dive to low 700’s but seems sporadic along with the knock. Also I have been having some sporadic surging idle problems.

The alky pump is fine, that is the first thing I thought to check because of the O2 MV and all the knock but that still doesn’t explain the other problems?

Thanks

 

[Joe Tiano]

It could be several things..have you verified fuel pres @WOT..how old is the fuel filter?.. maybe the fuel sock in the tank has collapsed.. or the piece rubber hose that connects the pump to the hanger has split or is leaking..is your FPR working properly?..put a pressure guage where you can see it and go from there!

 

[86BGN]

I have put a pressure gauge on it at idle and it holds pressure fine. My gauge isn’t long enough to do a test drive with it though. The thing that puzzles me is I am not able to make the same amount of boost as before? Would a intake leak cause the low boost and also the fuel pressure regulator to not work correctly?

Thanks for the reply

 

[Joe Tiano]

well..you may have just blown a vac hose off somwhere..check around the egr valve and the hoses near it..do you have a boost guage that shows vac?..has it dropped?..usally it an exhaust leak that causes loss of boost..cracked header or split x over pipe..good luck and get enough hose on that guage to be sure you have the fuel psi...joe