narrowing down overboost issue

[SevenT6Vet]

Hooked boost gauge to wastegate side of solenoid valve (solenoid valve is brand new)...boost gauge reads zero and vehicle continues to overboost. factory boost gauge still spiking (i'm not flooring it btw, and i never let it peg or get into fuel cut or take it over ~3500 RPMs).

I bypassed solenoid and hooked boost gauge b/w turbo and wastegate, steady 6psi on real gauge and factory gauge confirms by only reading 1/2 boost. I can floor it and it runs through gears like normal. Truck drives completely normal, just low on power.

So, here is where I am:

1) bad wiring to boost solenoid?
2) aftermarket chip installed? (I haven't checked yet, came inside to grab something to eat real quick and this is what i'm inspecting next)
3) ????

I pressured wastegate with 5psi and it opens fine.
Most everything is new: vacuum lines, cap, wires, plugs, ignition coil. MAP sensor is original, but "appears" to work as it reads vacuum correctly and factory boost gauge more or less (in it's best effort) coincides with the boost gauge I installed.

Only mods to vehicle are drop in K&N filter and catback exhaust. no check engine lights are on (and light does work).

I talked to AKM today and i'm ordering a cable this week.

As usual, thanks for any and all advice

 

[WyoSyclone]

Re: narrowing down overboost issue

Did you adjust the wastegate rod??

 

[SevenT6Vet]

Re: narrowing down overboost issue

Did you adjust the wastegate rod??

*edit* I have not personally adjusted it

I don't think it needs adjusting. Correct me if i'm wrong, but here is my logic: when I hooked up the mechanical boost gauge to the downstream side of the boost solenoid, and it was reading zero as I accelerated and the factory boost gauge began to peg, that leads me to believe that the ECU isn't properly communicating with the solenoid valve.

When the solenoid is bypassed, At WOT the mechanical boost gauge reads 6psi and the stock boost gauge reads ~50%. Seems to me rod is working fine. It's just not getting any pressure when it should be.

Shouldn't the solenoid valve be bleeding some pressure to the wastegate as boost come up?

 

[SevenT6Vet]

Re: narrowing down overboost issue

ugh, just pulled ECU and found an hypertech chip. trying to figure out how to post picture so i can get additional help. i'd really like to return this thing to stock ECU chip and then tune.