Problem with after market boost controller

[immortal]

Hi All,

I had a good search through the forums but wasnt able to find anything that would help much, hoping you experts might be able to shed some light on whats going on.

Yesterday I bought a GFB adjustable boost valve. I have a 93 R33 GTST which has a factory electronic boost controller, that seems to boost the turbo from about 5psi to about 7psi once the engine hits about 4500rpm ...

To install the after market valve/controller, i disconnected the factory electronic controller (solenoid), blocked off the hose that vented pressure back into the air inlet, and connected the after market controller between the two hoses that USED to go into the factry electronic controller (i assume the bleed valve around the wastegate?)...... Firstly ... im hoping this is correct. (i can get some pictures posted up if your note sure what I mean).

Anyway, I wound the valve right down to the lowest setting (supposedly factory boost for the turbo) and gave the car a run .... no problems driving the car normally, however when I start to nail it a bit in second and sometimes third .. when the car reaches about 4000-5000rpm, the boost suddenly skyroockets on the guage, however i loose boost to the engine, and thre car starts to jolt like boost is coming on, off, on, off, on .. etc etc ... almost like its reached peak boost? or not enough air in? no idea!!

Can anyone help with this? I dont have much experience with moddng engines, though I did have a friend helping who knew a fair bit about it, but its got him stumpped too. I tried it both with the factory controller connected to power, and disconnected from power (thinking it may have been an ECU thing?) .. still no good.

Any help would be greatly apreciated.

Thanks

[cameron]

Picture's will help,

Have you got a boost guage this might help, seeing what it hits when you said "skyrockets"...

Sounds like its hitting fuel cut - 14psi around abouts. Or its have a miss-fire becuase you are running more boost the spark on the spark plugs can't jump the gap and its arking out to other places and not giving a strong enough spark

Re-gap the plugs to 0.7 if this already has not been done.

Jun

[RT33]

the bleed valve should go inbetween the wastegate and the inlet pipe (going towards the throttle body) and the bottom vaccum hose on the standard boost controler should be blocked off with a bolt or srew (whatever u can find).

The spark plugs should be gapped to 0.8mm

P.S dont kill your turbo!!!!

[immortal]

Hi,

Thanks for your assistance guys ... any more hits/tips would be apreciated. I might try a few things, including putting an after-marker guage on to see exact boost.

Can someone tell me ... what boost/psi can a stock r33 run (generally) before its getting a bit too high ? 10psi? 12psi? 14psi ?

All its got is pod filter, BOV and GFB adjustable boost.

I dont wana go too high and blow it.

[bangahh]

I have the same problem as you...............

at the moment im saving up to fix it. Either regap to .7 or .8 mm OR fix it with splitfire coilpacks. $650 ish....

my cousin has the same setup but he's car doesnt do it, just mine :-( you also might want to upgrade the fuel pump.

[immortal]

Hi bangahh ...

Pain in the ass isnt it ... although ive it to it a stage now where it doesnt really shudder as in boost on, off, on etc at high rpm .. it just doesnt give any more boost at anything past say 4-5k rpm ....

[ramjet]

yeh i had same problem.. when i took it to a performance shop they said my boost controller was incorectly fitted, and now that its off it runs fine.. im getting it refitted this week (properly i hope) on the dyno, so il c if it was the incorrect fitting that was doing it.