boosting problems

[skyline-r33-gtst]

hey guys
ive owned my skyline for about a year now. when I first got her she had no Boost Solenoid and was running in safe mode. now ive put a Boost Solenoid on a few months back and she keeps losing power in second gear onwards. its like when I hit boost she lurches forward dead quick like someone slammed on the break for half a second then shoots off into full boost again. if I put my foot down really slow then it does not happen. its like a fuel or spark cut. ive tried solving the issue buy buying new intercooler pipe work and hoses and had her smoke and pressure tested that never showed any issue. also had sure fire coil pack harness new plugs new coil packs, new air intake hard pipe. and tried 2 separate maf sensors on it aswell trying different dump valves. now its at the point its driving me nuts not being able to find the issue. its got a full 3" decat and exhaust standard turbo a fmic . I'm wondering if ive done something wrong when fitting the boost solenoid.. i have one vac pipe running from the actuator to the top solenoid connector and the bottom one goes to my lower intercooler heat pipe. I'm told that it should have a t piece on it connected to another pipe. but I don't have one. is it suppose to be connected to somewhere on the Intake Plenum ?
any help would be great as I just want the car to run good for once
cheers

[Kwakerswull]

Is the std solenoid 2 port? When you state it was running without one before i presume you mean it was running actuator pressure?

So the vacuum line ran from the compressor side of the turbo to the WG?

I’d suggest getting a map done now that you’ve fitted a solenoid, or uprate it to a 3 port and plumb it like so.......

Port 1 ( left side) going to WG
Port 3 (middle) going to Turbo
Port 2 (right side) VTA, some have this return to the intake but it’s not needed.

For a 2 port you’d have

One port going to turbo and Wg with a t-piece but the line from turbo to t piece would have a restrictor pill fitted and the other line would go to the intake after the maf sensor.

I’m sure that’s correct, I’ll double check.

[skyline-r33-gtst]

hi yes it was running with out a boost solenoid. the vac pipe was going from the actuator into the intercooler pipe. its a standard solenoid and only has 2 wires. and also its a standard ecu. I do plan on getting a nistune board or a link g4 ecu fitted and mapped but wasn't sure if this would cure the problem.

[skyline-r33-gtst]

[Kwakerswull]

So your one is being fed from the intercooler pile? So that line goes straight to the solenoid or do you have a t-piece fitted?

My thinking is from the intercooler pipe (compressor side) it should go to a t-piece which then goes to solenoid and the other goes to the WG. The line that goes to the solenoid from the intercooler pipe should have a restrictor pill I’m sure.

Then the other port on the solenoid goes to the inlet pipe post maf sensor.

I’m not sure which port is which though, I’m more clued up on 3 ports.

[skyline-r33-gtst]

Kwakerswull said:

So your one is being fed from the intercooler pile? So that line goes straight to the solenoid or do you have a t-piece fitted?

My thinking is from the intercooler pipe (compressor side) it should go to a t-piece which then goes to solenoid and the other goes to the WG. The line that goes to the solenoid from the intercooler pipe should have a restrictor pill I’m sure.

Then the other port on the solenoid goes to the inlet pipe post maf sensor.

I’m not sure which port is which though, I’m more clued up on 3 ports.

I have no t-piece fitted. I'm not clued up on engines. but I will follow your instructions when I start on it again tomorrow and let you know how I get on. but as far as I can tell there is only one pipe from the intercooler itself which is from the actuator. ive tried looking on various sites but haven't had any joy with it.

[ChrisPackit]

Thats a stock 2 port Nissan OE solenoid, and I bet that it's not running with the brass ferrel in the pipework which restricts the boost to 0.5 bar. What youre experiencing is a safety limit called fuel cut.

Fit the brass ferrel back inline and it will sort it out.

HTH

[Kwakerswull]

Restrictor pill it's called,as mentioned above.

[skyline-r33-gtst]

hey guys I found out the reason for the boost issue, it turns out that the idiot owner before me cut the earth wire for the boost solenoid at the ecu, , I had it in the garage for about 5 hours b4 the noticed it as they was checking for usual problems. luckily it was a friends garage, so I was only charged £60 ... happy I have the car boosting now.... ooossshhhh