M35 Boost Issue

[joshm35]

Guys,

Have noticed when I do long trips in stagea every now and then my boost will.go from 9/10 pound to getting restricted to 5pound till I reset ecu via turning off car. No dash warning lights and yes they work. Any ideas guys??

Edited August 7, 2012 by joshm35

[scotty nm35]

Which gauge are you using? The minimum boost on the stock actuator is 7psi...

[andy65b]

I had a problem with the Boost Solonoid where instead of getting 13psi max boost I would get only 7psi.

My problem had no CEL light and was solved each time by turning the car off and restarting. The cause always seemed to be giving it a few revs up a particular hill.

I changed my Boost solonoid and the problem was solved. The Boost solonoid sits on the passenger side of the car under the plastic engine cover. It is bolted to the side of the plenum and has 2 small rubber hoses running out one side, 1 to the intake and 1 to the turbo actuator and one hose rinning to the front of the car that connects via a T piece to the boost sensor on the intake.

I believe you can clean a solenoid but I did not try that.

Cheers

Andy

[scotty nm35]

If the solenoid is blocked it will lower the boost, if there is a leak it may go higher causing the ecu to pull it back.

The hose from the solenoid that T's into the boost line has a restrictor in it. If it has been replaced that could make the boost rise too high causing the same issue. Have you changed the exhaust to 3 inch? that would cause it to run higher too.

A way around it is to trick the stock map sensor into thinking the pressure is fine, you could use a small pressure regulator if you wanted, set to 12psi, but I would be getting a better boost gauge first.

[Sage222]

i removed the factory one and replaced it with a turbosmart easy 5 mins fix. Boost comes on much better and smoother now.

[Sunkist]

i removed the factory one and replaced it with a turbosmart easy 5 mins fix. Boost comes on much better and smoother now.

QFT.

Buy boost gauge

replace with a turbosmart(or the sort) set it to 14psi or whatever the boost setting is and bypass the lines for the standard solenoid. Leave the standard one plugged in to avoid CEL. problem solved.

Edited August 8, 2012 by Sunkist

[joshm35]

I had a problem with the Boost Solonoid where instead of getting 13psi max boost I would get only 7psi.

My problem had no CEL light and was solved each time by turning the car off and restarting. The cause always seemed to be giving it a few revs up a particular hill.

I changed my Boost solonoid and the problem was solved. The Boost solonoid sits on the passenger side of the car under the plastic engine cover. It is bolted to the side of the plenum and has 2 small rubber hoses running out one side, 1 to the intake and 1 to the turbo actuator and one hose rinning to the front of the car that connects via a T piece to the boost sensor on the intake.

I believe you can clean a solenoid but I did not try that.

Cheers

Andy

This sounds exactly whats going on. Do you know the price and numbers of a new solinoid?

[joshm35]

If the solenoid is blocked it will lower the boost, if there is a leak it may go higher causing the ecu to pull it back.

The hose from the solenoid that T's into the boost line has a restrictor in it. If it has been replaced that could make the boost rise too high causing the same issue. Have you changed the exhaust to 3 inch? that would cause it to run higher too.

A way around it is to trick the stock map sensor into thinking the pressure is fine, you could use a small pressure regulator if you wanted, set to 12psi, but I would be getting a better boost gauge first.

Standard hoses and exhaust

[scotty nm35]

No idea on the part number but I have a spare one here if you need it...

I would just bypass the solenoid and try that for now, as numb nuts suggested.

[Sunkist]

for now? its what I would be doing permanently.. keeping or replacing the solenoid is not going to fix the factory safety drop in boost. it is spiking with the cold weather and/or not allowing the car to warm up before boosting. mine used to do it all the time and it pissed me off. the only way to get around it is by bypassing the solenoid with a manual/electronic boost controller.

once again: problem solved.

plus i cant imagine the worth it:price ratio for a new solenoid, which is most likely not going to fix the issue.

[joshm35]

Cheers guys. Much appreciated.

[andy65b]

This sounds exactly whats going on. Do you know the price and numbers of a new solinoid?

No, don't know the cost. BUT either take up Scotts offer or get an aftermarker boost controller. Even with the wastgate actuator spring Mod the car felt stronger on initial boost when I used the Greddy Profec B boost controller. It bypasses the factory one so no more problem.

Cheers

Andy

[Sunkist]

Cheers

Andy

[Sage222]

no CEL with factory controller removed mate. Been running like this for about 6 months.

[Sunkist]

no CEL with factory controller removed mate. Been running like this for about 6 months.

Well there you go! I cbf taking it out and leaving up to chance on whether I'd have to limp home

[Sage222]

yeah i thought of keeping it though it's one less thing i gotta worry about second guessing me bleed valve

[Sunkist]

yeah i thought of keeping it though it's one less thing i gotta worry about second guessing me bleed valve

Just keep it in the glove box or boot hiding spaces, if the problem ever occurs plug it in and drive home?

[Sage222]

good call its the shelf right now.. will move it

[joshm35]

I cant seem to find the write up bout the aftermarket solinoid install. does someone have the link bookmarked?

[joshm35]

Think I found it

http://www.skylinesaustralia.com/forums/topic/370714-m35-boost-bleed-valve/page__hl__m35%20boost%20controller