T Piece Boost Controller

[shaun123]

hey guys,

i recently bought a turbo tech manual boost controller off ebay, and loosened the screw all the way (0.7bar), however when i have the boost controller installed, my car develops a big misfire...

Is there any obvious cause for this?

mods: bosch 040, turboback exhaust, pod

[99 GTT]

I would say 10 PSI and no tune = BAD

Restrictive exhaust would not help and the manual boost controllers are known to spike so could be way more boost and leaning out. (Not a big fan, better to use electric one)

You realy need a tune before you do damage.

[PM-R33]

You pretty much answered the question yourself "missfire". A missfire is a poor spark, so either your spark plugs need replacing or your 15 year old coilpacks aren't up to the job anymore, or both.

Edited June 14, 2010 by PM-R33

[JonnoHR31]

I would say 10 PSI and no tune = BAD

Restrictive exhaust would not help and the manual boost controllers are known to spike so could be way more boost and leaning out. (Not a big fan, better to use electric one)

You realy need a tune before you do damage.

it wont be running lean. more boost sends things rather rich with the stock ecu and turbo.

as PM-33 said, poor spark. i'm assuming its under full load around 4500-600rpm? if so the most likely culprit are tired coilpacks. can try taping/siliconing them or get new ones. in the meantime you can gap your plugs down a bit.

have a search around here, theres countless threads on this

[mad082]

+1 for poor spark. higher boost levels put more stress on the coils and spark plugs.

[shaun123]

hey guys thanks for the replies,

i have recently just replaced my spark plugs gapped to 108mm, i sussed out the coil packs and there are no visible hairline cracks etc.. in them.

With the stock boost solenoid, with the exhaust my car runs 7psi <4500rpm, then above 4500rpm it goes to 10psi... and starts to 'misfire' when its on 10psi.

also cleaned the A/F meter, replaced the fuel filter, air filter and reset the ECU.

Edited June 17, 2010 by shaun123

[PM-R33]

Run 0.8 gap plugs and it will fix your problem. If not than obviously the coil packs are no longer good.

[mad082]

hey guys thanks for the replies,

i have recently just replaced my spark plugs gapped to 108mm, i sussed out the coil packs and there are no visible hairline cracks etc.. in them.

With the stock boost solenoid, with the exhaust my car runs 7psi <4500rpm, then above 4500rpm it goes to 10psi... and starts to 'misfire' when its on 10psi.

also cleaned the A/F meter, replaced the fuel filter, air filter and reset the ECU.

the coils may look ok, but may not be ok. try taping them up with electrical tape and see if that helps at all, but my guess is that you'll be up for new coils.

[GTRPSI]

Leave your coil covers off and run the engine at night in the dark.

Enjoy the electrical storm.

Id be testing plugs regapped to 0.8mm first though, before you put the coil covers on have a look for sparks arcing around the coil packs.

I also run a smear of dielectric grease on the ends of my coil packs to help stop spark loss on both my GTR and XR6.

[Legumis]

had the same issue.

Fixed by gapping the plugs to 0.8. Also smeared a thin layer of high-temp silicone gasket-making crap around the square block part of each coilpack (theres a thread somewhere in the DIY section), since I had them out anyway.

[jordanlisa69]

gap plugs then put it in 5th gear at 50kph then floor it. if it missfires then it will missfire badly under this load and its gona be your coilpack. just spend about $250 bucks on a set of heavy duty dsr coils. they are some of the best

[J_R33]

i had the same problem (miss-firing bout 4500rpm) - set of splitfire coil packs and splitfire plugs gapped to .8 fixed it right up :D

[Galois]

heavy duty dsr coils? what are these? (other than a crapload cheaper than splitfires and yellow jackets)

[Marcus89]

gap plugs then put it in 5th gear at 50kph then floor it. if it missfires then it will missfire badly under this load and its gona be your coilpack. just spend about $250 bucks on a set of heavy duty dsr coils. they are some of the best

This sounds like an excessively bad way to diagnose the issues sure it might work but the strain on the motor/gearbox would be stupid. 50kph in 5th and full throttle lol

[jordanlisa69]

This sounds like an excessively bad way to diagnose the issues sure it might work but the strain on the motor/gearbox would be stupid. 50kph in 5th and full throttle lol

Its actully what the mechanics do to try help diagnose the problem. Probly the least stressfull on the engine as well. How would it be more of a strain at 1500 rpm then at 4500 rpm? Takes you about a second to find out how badly its missfiring. And then you can fix it. Unless you want to continously thrash your car finding out how badly its missfiring. And pretty sure it wouldnt have a problem with the gearbox. How would it?

[jordanlisa69]

heavy duty dsr coils? what are these? (other than a crapload cheaper than splitfires and yellow jackets)

I got them off trademe coz im in NZ and my mate has them in his 25det gts4. My engine runs absolutely perfect and i wouldnt have anything else to be honest. Nothing is going to out perform them for how much power i have. PLus they are like 400 bucks cheaper then yellow jacket and stuff lol

[ClutchBurndout-:(]

i thought you could run 10psi on stock ecu with no tune, it just runs rich? could be wrong though

[mad082]

no, you are correct. stock turbo @ 10psi on stock ecu is fine 99% of the time. there will be the odd car that will hit rich and retard at this level, but very few, and this can come down to innacuracy of the boost gauge (may be reading 10psi but the car is actually boosting 11 or 12psi)