HELP! weird bog/boost problem! help asap at track now! naked chicks inside!

[Joe]

Ok I lied about the naked chicks but I've got a serious problem.

I'm out of town at phoenix international raceway at a 3 day event. There is money on the line so I HAVE to have a car by sunday!

Car felt great till the end of the 2nd session. Comming out of the last corner car felt like it had no power. No problem. Boost leak.

Pull in, tighten all the clamps, take it for a spin, feels the same

Problem: under wide open throttle it hits full boost but feels like its surging with power. Boost is constant and spools normally. There is NO misfiring. Its perfectly smooth to redline just surging with power.

What I've checked:Boost leak tested. Pressurized the intake track from the turbo to the throttle body. Holds 30psi with NO leaks.

Pulled spark plugs, all look normal. Slightly on the lean side but 30 miles of wide open throttle will do that on a stock setup..nothing out of the orinary.

Cleaned massairflow sensor. Appeared normal

Checked the turbo, no shaft play. Feels PERFECT. I'm actually surprised how solid it felt lol.

Suggestions?

Please! I'm hurtin y0! This weekend is costing me an assload of money haha

[Carl H]

check ect sensor and swap if have access to one, else check base timing and hard reset the ecu thru diagnostics as well as disconnecting the battery.check for damaged wiring...the heat might have finaly taken its toll

[Joe]

Ooo ect! Didn't think about that.

And idea what voltages I should be looking for? I know if its open its gonna read strange...

Resetting timing is on the list for am tommrow. I'm nearly positive the timing is ok I've felt it way retarded and advanced, never had this problem

Thanks for the suggestions carl

[Yellow4g63]

CAS going bad? borrow a friends and swap it in. RB20-25 same thing, my friends 25's cas took a dump and the car would spool just not make any power at all. I gave him a spare CAS and that solved the problem.

[Joe]

I had my cas go out about a year ago, this feels NOTHING like that...I don't think I'm gonna be able to source one before sunday....

[USMCgetsome]

cas and check the tps. reset tps. something to check.

[Evo_bill]

I don't see naked chick inside...

[rbosacco]

does your car have a cat on it kamin? a buddy of mine melted the cat on his turbo civic and complained of similar problems. or maybe it could be some other kind of exhaust restriction. does the car physically sound any different?

[Joe]

Well I "overslept" but I'm on my way to the track now.

Car has no cat and sounds the exact same as it always has. No change.

And I'll check the tps first thing.

Thanks guys

[Joe]

Ok checked tps. This is where it gets strange

Engine was origionally an automatic.

I have 2 plugs. Grey and brown. Grey is the top one, brown is the bottom.

Grey plug has no power or ground.

Brown plug has power, ground, and appropriate signal voltages. (5v, .3 -4v at wot, and ground.)

I was always under the assumption the grey one was for the ecu brown for the auto trans.

Plugs are different sizes by about 3mm (thanks nissan. ***holes) so I'm gonna splice them together and see what happens....

Ect checked out normal. Has good resistance across it and supply voltage.

[Kansei240sx]

This is a dumb question, but what is the ECT sensor?I think i know what it is, i may call it something esle.

[Joe]

Engine coolant temp sensor.

[Joe]

Tested maf and fuel pump

Maf reads normal and fp is getting full voltage.

I'm honestly stumped lol

[Kansei240sx]

Engine coolant temp sensor.

oh oh, i always called it the CHTS ( Cylinder Head Temp sensor )

[Dramier]

Are you sure it's engine related?

Perhaps clutch or a stuck caliper? Smell anything after a run?

Perhaps the filter is clogged and collapsing... do you have any kind of datalogging capability?

[RB20DETodd]

what about the piston rings you just fried!

[Joe]

Air filter is fine, and there is no way its clutch related. When a clutch goes rpm usually goes up, speed stays the same. This is nothing like that.

[300Plus]

Kamin, man this sounds EXACTLY like the problem I've been talking to you about for the past few days. Mine happened on the 2nd run at the track too. My concern is it might be a failed intake manifold gasket... I hope you can figure it out because at this point (even tho I've tested them) I want to start randomly replacing sensors, but it would be awesome to figure it out without all that.

Help us out guys!

[Carl H]

when was the last time the plugs were changed?

[Kansei240sx]

If you had a failed intake manifold gasket, it would have a really high idle.

[Joe]

plugs are about 2 months old.

[300Plus]

Im changing my plugs today, whats recomended gap again? and I will pay attention to my idle to see if its any higher.

[Carl H]

hrmm comp test the motor if you can, my may have dead piston rings or a blown hg...

[Joe]

Shouldn't there be other signs of that tho?

[Sil240]

Even better you should Leak Down Test your motor.Then you can find out exactly where it is you are losing compression from, if you are losing compression. I hope not.

[Joe]

Yea yea I know a leakdown is a much better more accurate test but I don't own a leakdown tester and hate doing them.

I'll comp test it and see what the numbers look like.

I'm really starting to lean twords fuel pump.

[wawazat8402]

Im changing my plugs today, whats recomended gap again? and I will pay attention to my idle to see if its any higher.

I believe the recommended gap for NGK coppers is .8mm

[Joe]

welp its not mechanical (headgasket or piston ring)

i pulled it off the trailer at work tonight so i can troubleshoot during the week. roll it around back and give a little run in 2nd gear. breaks the tires loose and feels stronger than ever. the only things i checked today were timing and the internals of the ECU.

im gonna pull my wiring harness out tommrow and check for breaks. this harness does have some ghetto things done to it from the previous owner...(original owner in japan)

[Carl H]

ah, it might be the fuel pump then...what kind are you running?

[Joe]

walboro 255lph.