KA-T "buckles or kicks" when in boost...

[Bosrudorfer]

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Modified by Bosrudorfer at 6:53 PM 1/29/2008

[Bosrudorfer]

I forgot to mention I have the check engine light on and the following error codes showing up. These too have been there since I got the car turboed.

PO136 O2 Sensor Circuit Malfunction Bank 1 Sensor 2

PO446 Evap Emission Control System Vent Circuit Malf

[Zippy69]

Really sounds like a maf issue. You could check your coolant temp sensor.G/L

[boznuttz]

What size turbo do you have? 10 psi on a T3/T4oe 50 trim and an exhaust a/r of .63 or so will easily max out the maf.

Could be time for an upgrade, since your MAF is only good to about 250 or so to the wheels.

[Bosrudorfer]

Thanks for the suggestions fellows. I'm running the JGS kit so its the AGP/Turbonetics .50 trim T3/T04E turbo (.48 A/R)

I believe I'm making around 240whp so maybe it is time for a bigger MAF. Some 555c injectors too

[s13rb25det]

knock sensor mabye?

[Florida240sx]

CTSSpark plugs... maybe wore out or gapMaf maxing out can you turn the psi down for a few test runs?

[steve s14]

I would agree that it sounds maf related, i would check the connector to the maf as well.I would also double check the connections at the emanage harness.There are a lot of places where it taps into critical ecm wires.If the connection comes loose there, it can cause strange problems to crop up due to the signal becoming degraded.

[WDRacing]

O2 sensor? Had that happen to my S14...O2 wire got chaffed through. Also check for IC coupler leaks.

WD

[C-Kwik]

I doubt it's the MAF maxing out. If an when the MAF maxes out, the injectors will likely be at 100% duty cycle. This would not cause such an abrupt change in acceleration. My guess would be the spark is being blown out. Check your plug and gap.

zerothread/301766

[240FeVeR]

Exact same problem used to happened to me on my old car (ka24e)...engine would buckle and i had to let off before i could accelerate again. Turned out to be a bad spark plug wire, there was a small hole allowing the spark to get out onto the valve cover. Give it a check.

[Jookmasta]

i could place a large sum of money that it is your gap on your spark plugs. i had the same issue................

solution: buy some new plugs, gap them down even lower than the current gap your running and watch your car run beautifully again.

[egan]

i know this is silly, but check the grounds too. my car was buckling under boost and it turned out i hadnt tightened the ground wire bolt on the exhaust side of the head all the way....