Miss-Fire past 5 psi ???

[PhiDelt109]

The Car Misses like crazy if I try and boost past 5 psi. I hooked my MBC back up and then it will boost trying to push the motor untill I popp an IC pipe, while missing after 5 lbs still. Car has boosted @ 11psi just fine before.

LexAFM/550cc's/intake/full exaughst/NKG's ....etc

1. Is it fuel cutt?? Its not like Power--NoPower--power. Its like Rev Limiter feel.

2. Doesn't seem to be a boost/vac leak either. As MBC = Boost > 5psi

3. Is timeing being pulled due to detonation perhaps >???? TCCS ??? How to tell

4. I checked the timing and it was off ALOT ????? It did run well ??? WTF ?
So I set the timeing correctly. Jumpered, -10 deg TDC

The only codes EFI is getting is speed sensor and the occational 52 and I can feel it. Code 52 is a bad wire.

Minus the rough starting the car has good power but will not boost past 5 lbs.

I have recently replaced R154, knock sensors, wired up the front VSV looking thing with a round dial on it. Previously the rear KS was broke off for years it looks like and the frnt VSV wires were cutt and the car boosted fine, so the problem shouldn't be there.

ANY help is greatly appreciated guys.

 

[Bishop92t]

Code 52 is knock sensor which will definitely make the car run slow. But until the CEL comes on you should have normal power. Really it sounds like a boost leak. I don't know what turbo you're running, but with the Lexus you should be able to hit much higher then 11psi. Check the IC pipes from the turbo to the intercooler and the 3000 pipe to throttle body connection.

 

[PhiDelt109]

^ Thank You, I will double check the pipes. HEY, ma70.com partly inspired me to get this beast 1.5 years ago when I had this 87t offered to me! I think I emailed you about my car like the 1st week I had it.

 

[theDon]

I had a simliar issue and was told to go from NKG to copper plugs.

 

[PhiDelt109]

^ Got NKG's already but who knows. Thanks for the input

 

[rakkasan]

Check the IC pipes from the turbo to the intercooler and the 3000 pipe to throttle body connection.

I can't count how many times I've read that within your posts. Did you save it somewhere so you can cut-n-paste it?? :icon_mrgr

 

[Bishop92t]

I even wrote a thesis on boost leaks http://www.ma70.com/bishop92t/techtips/boostleak.html

 

[drjonez]

check your plug gap.

code 52 = no timing advance, hence the lost power.

 

[PhiDelt109]

^ Hummm the knock sensor was broken off for a long time, the timing was way off.
I bet the previous owner attempted to compensate the lack of a ks with the timing

 

[PhiDelt109]

The car had no WOT problems before