gmsracing

Well, I've been chasing a boost problem for quite some time now. It only boosts to 1.8 on the stock gauge compared with the normal 1.95-2.0 w/ Authority II chips. Then when I rev out 2nd gear it would go into safe mode. The car is noticably slower and unresponsive at 1.8 bar. Spool up time seems longer also. I bought the LED from Radio Shack but I couldn't get a reliable blink code from the port. I think today on the way home from lunch I was able to consistantly read a 3-1. Isn't it fun to do diagnosis problems on the way to work? Anyway, it means charging pressure too low. So based upon the manual I need to check to see if the wastegate is stuck open, if not then the timing valve, and finally the klr. I replaced the timing valve withing the last 6 months so I don't think that's the problem. I do have a spare klr I'm going to throw in tonight to see if that fixes things. If it is the turbo, then it will be easier to convince my wife of the "logic" in investing in a new Lindsey package!

reno808

haha i know how that is

gmsracing

I did some more diagnostics this weekend. I checked the wastegate dump pipe at cold idle to see if it was leaking. The pipe didn't get warm. I pinched off the wastegate vacuum line and it made full (1.95-2) boost. So that led me to the next step of replacing the klr. I replaced the klr and the dme and now I'm not getting the safe mode trip out. It's running fine but it still doesn't seem to be making power. It also doesn't seem to be revving quickly or pulling nearly as hard in the high rpms. At this point it feels like a clogged cat, a colapsed downpipe, or low compression. I'm going to pull the cat and then drive it and see how it feels. This kind of reminds me of when my cat was clogged on my GTi...

reno808

Try it

Rip It

I read that 1.2 bar was the klr safe cutout mode. Is that right or is it different ? Is your BOV bypassing turbo pressure, its a quick easy thing to verify.

nize

1.2 bar is the safe cutoff mode.

if you have a lindsey boost enhancer (or reliaboost) installed, it will cut off at 1.8 bar, making diagnostic more difficult.

i'm curious, what's the easiest way to check the bov is operating correctly?

emwporsche

^ blowing through it

nize

okay, i've tried blowing through it. air escapes through the top nipple, but does not escape through the bottom (back to intake).

i don't think i could blow +12psi (or whatever the bov pressure is) to see if it actually opens.

btw, do you have an extra known-good bov i could borrow for about 10 minutes?

samluke

I had exactly the same symptoms with my car. See thread TurboS power loss. Mine turned out to be a bad KLR. I am convinced it was damaged when I had to key the car off to reset the ABS, when I was in a race. Looking inside the KLR you can see overheated components. Mine had the same symptoms, it was low on power even with high boost levels. I found mine by running on the dyno. Open up the KLR and look for overheadted resistors. I have looked at a couple of bad KLR's and they all look similarly damaged. I have since modified my ABS circuit so that I can re-set it.

nize

i've checked the dme+klr and they seem fine. i've also tried swapping the chips with known good ones without success. is it possible for the klr itself to get fried without damage to the chips? hmm...

samluke

I never tried changing chips around. I borrowed a good KLR and it fixed the problem. I opened the KLR to see what was wrong, On mine there were three overheated resistors. I changed them out but it didn't fix it. I had another with the same reported symptons (flat above 4,000RPM) and the same resistors were overheated. Its not clear what takes the hit in the KLR. There are a bunch of IC's in the KLR not only the control EPROM that could have been damaged by the same surge. Its worth opening your KLR box, The resistors that get overheated are on standoffs R125-128, there are also a couple on the chip board that take the hit. I think if you see any overheated components then your KLR is fried.

emwporsche

I have a bov you can borrow nize, you have a pm

nize

thanks, it turns out it's not the bov.

Trucho-951

I've read in other threads that ignition timing can be retarded by the KLR as it communicates withthe DME. Why would the KLR do this? Well, in addition to inappropriate A/F ratio, if there is exessive oil in the intercooler pipes and/or intake (bad turbo seals?), then pre-ignition in the combustion chamber will occur, and the knock sensor will be sending signals to the KLR to retard the timing.

So, even if one were to re-establish boost by pinching off the signal to the wastegate, the timing would not be restored untill the KLR decides it's ok to do so.

Rip It

Nize the diaphram/seal in your BOV is bad if u can blow air out the small nipple.