I've been trying to solve my boost issue since I got my car. Car will boost- everytime it is restarted, then will go into "protection mode" after a couple of boost shots (1.2 bar on the factory guage). I've run out of ideas....
I replaced TPS, replaced KLR, removed and tested knock sensor (reads 300K at sensor and at KLR plug), redid engine ground wires, cleaned every sensor connection I could find, read hours and hours of the archives on here, not sure what to try next.

Car has Autothority Stage 2 chips. Tried another KLR with factory chip, same thing, put in the Autothority chip ,same result (with more boost for that very short time...)

Any ideas?

Mitch

 

I'd say the first thing you need to do is get a real boost gauge. 1.2 bar on the stock gauge is only about 3 PSI boost- you won't even feel that. If the car feels any faster than an N/A, you gauge is probably way off.

My guess would be that it really is overboosting, could be a bad cycling valve.

 

Are you still getting the same blink/fault code? From your previous posts, werent you getting the 3-3 code?

 

I haven't checked yet, my little LED tester I made broke a lead, I'm going to make a new one. I read in the archives that the Autothority chips could cause fault codes, even though they are working fine. That sound right? The problem is exactly the same, even after replacing the KLR.........

Mitch

 

checked wastegate?

 

+1

It sounds like your wastegate isn't opening - either because it has a torn diaphragm or because of a bad cycling valve. I would check those first (and make sure the system is working properly).

For those interested, the cycling valve is normally opened, allowing manifold pressure to go to the wastegate. When you are building boost, the KLR triggers the cycling valve to close which then closes the wastegate - building boost pressure faster than a 1/2 open wastegate.

Here's a video showing how the cycling valve actuates - I wired a buzzer in-line with the cycling valve control wires, when it buzzes, the KLR is sending electricity to the cycling valve which closes it (and indirectly closes the wastegate):


Note: my car had a different problem - it was going into "overload protection" - not "over boost". "Overload protection is when the feedback values from the air flow meter and the TPS don't jive with each other, so the DME thinks the air flow going through the AFM doesn't equal the air flow going through the throttle body. The DME cuts fuel and spark to try and "save" the engine from an unsafe situation.

As I was typing this, it also occurs to me that it could be an incorrectly adjusted Lindsey boost enhancer, if you have one - or a banjo bolt with too small an orifice. Again, these would prevent the wastegate from opening.

 

Checked the line from intake to KLR, it is not leaking. Cleaned connections on cycling valve. Checked and reinstalled knock sensor. Car will make boost, so it's there, but limits after a few shots of it. I plugged in my old KLR with factory chip, and put in a stock banjo bolt (still had the Autothority chip in DME, don't have factory for it), which lowered boost, but still went into protection mode just the same.

Made a new LED tester ,and can't get any codes at all, tried unplugging the TPS which should set one, but got nothing. Lindsey racing and the RacerX sites both have info for hooking up the LED test, but show different connections on each site, I can't remember which is right..... Tried both, got nothing.

Now upper radiator hose just went while I was testing.........might have another 951 up for sale soon on here........