Phil Harrison

OK - here's the story so far....

1988 951, purchased at 66,000 miles, installed Europroducts chips, wastegate shims & Lindsey Boost Enhancer - gave 1.9 bar boost 100% of the time, but seemed always to run rich, as witnessed by sooty exhaust.

On Saturday switched to used AutoThority chips (marked POR.01.951.220 s/n 100). Car gets 1.5 bar 80% of the time & 1.9 bar the other 20%. On 1.9 bar the car seems quicker than before, but at 1.5 bar the car is a slug...

Can anyone explain what is happening here??!! <img src="confused.gif" border="0">

Toolmaster

Did you use the autothority banjo bolt, in conjunction with the Boost enhancer?

If so - put the stock banjo bolt back in...

HTH!

Jeremy Martin

you cant really trust the boost gauge unless it's an aftermarket one. the chips affect what it is showing; the chips could also be telling the wastegate to open to match the stock fuel curve (which expect the turbo to lose boost near redline)... with that said the autothority chips retard the hell out of the timing (even vs other brands of chips) so 1.5 bar with the autothroity will seem much slower then 1.5 bar with other chips.

Phil Harrison

[quote]Originally posted by Toolmaster:
<strong>Did you use the autothority banjo bolt, in conjunction with the Boost enhancer?

HTH!</strong><hr></blockquote>

No AutoThority Banjo bolt - just the LBE.

Dan87951

I had this problem as well turned out to be a cold solder joint in the KLR computer. When ever you get 1.5 of boost push in the clutch shut the car off (to let computers restart) then re-start the car I bet it will boost to 1.9 bar. My car was doing the same thing and evertime I shut the car off and re-started it,...it would boost to 1.9 bar, further diagnostics found out my KLR unit had a cold joint. Ever since then I haven't had a problem.

Phil Harrison

[quote]Originally posted by Dan87951:
[QB]..turned out to be a cold solder joint in the KLR computer. ....push the clutch in & shut the car off (to let computers restart) then re-start the car ...my KLR unit had a cold joint. QB]<hr></blockquote>

OK to confirm...

When you get the 1.5 bar boost, stop the car, press the clutch in & then switch the ignition off.

Is this an undocumented ALT_Ctrl_Delete sequence???

How did you find the cold joint in the KLR? I assume that you just used a soldering iron to fix the problem?

Thanks for the feedback!

Dan87951

Yea you can think of it as a ctrl-alt-delete type of thing. I just started re-soldering everything on my board and after that it never did it again. I notice everytime the car would not boost was when the car was still cold and not warmed up yet, so a simple shut the car down and re-start it always cured the problem which told me something electrical was not right. First plan was to check out the KLR unit and it worked for me. While putting in the new Autothority chip you might have loosened a joint somewhere?? Worth a try. Good Luck!

Robby

My first guess would be the throttle position switch- mine did the same thing- I was using stock chips w/no mods though. The car would just go back and forth b/t low and high boost- at random- USUALLY low. It might get 1.5bar 50 times in a row and then, the very next time, full boost- my car was getting about 1.9 on the factory gauge w/out chips though- I think you should be hitting the full 2.0 w/APE and the larger banjo bolt...

Several people on this list have checked the stock boost gauge w/aftermarket ones to find the stock one was VERY accurate- I haven't found anyone who has said otherwise, other than making assumptions- It's problems are that it's hard to read (for instance, the 1.8 to 2.0 jump is a lot closer together than the 1.4 - 1.6 & 1.6 - 1.8, etc) and, it reads bars instead of PSI, which can make a big dif.

Anyway, I was advised over the phone by David Raines (Powerhaus) that my TPS was bad- my mechanic didn't believe it was really causing the random boost problem I was having- it turned out that David was right! Of course, now it seems like I'm getting about 1.8 all the time- before, when the boost WOULD come on right, it would be a little higher, and sometimes all the way on the 2.0- no one can tell me whether or not the TPS can actually cause it to do this, but it kind of makes sense to me- if it can lower the boost, maybe it can spike it up too- kind of all over the place(?)...