gtracer

Just did some maintenace on my 88 951 ..181K miles...repaired the hose to the wastegate, belts, hoses etc...the car was cutting out before and found the hose on the wastegate cracked ...
the car is running smooth...max boost on the gauge is 1 bar(factory guage)...I put a locking plier on the wastegate hose and got 1.8 on the guage and it runs great...is it the wastegate or the cycling valve...is there a way to diagnose one or the other...thanks...

Andy

If you get 1.8 by clamping the line, the wastegate is still working, actually you're lucky you didn't get more than that but it is a high mileage wastegate. I'd say check the connections on the cycling valve, it will default open when it loses power or breaks. That ususally results in 1.2 bar indicated as a max but the guages aren't very accurate. My second piece of advice is spend $30 and get a real boost guage, they're almost worth their weight in gold for several reasons. Good luck.

gtracer

Thanks for the advice...a boost guage has been ordered and a new valve...what should the stock guage show on a healthy car and what does that translate to on a real boost guage....thanks again

Danno

Max-boost on the stock gauge should show 1.7-1.8 bar which is about 11-12psi. The manual actually says that 9-12psi is the norm.

Sounds like you have a bad cycling-valve. Its default mode is to send all pressure to the wastegate, thus opening it and dumping boost. Only when it receives a signal from the KLR does it divert pressure away from the wastegate back around to the intake. Then you have boost.

gtracer

thanks , I have a better understanding...of what is going on ....thanks Danno...