Turbo Problem

[Sago Rey]

MY 97 CK350 with 155000 mi has had this problem of the turbo not wanting to work, somtimes(almost all the time) after it had worked just fine for an hour or so usualy when towing. I will shut it off but when I start again the turbo wont work. My tec changed a sensor that B&D thought might be bad, did not fix the problem. He spent quite a bit of time trying to trouble shoot the problem. He decided that the problem was with the B&D coumpter that I had instaled 14 months earlier.We ordered a new computer through B&D but I still have the problem, although this new computer gives me better performance then the first so all was not lost.The turbo always works when cold. Then the shop said the problem is probaly caused by blow by Fowling a sensor. I burn very little oil 1 qt. in 3000mi I dont smoke mutch the cat is removed so if I had a lot of blowby you would think I would see it.Of course I smoke When I put my foot into it when the turbo is notworking. Where do I go from here Does any one have any suggestions Regards Sago Rey

[ronniejoe]

Do a search on "low boost" in this forum. You will turn up much on the factory boost control system. You must ensure that the vacuum system is working properly. You could have a bad Wastgate Solenoid or leaking vacuum lines or bad vacuum pump.

[JohnC]

One common failure mode for the wastegate solenoid is to stick when hot. If nothing else shows up, I'd try replacing it. Make sure the vacuum pump is healthy first, though.

[DA BIG ONE]

I went crazy with mine too, it turned out to be a damaged harness where it comes into interior on pass side foot area between the blower motor and the evap core box. It hangs down so anyone sitting on that side would make contact w/it w/their feet. Found pins/wires pulled out of first plug that goes into computer too.

I did bypass harness for that circuit and use a resister at the computer now 50 ohm 10 watt, and use a turbo master.

[Kev-o]

the waste gate rod was bail wired open when i got my 98, I guess they thought it was bad, so i checked the lines for vacuum and found not at the waste gate and none to the solenoid replaced the vacuum pump and cut the bail wire off it's now like a new truck.