Hey guys I'm a first gen guy so I have no clue about the ISB engine. My Dad has a motorhome with the ISB and he sent me an e-mail saying that he is losing power really bad. I suggested that he check his lift pump and vp44. All checks out well. Someone suggested to him that it could be the turbo sensor. I've never heard of a sensor for the turbo. Is there any such thing? Any suggestions on what to check? I just told him today to check for boost leaks. Any other ideas? Thanks guys!!

Jeff

 

The closest thing I can think of to a "turbo sensor" is the MAP sensor.

You are right to look for boost leaks. Any codes at all? Hopefully someone with more knowledge will post.

 

You said his lift pump and VP44 check out......but what about his fuel filter?

I have heard over and over again about guys losing power with their trucks.......then they change the fuel filter and all is well again. It's easy to get a bad tank of fuel.

 

Turbo sensor??????????????????????????????????

HHHHHHMMMMMMMMMMMMMM

Maybe the electronic blow off valve???????????????????

 

Ok I finally got to talk to him directly and he said that he changed the fuel filter and air filter. He said that he can't hear the turbo spool up at all. I don't know much about the newer turbo set-ups. I heard that some of the newer ones are variable somehow but I've never looked into how they work at all. Any info would be appreciated or if anybody has any more ideas. Seems to me that if he has fuel the turbo should spool up

 

He can manually work the wastegate and make sure it isn't stuck or something stupid like that. If it isn't then the turbo should be working ok unless he has a boost leak or the turbo is shot. He can take the intake tube off and spin the impellar. If it spins freely then I would say that parts ok.

No power usually means fuel pump, fuel filter and/or injection pump. A fuel pressure gauge would go a long way here I would think.

 

Depending on the year of the ISB engine,& whether it's a B,or C series,It may have a VG turbo.It will have a lever on it verry similar to a waste gate.& a sensor on the outlet side of the turbo.It may be stuck open.This will cause the turbo to spool up slowly but it should still spool up.It sounds to me like the turbo is siesed up.Make sure that the turbo spins freely.Good luck.

 

I had a MAP sensor issue on my truck, was lacking power, changed the sensor and viola turbo was spooling back up again just like new. There should be two MAP sensors, one near the airbox (Ambient air) and one (depending on the year) on the intake manifold (boost sensor).

 

Thanks for the replies. I'll pass all of the info on so he knows what to look at. Thanks again!