Wanted to get some opinions on what could be my issue. I have awful fuel mileage, surging, rough idle, but only when cold, motor stops pulling at 1700rpm, and my turbo always sounds like it’s building boost. I’ve done a lot of reading, and all my reading brings me back to one thing, turbo actuator. I have an older CM870, and I don’t think it will throw any codes for the actuator always being closed. I just replaced the CAC and don’t have any boost leaks. TIA.
Anyone? Rather not throwing money at an issue to guess and check.
Well your correct in there's no monitr on the actuator of a 870...best you can do is hit it with 60 psi shop air and measure the travel and make sure it isn't binding.
EGR problems can do this too but you would have a CEL.
The surging and rough idle also point to injector, fuel issues, fuel system issues, and fuel actuators. Id have a good look at all of it.
Truck has been demandated, but not tuned yet. Haven’t looked into who to have tune yet. I’d also like recommendations on that, if anyone could give any input. I did buy the plate to check the injectors, and a dial indicator to check the timing actuators. I don’t want to put a lot of money into this engine. It already has almost 1.2 million miles on it, and I don’t plan to inframe it. I was quoted $24,000 at the low end for an inframe, and don’t trust any smaller local shops. They won’t even diagnose the issues I’m having now. I just can’t afford to run a truck getting 4.78mpg. Thanks for all the replies. I’ll update once I do more diagnosing.
I’ve never seen the VGT actuator move. I moved it by hand and it knocked rust off the turbo, I know that isn’t a good sign. Does the actuator hold the canes normally open, or normally closed? I know if it was normally closed, I’d always be making boost, and won’t get any fuel mileage.
If it's demandated that means it's tuned. Who did it is the million dollar question. That could be your problem right there. Before you go any further you need to get a copy of that program over to Rawze for review.
(02-20-2021 )Hgilp Wrote: [ -> ]...
Truck has been demandated, but not tuned yet.
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Is there a check engine light on in the dash for the egr valve or other devices being unplugged then?