I would say it needs a booster? does it hiss when you step on the brakes or anything? brakes feel overly mushy? Could it be something wrong in the tune file like the in gear op temp idle too high? Need more detail I think

 

The truck was running perfect right after the tune and half the day after. I drove it around today and the brake booster message didnt come back on just had a really high idle. The brakes feel fine on it too.

I took my wastegate apart and found a little cut in the rubber. Its really small tear that looks like it was worn out by the bolt that hooks up to the vac line. Is this rubber servicible or does the whole wastegate need to be replaced?





You guys think this small tear could be the cause of my high idle? I always thought that vacuum leaks make idle drop instead of increase?

I still get about 17 inches of vac at idle and before i got about 18 or so.

 

vacuum leak increases idle speed, think opening the throttle body.

 

Well **** i blocked off the wastegate and its still doing it.

I'm ordering the new diaphragm so i blocked it off for now. Started it up, idled fine for a few minutes, took it out for a drive and it seemed good. Pulled over and shut the engine off. When i started it back up the idle shot back to 14-1500 rpm.

It seems to be intermittent. I was driving to work and at the stop lights i would switch it into neutral to see if the rpm's rise and sometimes they did and other times they didnt.

What else could be causing this? I sprayed down everything and did not find any vac leaks. I'll have to pick up another can of brake or carb cleaner after work and see if i missed anything.

Is there any way of checking the brake booster to make sure it is working properly? I unhooked the hose from the brake booster and put my thumb over it and did not notice any difference in idle.

 

BTW I also get P0507

 

That little electric pump that is mounted on the brake booster is there in the event the engine shuts down it is supposed to give you emergency vacuum boost to the brakes if I remember correctly. I know my buddy with his procharger killed one of those things a while back. Never really quite figured out why. But we isolated that to be the problem. Similar symptoms as you are posting might be worth a shot

 

I will call the dealership to price one out tomorrow. I capped everything off on the intake and it still does it. I sprayed the intake down with carb cleaner around the gasket area and all over and saw no difference. So I'm not sure what could be going on. I'm going to go out and clean the maf but i'm all out of ideas.

It seems to be related to the coolant temp. It seems that when its around 170- 200 it starts doing it but if i'm cruising for awhile and it cools down then when i come to a stop it doesnt do it.

Could this be tune related somehow?

 

Well the maf looks clean. I was expecting to find some oil or something on it but it is dry and looks fine. I cleaned it anyways but i dont think that is my problem.

 

Yes, could be very much tune related. There is a table in the PCM for Required Airflow while idling based on coolant temp (B4307 in EFILive). If your tuner messed with it, he could have got it too high in the higher temps and it would do what your saying it's doing.

As for the WG Boost ref point you asked me about in your PM, every turbo I have have ever setup was ref off the intake manifold...

 

Thanks for the info. I noticed that my maf sensor is a little dented from the intercooler piping. Do you think this would affect anything?