Hey guys, truck has been doing this for a while now and I'm just stumped. Truck has had a rear mount turbo setup on it for around 1k miles before the problem started. When starting the rpms will shoot up to around 2k then work there way down to around 400rpm. It will idle fine for a few seconds then will start to hunt for an idle. Sometimes it dies sometimes it doesn't. When driving it seems like the thing will cruise 30mph without even putting your foot on the gas. If coming to a STOP while in drive, it will come down to a normal idle for a few seconds then start to hunt /surge and may or may not die. VERY ANNOYING. Tried a brand new throttle body AND a brand new MAF with no avail! Someone help me out guys lol

Thanks for any input!

 

It sounds like a vacuum leak to me from what you are describing. Do you have the ability to log data? If so, what are your fuel trims saying? Check all connections real well to make sure you don't have a hose leaking.

 

Thanks for the response man. I thought it may be a vacuum leak also but my boost guage reads 18 bar or so. I can log data using my torque app on my phone but don't know exactly what I'm looking for. Thanks.

 

Just took a loop in the truck to get some readings. After it was warmed up, I checked the fuel trim bank 1 and bank 2 longterm and they showed no signs of a vacuum leak. They were all around 0. Any clues?

 

I know you said you replaced the Maf, but have you tried unplugging the MAF to see if acts the same?

 

FastBrick,

Actually i never have tried to unplug the MAF. I wont be with my truck again until Friday but i will try that for sure.Will I know not to even attempt any kind of boost with the MAF unplugged, but can I run it long enough to get it up to operating temps with it unplugged?

Also here is a vid of the problem. If i sit in "Drive" long enough at a standstill it will eventually start to surge also, but putting it it Park makes it almost immediate. As you can see in the vid when i went back into "Drive" it caught itself , but that doesn't always happen. Sometimes it will continue to surge until you give it any throttle.

Thanks for your time

 

Daily Bump.

 

When you unplug your MAF, stay out of boost..... NO BOOST

 

Will do man. Any clues from watching the vid? ever seen that? lol

 

Are you able to post your tune? I wonder if it is your idle airflow. Try putting it in neutral and see if it responds the same.