hey guys. seems like im having issues with the truck once again.. lol

it started when i took the truck to the track when i could actual feel it. it started out the truck would slightly hesitate at 4500rpm then pick back up. so my tuner logged a few passes at the track... come to find it the slight hesitation was the truck was pulling *5 timing at 45000rpm, so it was only at 12* timing, hince why i could feel the loss of power for a slight second. at idle it was showing the truck was running 7% percent lean in bank 1 i believe.. im not to sure of which bank its been awhile. anyways the truck progressive got way WORSE!!

i understand this can be a number of things, but ive narrowed it down to a exhaust leak or vaccum i think... thats why i came here to run this by you guys to see if you can help me out, i can destinctively hear a sucking/hissing sound coming from UNDER the truck.. anyways the problem with it now is under any kind of throttle light or heavy the truck with stumble and fall of its face like its pushing the peddle back at you, and the wideband with go straight lean (no numbers) truck holds boost just fine.


any suggestions on what it could be? or sound like? i know my description isnt the best, but its the best i can do over the internet lol

Thanks, mike

 

possibly a PCV hose come loose?
thats the first thing i thought of..
your tuned with the MAF, right?

 

pcv is completely gone, vented to atmosphere with breathers on both valve covers. checked all nipples on valve covers, intake etc.

and yes i am tuned for the maf it was always throwing the p0101 code.. but my tuner said it was maxing out the maf, so when it did max the maf out he would just have go into speed density etc..

the truck just started doing it and its getting worse day by day. i would think it was something major, but its the fact i can hear a distinctive hissing/sucking noise from under the truck that i have never heard before untill this happened.

also i took the wastegate off and the actuator or valve is strong and you can push it down. its not stuck open or closed etc.

 

I read a post yesterday of a guy dealing with some similar conditions... His was a faulty maf. It was a recently turbo'd lifted red ext cab truck.

 

I wanna say it's the MAF, but I'm gonna have a fog test done on all intercooler piping and vac lines just to see if I have a vac leak or exhaust leak.. Cuz I can hear a hissing/sucking noise coming from under the truck I've never heard before.. But it you can't hear it at idle

 

Are you running o2 sensors? Could be a bad one...

 

Yeah I'm running o2s. Don't have a code from them.
A little update tho, the hissing sucking noise is comin from the wastegate. It's very loud. Cud my wastegate be bad??

 

Could have a damaged diaphram and its sucking vacuum.

 

It proly is. It's a crappy jgs wastegate. I have a tial on order to hopefully have fixed the issue. And vac lines check out good

 

Jgs wastegates are not crappy. Ton of ppl on here run them. Make sure the flex joint going to the gate is not blown out and leaking. Mine did this recently...made a similar noise you were describing...