Help!

Ok so I've been trying to figure this out for awhile, and the dealer hasn't been able to pinpoint anything - here's what's happening:

Cruising in 4th gear, start going up a steep hill about an 1/8 mile long pulling about .1 to .2 bar. There is some noticeable hesitation when trying to hold a steady speed. If I hammer it, it takes off without any problems. I've got a durametric, but I'm not sure what to log to try and figure out what is causing this. Note, this doesn't happen while cruising on a flat surface. For some reason, I feel like its an intermittent vacuum leak - or could be something in the fuel system.

recently replaced plugs and coilpacks
EPL tune for 3 years, this just started happening about 8 months ago
no codes are thrown

Where should I start? Smoke test? Fuel Pressure test at an angle???

 

Same crap with me but when data logging select all cylinder miss fires and see if your miss firing i had a small leak that caused this in the back of the intake which took over 4 hours to get too.

 

How'd you end up finding the leak? Smoke test?

 

I listened to these guys on here and i kept on saying no way it can be and bam did a smoke and pressure test heck a smoke test found it that's how bad it was lol. It was in a bad place in the back also diverter hose was leaking so try that first its the cheapest.

 

Did you do the smoke test yourself? Any tips?

 

No went to a shop to get it done. It's pretty easy just take your intake air box out and the smoker will block it then check for smoke around the engine bay.

 

Pressure test from the turbos to 20 psi ... must hold for 30 seconds...
do this and you will find your issue

 

Hey marski u said u have a kit for the pressue test? For sale

 

What's the best way to get to the turbos? Do I need to block the other turbo off when I do this test?