knotsonice

iTrader: (2)

hey all. So 99 twins in simplified seq with AzEknights solenoid kit. Has been working rock solid for over a year. Yesterday Driving home from work I get on it a bit. No boost. So i slow down to 35 leave it in 3rd gear and floor it. 0 psi all the way to 7500 rpm. When i let off i usually hear a psst from the BOV. But i got what sounded like a wet fart. I looked at vac lines last night. Didn't see anything out of the ordinary. But what else could cause a complete loss of boost?

Thanks
Carl

RuffRx7

One big *** boost leak, do you hear hissing when you accelerate?
Check to see if there intercooler piping hasn't come loose.

DaleClark

iTrader: (55)

Yep, boost leak. It doesn't take much to lose all boost.

BOV connections, intercooler couplers, ANYTHING in the air path from the turbos all the way to the throttle body.

Dale

H_M

iTrader: (7)

Sounds like a big boost leak. I found the coupler to the Y-pipe can slip out sometimes if you have an earlier Y-pipe.

knotsonice

iTrader: (2)

i was getting 1-2 psi this morning. I don't hear any hissing. '99 y pipe and all aluminum pipes. 4 couplers (elbow to intercooler pipe to intercooler) (intercooler to pipe going to y pipe). All 4 are solid no splits. I'll pull them all off tonight and reset all 4. I have always heard the turbo's spooling but nothing that sounds like a boost leak. Like a said only weird sound coming off full throttle is that wet fart sound instead of that quick PSST from the blow off valve.

DaleClark

iTrader: (55)

If you have enough of a boost leak, you won't hear anything. There's no resistance, only a restriction or a resistance will make any noise. Also, with no boost going into the engine, it lowers the exhaust pressure to drive the turbo, making even less boost - it's all a system.

Another possibility is the throttle not fully opening or sticking.

Dale

knotsonice

iTrader: (2)

Well i broke 2 of the clamps.. Have new t-bolt clamps all around now nice and tight. Inspected the couplers and all 4 are good. Inspected/removed all the hoses for the BOV's all are good. Went for a drive same thing. no boost. How do i test the bov's? that sound is what has me thinking it's one of those.

DaleClark

iTrader: (55)

You need to do a boost pressure test. There's tons of info on how to do it, here's a video -


Pressurize the system and look/listen/feel for leaks.

Also possible to have a major exhaust restriction or a wastegate that's wide open or not connected.

Dale