afpreppie04

iTrader: (5)

So after getting towed home yesterday (turned out to be IC coupler blew off, but couldn't check/fix it at the intersection very well), I put the IC coupler back on and it started up like normal. However, today when I started to get in boost it acted like fuel cut, really jerky. This was at about 3 psi. After some testing I found that if I gradually get in the boost it can still go, especially in 3rd, 1st and 2nd are more touchy. I did search but there are answers coming from all over, from TPS to vacuum leaks to nipples blowing off. I checked all the nipples and couplers and they are all normal. I am leaning towards TPS, since when I reassembled the engine a couple months ago I tested it and it was off, I have since picked up a spare so I can swap it in, but why would it do this all of a sudden when the IC coupler blew off? Just coincidence?

Is there anything else it could be? Drives just like normal out of boost and its not the 3800rpm hesistation, I can go over 3800 no problem as long as I am out of boost.

Mods are: 720 secondaries, Rtek 1.7, 3" turboback, intake, walbro, TB mod, emissions removed, wastegate ported. All new fuel hosing and filters, and all injectors were cleaned. Still using TMIC for the time being.

RandomHero

iTrader: (2)

well, being that this happened after you blew the pipe off, I can only think boost leak. How much boost do you usually run and how high did it get on your test drive?

afpreppie04

iTrader: (5)

I usually run 10 psi and during the test run it got up to about 9 in third with no bucking, just have to sort of ease into the boost.

afpreppie04

iTrader: (5)

Ok, update. Got the problem fixed. I first adjusted my TPS, which, while being out of spec, wasn't the culprit. Next I went through all the possible boost leaking areas and tightened down all the couplers, and got new couplers for the intercooler hoses, where I had simply reused the ones before and they were leaking some. This helped some, but it would still buck under boost, particularly in first gear. Where it turned out to be leaking was the BAC hose to the aluminum thingy in between the IC and the compressor housing. These didn't have any clamps stock so I hadn't put any clamps on when I put it back together. However, when the coupler between the aluminum piece and the compressor housing blew off, maybe it stretched the hose opening a little or something. I put some clamps on both ends and presto! I have boost again.