First let me say have done a boost leak test and nada.

I installed my GM MAFT trans Gen II, Tial BOV and Hallman MBC about 2 weeks ago and have been pulling my hair out since.

I have a good AFR at idle, when I build any boost the AFR goes rich to 10 and it sounds like air is gushing out of my BOV. So I did a boost leak test from the turbo and nothing, Just to be on the safe side before I did the boost leak test I replaced all the worm clamps with t bolts clamps on the upper IC and MAF. Today I took out the hallman MBC and hooked up the stock boost solenoid thinking I might have a bad MBC and still the same.

I have also been doing my best to read about the tial BOV on here the past 3-4 days and see there are some deff problems with it, but they seem to be related to people doing VTA with no MAF control, plus my MAF is up by the TB so I should be ok. I also see a lot of people say put your stock BOV back on, no can do for me as I have this UICP flanged for the tial.

I would log to see what’s up but someone decided to break into my car and ****** my laptop (waiting on a new one from dell).

I am now at the point where its been about 2 weeks I have been trying to figure this out and I am getting sick of driving my 4G Eclipse !! HELP PLEASE!

BTW I have the BOV line connected to the intake manifold.

Thanks

 

having the line hooked up to the intake mani is the problem...its not putting pressure on the bov when you hit boost...its actually sucking in...you bov should be connected with the boost controller and wastgate etc...not off the intake mani..change that you should be good

 

I had tuning issues with the GM MAF as well. Put it back to stock, it is not worth the headache.

 

uhhh.....sorry but that is incorrect.

The bov is connected from the intake manifold from the factory......when you go into boost the manifold has positive pressure and is not sucking in (its being forced in). That would mean people who hook up there boost gauge from a source on the intake manifold would read vacuum even when going into boost according to your theory and that is not the case.

The main issue with people and tial's is they aren't setup for re-circ. which causes driveability issues on stock MAF cars.....You dont need to re-circ. because you have a blow-through MAF setup. You either have a faulty bov or your not doing your boost leak test correctly.

 

Thanks for the reply’s

I have done a little more since that last time I posted about this, I re did my boost leak test to 24psi and heard a small leak from the hose at the wastegate to my boost controller and fixed it. Next I pulled my plugs and it was foul city (I am guessing from when I first hooked up the maft I was super rich). Then I fine tuned the AF wideband auto adjusting at WOT with the genII. So I am now able to pull about 18psi-20psi of boost then here comes the air leaking sound and the boost stops there, it almost feels like fuel cut as my wideband starts to blink 10.0.

So I am in the hard place between it could still be a small leak that for some reason I cant hear when boost leak testing, the bov is opening to early, or I need to tune some more with the GENII.

NOTE: I took my MBC off and put it on my friends EVO to make sure it was set right for 22PSI my goal max boost for now.

I like the MAFT setup a lot because the turbo spools sooooo muuuccchhh quicker, I just need to work out the gremlins with my boost. I hope to have my new evoscan cables tomorrow so as soon as I get a log ill post it but in the mean time any help is much appreciated

Thanks