Tibminn

Ok, my car is having major problems, all of which are beyond me...

I finally got all of my turbo stuff installed today, start it up, and everythings working just fine. or so it seemed. Rev it up a bit, bov sounds a lil bit, and then the idle drops way down, bogs, and almost dies. I eventually figure out that the 1st gen dsm bov is the source of this problem, under any amount of vaccuum it is open a bit and the air the maf read is not getting to the engine. Put your hand over the opening and wallah! problem solved. I might pipe it back in, but i thought for sure people had run them without recirlculating. can anyone help me here with how to solve this problem? (preferable without recirculating since it would be kind of a challenge with my setup)

Well after we figured that out, it was time to take 'er out for a spin. give it some gas and everything appears to be running fine. Eventually get on it a bit and get the boost pumpin. goes up to ~3psi, everything seems good. step on it again, starts to pull pretty decent then WHAM! fuel cutoff or something... right at about 4.5psi. felt like i hit a wall. I looked over all my stuff again and it seemed fine. I thought maybe it was a fluke so i took it out again and same story. I have no idea whats going wrong, everything seems perfect. no CEL's either.

My fuel setup is only a gsx pump and a vortech 12:1 fmu. Its not much, but it has worked for several other people. alex01tib is the most recent example. Seriously what could be causing this!? maybe a faulty fmu?? I thought maybe injectors, but they are supposedly good up to 8psi, and for sure more than 4psi...
Would the placement of the IAT or MAF make any difference? I wouldnt think so... but i also wouldnt really know and i have no idea what it would be. Im super bummed and even more stumped... PLEASE help!! Thanks

SwiftTiburon

Omg lol dude thats basically the same thing that was happening to my tib. However, instead of my fuel cutting off at a certain psi it would happen at around 3500-4k rpm. Also felt like the car was hitting a brick wall when that happened. I put in a dsm fuel pump in there but still did the same thing.

I havent driven my car in a while so Im not sure if it does the fuel cut off thing still, but I know that my dad had to clear my cel's (cause i had a lot) and then move the IAT because it was way to close to the engine bay and that was causing some problems as well. My dad said after he did those two things the car ran great. Is your MAF at least a foot away from your turbo? If not then it could be giving you incorrect readings as well causing some problems.

My blow off valve isnt recirculated, but honestly, I know it has to be or else it wont work. With my bov, if you put something in it for it to stop opening and closing at idle it works fine and I dont stall. I was told I just need to recirculate..and trust me I have minimal room in my engine bay too.

I dont know if I even helped you at all but if I did, even just a little bit, then great lol. smile.gif

Good luck.

Tibminn

do all bov's leak like that or only the 1g dsm? Im thinking I might just try another bov.

And if what you say is true swift, maybe my maf and my iat DO have something to do with it. Im kinda doubting it tho because you said you had CEL's and I dont have a single one...

Here are some pics to ponder:




(yea I know its dirty... its winter and minnesota... 02.gif )

Alex01tib

OK this was the exact same thing that happened to me. around 3k rpms the car would just, as you said, hit a wall. Try unhooking the vacuum tube to your FMU, thats what i did and it boosted 5 pounds fine. I know this wont make the FMU alter the fuel pressure but if you set your wastegate to 5 pounds and try this and it solves the problem then you know its the FMU, it solved the problem for me and i havent attempted trying to hook it back up just because it isnt needed for 5 pounds. Try that, and if not then we'll go from there.

Casper

Um, your MAF is WAYYYY too close to that turbo...

mb1604

thats what i was thinking. ive never seen one like that lol

Jay-M

First question... do you have a wideband?

if you do, you'll know if you are running lean or too rich right before or as you "hit the wall"... it could be those two situations

double check your fmu... do what alex recommends.

with a MAF system, when you have the MAF sensor before the turbo, IT HAS TO BE RECIRCULATED!!!

recirculate it using that dsm bov or if you want the sound, you should look into investing into a DUAL CHAMABER BOV (one for the atmo, one for the recirc)

zoned019

MOVE THAT MAF! Your main problem is that after awhile your MAF gets WAYYY too hot and cannot correctly read airflow anymore .. move it as far as you can away from the turbo (12-15" at LEAST)


Also I would recirculate the BOV..dump it between the MAF and the the inlet (if you want the cool woosh do what jay suggets and get a dual chamber)

Jay-M

^^^

yes to that as well

Tibminn

well i tried what alex suggested. the "wall" for lack of anything better to call it was no longer there, BUT you could tell it was running super lean... if i accelerated slowly it pulled decent, but if i gave it any more than 3 pounds it would go slower than n/a. Ugh, I dont get it.

ok so lets assume the maf is getting hot and not reading correctly. that may conytribute to the problem, but the lack of 'wall' from not having the fmu makes me think this is an fmu related problem. and i guarentee it is hooked up correctly. now what!?