Blow through MAF issues

[rjyentsch21]

So after I rebuilt the engine I had the motor set up with the MAF (stock) on a pull through setup. I got it to idle, but it was rough and would ?miss? a bit more than it should. When trying to rev the engine or drive it, it would be very rough from about idle to around 2000 rpm, then it would smooth out. Coming off the throttle would also cause it to try to stall. These symptoms seemed to point to either a problem with the BOV (which I did have recirculating) and/or the MAF being in pull through. So yesterday I reconfigured everything so that I now have a blow through MAF on the cold side and an open BOV in the hot side IC piping...except for one problem: I can't get the dang thing to start now.

She'll turn over fine and occasionally cough like she's trying, but overall she is pretty quiet and just won't catch. Pulling the plugs I find that they are wet, but not fouled. I didn't mess with anything else (except for plugging one manifold vacuum that I had forgot during the engine rebuild and left open).

Obviously I seem to have created issues with the MAF. It tried to put it with about six inches of relatively strait pipe before the sensor itself, and yes, it is pointed in the right direction. Does the ECU even reference the MAF when trying to start? Should I try starting with the MAF unplugged? Is the tune for a pull through MAF SIGNIFICANTLY different from the tune for a blow through MAF? Also, is there any initial adjustment for the idle screw that I could have messed up when I plugged that leak? Would that make a difference when starting?

Full stats below, pictures can be taken if necessary.

Rebuilt engine w/ 8.5:1 compression, forged rods, new gaskets, bearings, all clearances checked, etc. etc. Compression is where it should be on an unbroken in engine.Enthalpy tuned ECU (16 bit daughter board)50 lb. fuel injectors255 lph fuel pumpadjustable FPR (currently set to the stock ~43 psi)tubular manifoldT3/T04E turbocharger2.5" open downpipenarrowband O2 sensor and gaugeboost gaugeoil pressure guageaftermarket temp gaugeblow through stock MAF on the cold sideBlow off valve on the hot side (open)wastegaterelocated batterynew clutchone stage colder than stock plugs gapped to .035MSD coiland nothing else that I can really think off being important right now...

[scheffler]

It started before you did tha swap and then sawped the MAF and fixed the vac and now it wont start? well it sounds like you over looked something (probly something stupid) i would go back and check eveything again and see if you over looked anything. I just did this 2 nights ago and it started right up, we basicly have the same setup, i am using the z32 maf but... i dont know did you diconect your bat and your ecu?

so it ran and ideled poorly with the vac leak? did you cut any of the maf wires when swaping? if you did did you hook it up corectly? dont think that would matter for start up any way dont think that the maf gets referenced at start up but i will still ask.

[rjyentsch21]

I did the engine rebuild and the turbo installation with the pull through and a very minor vacuum leak and it would start and idle, albeit roughly.

I changed to blow through and fixed the vacuum leak, and now it will not start. These are the only changes I made between running and now not running.

I did to the pigtail cut and extend on the MAF, but that was before the rebuild, so it can't be that. Maybe I pulled a wire splice loose when I moved the bundle over to the other side of the harness, but that seems unlikely...I'll check it just to make sure though.

I have disconnected my battery since moving the MAF to charge it, so that should clear up any temporary freakiness in the electrical system, shouldn't it? Is the some sort of "reset" procedure (like in my Paseo or my mother's Alero) that I don't know about?

I'm headed back to college for the week , so I'll probably have to let the 240 just sit and think about what a naughty girl it has been until I get back...It isn't my primary transportation (unfortunately or fortunately, I'm not sure which ) so I can afford to take my time to figure this thing out.

[scheffler]

if you want to reset your ecu disconect the battery and then turn all you lights on any thing that you can turn on push on the horn. this will drain all the power left in your car. turn everything that you tunred on off and reconect your battery. now you have reset your ecu. and it will take it a min once started to smooth out..

Other than that not to sure what your issue could bebased on what you have decribed. Check your ingnition ciol wier going to the disbutor if that is lose maybe you do have gas in you car right? i now it is stupid but hey. All your ground wires conected all your sensors and pluged in?

[WDRacing]

Let me ask you a question, how does a bad idle and poor running lead you to think the MAF should be placed in a push through setup? Since it's pull through from the factory.

The problem is very clear. It's not the MAF, cause the car will start with the MAF disconnected, it just won't rev past 2500. Try disconnecting the MAF, if it starts then you either wired it wrong or did something else in the process.

The main point is this. Before you change or modify anything, you need to have the car running in good condition or you're only compounding the issues. Moving the MAF made your earlier problems worse. So your best bet would be to move the MAF back, and get things working as they should be.

THEN try moving the MAF if you still want to.

WD

[rjyentsch21]

The car would idle and drive, but the characteristics of trying to stall after letting off the throttle, unwillingness to rev quickly through the low RPM's, and backfire and sputter comming off the throttle fit characteristics listed under either an atmospheric BOV (which wasn't the issue since mine was recirculated) or lag due to a pull through MAF, which sounded much more plausable.

I will try to start with the MAF unplugged to see what happens when I get back home.

[WDRacing]

What do you mean by lag? There should be no "lag" in the maf signal.