Calling All SR20 Guru's.

[justanotherbluesbrother]

So my SR20 Blacktop ran beautifully a week ago, although it had a boost leak limiting me to boosting 10lbs but thats beside the point. Still ran beautifully, never had an issue.

Then I decided to "fix it", had some down time from work, yes, lets do it.

So I changed some couplers and simplified my intake piping to the turbo, ran my PCV hose to a catch can instead of the intake to get rid of some nasty blow by, and changed over some vacuum hoses that ran to my boost controller (EBC).

I tried cranking the car today, and it starts, and then falls flat on its face. Giving it gas does nothing, it starts, hits 1000rpm if I'm lucky and instantly dies.
I have fuel pressure as indicated by my FPR gauge, the fuel pump is running (can hear it humming in the background) I have spark (it obviously starts and cranks) but it just won't hold idle.

I run an Apexi PFC, could it be an issue with the ECU?

I also run a Z32 MAF, and I tried unplugging it and seeing if it would idle rough or go into limp mode, and the same thing happens, Instantly dies, so its not an air issue to my knowledge.

I checked grounds, they all clear.

I tried searching the forums and all it brings up is IACV (the car literally ran a 6 days ago without issue) ECU or MAF. I'm just mind boggled. And of course this happens a week before a big car show so time is of the essence.

Anyone else have some opinions/idea's?

Any help is greatly appreciated!

[jr_ss]

Reverse your PCV system and see what happens.

[kruked]

Retrace everything that you touched. It ran before you tinkered w/ stuff, so, figure out what all you touched and touch it again.

[zombiewolf513]

Did you leave the intake manifold port for the PCV line open? That'd do it.

I would look at pictures of how the PCV routes undo that work you did.

[KoukiMonsta]

Why does everyone insist on ruining a perfectly good and we'll engineered PCV system? I just don't understand..

In other news, you caused this issue. Start reverting back to previous known working condition.

[ultimateirving]

Definitely sounds vacuum leak related. There is a catch can mod thread floating around with plenty of info on how to properly route a catch can and evacuate th crankcase properly. And you can do a boost leak test to find out where it's leak from. Start from the turbo Hotside back.

[TheRealSy90]

You should not be running the pcv to a catch can instead of the intake manifold.

[blkvrtswp]

Fuel lines swapped?

[justanotherbluesbrother]

I tried reversing what I've done and it still didn't fix the issue.

I blocked off the port on the intake manifold so there shouldn't be a leak there.

Whats the issue with running the pcv elsewhere? I've seen a lot of healthy setups where its ran to a catch can with no issues, but I'll do some more digging into properly routed pcv options but I'm not sure that would be the entire issue.

A part of me is thinking it may be IACV related, because it draws air from before the tb to operate idle, and the car simply won't, just not sure how it could just up and malfunction though when the car ran, was parked for 6 days, and boom nothing.

Appreciate the help and I'll be sure to let you guys know when I figure it out!

Until then, any other ideas are greatly appreciated

[Dboyizmlg]

Simplify intake piping to the turbo...?

Did you shorten the pipe? If the MAF is shortened distance to the turbo then that could certainly be the issue.

Try to keep the MAF as far away as possible from the turbo.

[TheRealSy90]

Originally Posted by justanotherbluesbrother

Whats the issue with running the pcv elsewhere?

Because you want a vacuum source to the valve cover/crankcase when at idle and off-boost driving, that's done through the pcv to the intake manifold because that's the greatest source of vacuum. When in boost, your pcv closes and your vacuum source is then through the other side of the valve cover via the hose to the turbo intake piping.

[justanotherbluesbrother]

okay so I've basically reversed everything to how it was and nothing. same poop.

Gonna rip out the IACV tomorrow or later tonight, hopefully a good cleaning will fix the issue?

Looks like I won't be making either show this weekend. bollocks.

[zombiewolf513]

Id be prepared to replace the gasket too

[justanotherbluesbrother]

SOLVED!!

Randomly today, before I decided to pull the IACV, wanted to make sure everything else checked out. Checked fuses, all good. Everything was put back how it was....

or so I thought.

Totally forgot I had this random bracket holding my maf+intake system to my wheel well so it doesn't jump around and everything while driving.
could it be that simple? that ridiculous?

Couldn't find it, so I put an alligator clip from one of the 4 nuts from the MAF to the filter, and then to the top of my strut tower (basically grounding it)

Started and ran beautifully like nothing had changed. Idled was perfect. success!!

So apparently, the ground in the MAF failed(?) and it needs this bracket to ground to the chassis or else it won't idle for some reason, not too sure where its lost there, but i assume it basically thinks the MAF is malfunctioning. I'm not gonna think too much about it, just gonna concentrate on getting the next bit of work done while the car can actually move haha

Fabbed up a new bracket, bolted it down, no issues.

Easily the most ridiculous thing I have ever experienced with this car. So random.

Thanks everyone for the advice!

[kruked]

The ground wire in your harness is probably no good.

Good to know that you solved your problem.