sr20 running rich, misfiring, flooding, black smoke

[boost86]

So I've tried to troubleshoot this problem myself for the past one and a half months..

My car has an s13 sr20det blacktop. It's running a GT28r tuned on a PowerFC with 440cc injectors. Before the car started running bad, the car was flawless. It has an aftermarket FPR by the way.

Anyways, one day it started running horrible. Like the flick of a switch, it ran bad. Sitting at idle it misfires horribly and blows black smoke because it's running insanely rich. If I try to get into boost, it won't go very fast and will stutter and backfire and leave a giant black smoke trail- similar to a diesel truck. Oh yeah, it will rev all the way to redline but it doesn't do it cleanly.

The car will eventually flood itself out and I'll have to air off the top of the pistons for a day. After that it runs a lot better until it floods again. Plugs are black and soaked in gas. If you rev the car, the idle will drop and start bouncing up and down until it kills itself from being rich.


I've replaced my CTS, fixed all the boost leaks, fixed vacuum leaks, checked TPS voltage, swapped a good MAF in, put in new wiring to the MAF, replaced the injector o-rings, checked the FPR and checked the injectors for leaks. If I put in the stock E5 ecu, it will run a little better at idle and not kill itself but its still doing the same thing. Although the E5 ecu wasn't meant to run the 440cc injectors, it runs better than the PowerFC.


Any suggestions? Knock sensor? PowerFC tune wiped off? Wiring harness?

[army240]

You can easily check the injector correction in the powerFC... If they are a 100%, either that parameter was erase or all your parameter were reset!

Frank

[boost86]

Thanks for the reply Frank. I don't have a commander so I'll need to borrow one. But I never thought about using one. I'm still wondering if it could be anything else but I'm leaning towards it being a problem with the tune at this point.

[Jybfan04]

I'm having a similar issue, albeit not having a power fc but rom tune. How did you check your FPR to ensure it is working properly?

[EvoVIII808]

Yeah check you fuel setting on the PFC. IF you can try to clear it, re-install the setting and do the initial Learning on it.

[boost86]

Jybfan04-
I tested my FPR using the fuel pressure gauge that is attached to it. The gauge reads correctly and the pressure shoots up if I squeeze the return line. In addition, I also took it apart and looked over the internal components and everything appeared to be in order.

EvoVIII808-
My only worry at this point is I've NEVER heard of anybody else's PowerFC getting their tune wiped off. Although when it started running bad, the PowerFC unit was flopping around on my floor when it usually is in the kick panel. So that was suspicious.


Something else I didn't add: While running, if I pull the fuel pump fuse, the car seems to idle PERFECTLY. No misfiring or anything. And it quite a few minutes to stop running.

[titangts]

yeah sounds like the PFC is giving you the issue.. check your settings to make sure they are good.. also if you havn't changed your oil DO IT NOW.. fuel breaks down the lubrication properties of the oil and in terms washes down the cylinder walls and inhibits scaring.

if you think the settings have changed..give steve shadows a call (or email) and for $80 bucks he can give you an AWESOME base map.. hope you figure it out homie


EDIT:::: i did have this issue...and it was my fuel pump on my 2jz set up..i had 5psi..but you said your pressure is fine..

[NAVY-ET]

I had a lot of these same probs
And it was that I had loose grounds on the back of the intake just might want to check. There is 2 10mm bolts back there
Sent from my Desire HD using Tapatalk

[boost86]

Thanks for the suggestion Navy,
But they're both tight.

titangts-
You're totally right, there is fuel in the oil. That's why I've got a fresh change of Mobil1 waiting :D
I think I'll call Steve, but it's difficult for me considering I don't have a commander for my PFC. Sounds like I might have to buy one!!

This all seemed like it was a fuel pressure issue or an injector o-ring issue, but it certainly isn't! Which is confusing as fvck.

[EvoVIII808]

Yeah, My PFC has never erased the tuned. even after sitting for 8 months with no battery installed on my evo. Could possibly be the fuelpump, next thing i would think, would be the fuel pump. But you said it was good.

[boost86]

Yeah, My PFC has never erased the tuned. even after sitting for 8 months with no battery installed on my evo. Could possibly be the fuelpump, next thing i would think, would be the fuel pump. But you said it was good.

I didn't think it was the fuel pump because the car is running insanely rich, not lean. If it was, I imagine it would start to get weak and flow less and create a lean condition. In addition, if I put in a stock ecu, it makes a huge change. So I'm not leaning towards a fuel pump at this point.

[EvoVIII808]

Yeah, i hear ya on that. What about Ignition? all Ignition Coils good?

[89hatchman]

bumping an old thread. This is the exact problem I had. Don't leave me hanging. WHAT WAS IT!!!?!?

[burgessn]

Sry to bump an old thread but im having very similar issue! Just got my car started after rebuild and it is dumping black smoke and idleing very rough. I checked all the boost lines. Unpluged each coilpack and injectir one at a time and idle dips so those are good! Any help would be great!
What should fuel pressure be?
When you unplug the maf the car shkuld die right? Mine doesnt should i start there??

[boost86]

Sorry I got back to you guys so late. I replaced my Power FC with another Power FC and it voila it was fixed! The problem was that the injector drivers in the ecu were bad and the injectors were unable to be controlled! A new ecu remedied the situation! If you guys haven't tried swapping your ecu with somebody else's, give it a try! Not saying it will fix your issues, but the thing that usually fries them is a faulty wiring harness at the injectors. Hope this helps.