legacycentral bbs

So the wagon is running worse and worse. I thought I had cleared the ECU finally, but it still runs like comeplete horse crap. Jerking and bucking when off boost, and now, when on boost it jerks and bucks. Its still plenty powerful on boost, but only when not bogging down. BLAH!

I pulled spark plug #2 (because it is the only one I can do by feel in the dark) and checked it out inside and I was hoping to see that it was black as hades meaning I just needed to replace the plugs. Nope, perfect looking, with no detonation damage or signs of richness.

When I actually blew the top off of #4 piston, the car didnt run like this, it just ran on three cylinders, so it doesnt seem like I broke a piston. And since the symtoms just get progressivly worse while off boost, it doesnt seem like boost is the issue.

So it comes down to the 370cc injectors and my ECU. I think. Ahgg....... It ran so perfect for almost 40 days, then one morning started with the hurky jerky.

Maybe I am not truly resetting the ECU. Or does the ECU learn faster and faster everytime it is reset?

Sounds like it's not mapping A/F properly. . . and is messing up hardcore when in vacuum.

If the injectors were the culprits, I don't think it'd run smoothly ON boost, either.

Vacumn, I need to check some lines.....

Another thought is that it could be bad gas, or a clogged fuel filter.

Damn, now that I have no time or money, I need to replace the plugs, wires, and fuel filter and hope for the best. I'll do a compression test then as well. We shall see and for now, the SC is staying in the off position.

Damn Doug, the day you get that thing running consistantlly, we need to throw you a party.

Yeah, and I hope the party is at the dyno.

Now I am suspecting that once my oxygen sensor warms up, then the ECU is reading it and freaking out. I am going to try unplugging it and seeing if that makes a difference.

MAF clean?

MAF unhooked. Or at least some wires were crossed I think. The car ran find and dandy all day but only after I unplugged and replugged the MAF sensor plug back in. I cut these lines once and put them back together so I think I just had a bad connnection. We shall see this weekend.

Do you happen to Vikash's ECU scan prog? If you did you could check the O2 sensor voltage. I'm sure you could check it some other way though. Could the knock sensor be to blame?

I think it was the MAF lines. Ran last night and all day today and not a bump, jerk or waffle to be had. Just pure subaru power scaring all the 5.0s out there. I watched them just cower and scamper away when the wagon filled with a dad and kids would pull up at the stop light!

What psi are you pushing, Doug?

7 ish. sometimes 9 with a new belt.

Oh, I just noticed your sig. Was it always like that?

No, but it was changed about 1 day before you asked.

wagon is running fine. I am about 99% convinced I just had the MAF wires goofy. Thank God.

You should consider running a turbo ECU and converting adding the sensors and stuff. That might be better at handling boost timing and such.

Hey Doug. You ever look into Megasquirt?

http://www.megasquirt.info/

I have "looked" at it, but that is it. But as it is, the wagon is running pretty awesome and I am now getting about 18 mpg around town, not too bad. And it is fast enough to get in trouble. So I am going to leave the engine crap where it is standing and focus on two new front struts and brakes for now.