poormxdad

Long story, medium. I had a great weekend on Summit Point. I pushed the car pretty hard. I trailered her home and later drove it into the garage. No issues. Today, I pulled the car out of the garage and parked her on the street without issue. A few hours later I started her--I always wait until the MTX-L begins to read before I move her--no issues heading to the garage. However, when I stopped in the garage the MTX-L was reading AFR 9.9. It wasn't idling like she had a good tune and a bad sensor, she was idling like something was wrong. I decided to calibrate the sensor. After calibration, the same thing happened--she was idling at 9.9 AFR on the gauge, and it felt and smelled like she was really rich. I fanned the throttle several times and it all came back to normal.

I have four consecutive track days coming up in early November and I don't want to miss out on any track time. What might have caused the shenanigans?

Thanks,

deezums

iTrader: (3)

Does it seem to stall at such a lean reading, or is it jittering around 9.9 like you'd expect?

Were you up to temp when you got back to the garage? If so, if you disable EGO does it seem to idle better?

I hate hate innovate stuff, and that would be my fist guess as to what's wrong, if it seems to be stalling on readings.

SpartanSV

If it was running rough and showing stupid rich it may actually be that rich. Other sensors like MAP or temp could cause this.

A datalog of the issue would tell us so much more.

rwyatt365

I'm on the "I H8 Innovate" bandwagon too, but that won't solve your problem.

Could it be that, after running hard on the track and then trailering home, the O2 sensor or exhaust got "loaded up" with residual fuel that had to be blown out before things read properly? Can you take the car out on the road for some subdued driving and see if things stay "normal"?

Other than replacing your wideband conditioner, I've got nothing.

gooflophaze

Not on the h8 innovate bandwagon, but if the wb is reading rich, and it smells rich... its probably rich.

EGO shouldn't be kicking on till you're at temp. "Residual fuel" doesn't track - wideband is measuring oxygen, not fuel.

It's something else in your tune. Stop jumping to conclusions on the wideband. Start looking at your ASE and IAT, and of course, need a log.

poormxdad

Alrighty then... my current tune and a short log.

MLV shows she's idling at 68 kPa and at -4.6 pounds of boost. Fanning the throttle a few times didn't fix anything. Bad recirc valve? The car was running just fine a week ago, and no changes have been made to the tune.

Thanks much in advance,

gooflophaze

Don't see any fuel corrections in play, sensor inputs look alright - but will say 68kpa seems awful high for idle - I'd expect mid 40's. Maybe that's just my inexperience with rotrex, but I'd be checking for vacuum leaks in the MAP line. Log is too short to really see any real TPS -> MAP correlation to for sure call a leak.

poormxdad

She usually idles at about 32 kPa, which is why I have that row in the VE Table. EGO would not have come on--the coolant temp was too low. I didn't want to run her any longer than that.

There are no weird obstructions (like a blue paper towel) in the intake piping so far, and the throttle body seems to be working as advertised.

gooflophaze

32 sounds more right, but yeah, you need to check the vacuum line specifically - for either a kink, a hole, or a tee that's fallen off.

poormxdad

Recirc valve has a pinched, out-of-groove, O-ring, but I don't know how that could have happened in the last couple of days. I haven't effed with it.

codrus

So I'm by no means an expert, but here's where I'd start. I agree with gooflophaze that if it's running badly and it says it's rich, then it's probably rich. Misfire doesn't show rich, it shows lean (due to oxygen sensor, not fuel sensor), so it's not ignition that's the problem. The only way it's rich is if it's injecting too much fuel.

Do you have an idle log from before the problems started you can compare to? How high are the actual injector on-times compared to that? If they're larger then look at sensors/etc and figure out why the computer is commanding too much fuel.

If the on time is the same as before then you're getting more fuel than the ECU expects. How's the fuel pressure? Maybe a bad injector hanging open longer than it should?

--Ian

Edit: crazy other thought -- do you still have an EGR pipe and valve on the engine? If so then maybe that's leaking exhaust gas into the intake and taking away some of your oxygen?

Blkbrd69

MTX-L was reading AFR 9.9

Normally followed by E8 error code.

codrus

Poor idle vacuum could be a symptom of the car running badly if the ECU is opening up the IAC to compensate and keep it from stalling.

--Ian

poormxdad

I believe I need to get the car running with the intake plumbing sealed without the recirc valve in the system. Otherwise, the bad valve will be the wild card.

gooflophaze

for diag purposes, could just remove the intake tube. rotrex is gonna be pushing out air to .. whatever, throttle plate's gonna keep vacuum in the manifold.

but the basis of my diag is that you're seeing 68k at 1000 RPM which is by and large an untuneable area (imagine a turbo spooling and making boost at idle - just doesn't happen). Usually when I've seen a pinched/loose MAP line the car will barely run if at all. As you raise the RPM's with a throttle blip you're getting into a more reasonable x axis.

deezums

iTrader: (3)

I don't believe an engine can read an actual 68KPA while loaded with fuel without eventually revving to the moon. It also never fixed itself in that log, still rich and heavy load for no reason.

Map isn't reading right is my guess. You could unhook it at the source and try making some mouth vacuum on it, you should be able to get it to ~30KPA. I think it's reading ~2 times high, which means lots more fuel with no air to compensate.

You run speed density and I assume you just have it set up like a blowoff valve. The throttle still throttles, no matter what the bypass valve is doing. Doesn't explain the massive vac leak, nor why it doesn't rev with extra air.

The wideband signal isn't the choppy crap they eventually do when they fail...

poormxdad

Gents,

Short log with the intake tube disconnected from the throttle body, and the vacuum line to the recirc valve capped off. She seems to be idling normally. Unfortunately, the BOV (recirc valve) I'm using from Frozen Boost (Universal Type 10) is out of stock until well past when I need it.

Thanks much,

poormxdad

I pulled out the original recirc valve that came with the Kraftwerks kit from spare parts purgatory and hooked everything back up. It had the same super rich issue, which is why I replaced it way back when.

Question. When I plugged the vacuum line where it attached to the valve, the problem went away. Does that rule out any other vacuum issues and I can assume I just have another leaky recirc valve???

Thanks,

deezums

iTrader: (3)

If your idle load dropped to mid 30's KPA or better, then yes.

Does your MAP line to the megasquirt tee off the reference line to the valve? If so I would change it so they each directly use a nipple off the manifold. A leak in the valve would not cause the ECU to improperly read the MAP in that case, and the vac leak would likely be manageable till the valve completely falls apart.