HALP! Lost Fuel while Drivng to Work

DrFishbone

SCCoA Member
Well, I'm back again - this time looking for some troubleshooting help. Car died on the way to work this morning and I'm trying to troubleshoot from the office. :rolleyes:

I just so happened to be datalogging too - log attached.

At the end of the log, you can see the STFT/LAMBSE go wacky...if I have this straight, negative STFT pulls fuel, so why is the car pulling fuel when the AFR's are so lean (lots of O2 picked up - almost atmosphere). The log shows it's intermittent, but after I shut the log down, it stayed running for several minutes as I maneuvered the car to a safe parking spot (all the while running around 22 AFR). Turned the car off and restarted, problem was still there...would just barely idle, but AFR was around 22...after a few seconds of idling, it perked up and ran normal for about 20 seconds, then back to the 22AFR.

Any ideas? I have a couple, but I don't like them. Tach signal was never erratic.

Hoping to get some ideas to check while I'm on break and get it fixed without having to tow. :D
 

Attachments

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Pulled the codes...... :(

15 - *gulp*

67 - who cares...

78 - *gulp*

PCM fault / failure codes. Car started up and ran poorly, then normally.

I suppose i should first check the EEC connection and QH connection before drawing any conclusions, but I did find (while looking at the tune yesterday) that I had left the ZKAMCLR switch on "reset" for an extended period of time in BE.....I wonder if that screwed up some of the circuits within the EEC...I had switched it back to "normal" yesterday and have driven it 30-40 minutes since then.

Anybody else have these codes that led to a different diagnosis?
 
Swapped out the PCM / EEC yesterday (thanks Jeff!) - but still acted silly. I have a couple of other ideas, but I'm wondering if the quarterhorse might be at fault...

Any other ideas? Those codes only showed up briefly yesterday. Haven't gotten any new codes since then, even though it still has the intermittent problems like above.

I might be over thinking this...without the quarterhorse and AFR gauge, I would have thought it was the dis......hmmmm.....even though there are no indications on the tachometer that it is faulting.
 
There have been reports of people loosing there tunes on the early version of QH could it have reverted back to the stock tune when this happened?
 
There have been reports of people loosing there tunes on the early version of QH could it have reverted back to the stock tune when this happened?

I don't think so...fan settings stayed the same.

I tried rewriting the tune to all "slots" too..no difference.


:/
 
Matt,

Had something very similar happen to my daughter's Ford Explorer several years ago. In her case it ended up being one of her o2 sensor wires melting and shorting out on the exhaust manifold, which caused the EEC to go into "limp home mode". Don't know if the SC's EEC even has that feature.

David
 
Ive melted 6 or 8 o2s over the past couple years:rolleyes: No codes, or limp mode, but the car sure as hell ran like poo lol. Its interesting being in rush hour 70mph traffic trying to get the lap top out and open to force the car to run in open loop:eek: Its worth inspecting in your case if everything else seems mechanically sound.
 
Will do, gents....

I bet it's not a coincidence that I was fiddling with the wbo2 the night before the problems happened. I thought I would pull the narrow band while I was at it, but changed my mind when the connector didn't want to unplug and wifey started griping about me being in the garage. :rolleyes:

Maybe I got it loosened without knowing it, or even plopped it against the exhaust.

Thanks
 
Thinking back to last night...bank 1 lambse seemed to float around and differ significantly from bank 2 and the wbo2 readings....even though the wbo2 reads off bank 1 on my car.

I think you guys figured it out...and once again I overthink things and expect the worst.

I let you know.

:)
 
O2 sensor looked ok...unplugged/replugged anyway.

But...

Started it up and let it idle for awhile and the problem returned.

I listened to it for a minute and thought I'd check for spark...found that while it was running bad (sounded like cyclinders were missing everytime), #1 & #5 were not getting spark. These two share a common coil I think (left-most). I'm thinking it almost has to be the coil pack or DIS. Getting ready to test the coil pack - looks like it'll be fixed shortly though. :cool:
 
I wonder if i was running on two cylinders the other day....there are definitely two "staqes" of the symptoms. First stage is it runs bad, but keep sidle pretty well and doesn;t sound too bad. Stage two is it barely runs at all, but still runs.

If I was running on two cylinders (if that's even possible), that would mean that two coils in the coil pack were bad (sounds unlikely)..or the DIS is flaking out. Well, anyway, we'll find out. I decided to swap out the coil pack first...so we'll see.
 
Swapped coilpack - same two cylinders weren't firing.

Swapped DIS - running fine so far.

Add that to yet another group of DIS module failure symptoms!!
 
How has the wiring looked during those swaps? Oil soaked? Corroded terminals/connectors?
 
How has the wiring looked during those swaps? Oil soaked? Corroded terminals/connectors?

Clean clean clean

Module itself for sure.

Swapped a bad spare into though. This module just twitches the tachometer every 15 minutes or so...May or May not miss while twitching.

Might as well go through my stash and mark the bad ones! :)
 
Is there still a new source for DIS? I remember when mine went bad. Would like to keep a spare in the trunk I figure.
 
Is there still a new source for DIS? I remember when mine went bad. Would like to keep a spare in the trunk I figure.

'Standard' brand, I think - RockAuto, AutoZone, etc. But if I was to bother carrying a spare, it would be used, so that any warranty doesn't expire sitting in the trunk. Just run the used until you can buy new, then enjoy. I'm sure someone here can provide a used one.
 
I bought a new one from Advance Auto several years ago - Autozone also carries it.

Limited lifetime warranties too...this will be the second time I've used the warranty. :)
 
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