Injector Issue - Help Needed

Well, I called and checked in and they said it's running. It turns out they got the parts I told them to order in early today and, understanding that I was in a hurry, just went ahead and started the work in the order we talked about earlier (which is on me: I never got the chance to update them and give them the writeup Mike made above, though you can be sure I saved it for the future).

They changed out the IAC and it didn't help, then the fuel pressure regulator, and that didn't help. So they swapped the computer, and now it starts. The guy did say though that it wants to die if you take the foot off the gas: he suspects this is because as a new computer, it needs more calibration data still. He drove it around the block, and has it idling at the moment. While he didn't rule out that there might be something else wrong, it does run now whereas it didn't even start before.

I'll be heading down tomorrow to pick it up. I'll probably take it to a local guy that I trust who has more experience with older cars here, but hopefully it makes it home without an issue first.
 
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I finally got the car back after a bit of an odyssey and thought I'd post an update. It turns out it was a mishmash of things. Let's see:

Mass air flow sensor was no longer returning info (may or may not have actually been broken besides that)
Canister purge solenoid failed

And the big one:
Refurbished ECM that was added to fix the problems of the first ECM was itself broken (in a different way), requiring a third ECM

Seems to be running now, though. Took a fair while to diagnose in stages, then wait for parts at each stage.
 
KevinVarnes said:
So what all parts did you end up replacing? MAF, ECU (twice), and IAC, and fuel pressure regulator?
Click to expand...

Yeah, and the purge valve. Plus the second ECM had the car running so rich that I had to change the oxygen sensors, and I pushed up the plug change (they were already getting old) to now because they were now utterly encased in soot.

The fuel pressure regulator was the one part that actually didn't need to be changed, but a new Motorcraft one after 200K isn't hurting anything.

The mechanic also gave me some interesting context on why the guys in the small town that looked at it initially might have had so much trouble. He described a 97 as a weird sort of pseudo-modern car, where it's old enough that newer mechanics don't have much familiarity with them any longer, but not so old that anyone sees them as classics, and it's OBDII but right at the start so it's an early form that offers limited information compared to modern vehicles and their host of sensor data. I thought it was a neat perspective, though I'm not sure how others feel about that.
 
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I've messed with some newer cars that have additional monitoring PIDs, though they all seem like "bonus" data to me because I'm so intimately acquainted with my MN12s.

One weird observation I had was when I was logging data on our old 07 Fusion (for my dad, whom I gave it to after we got the Energi) to troubleshoot an oddity, is that it would not start if a live data session was in progress. I had to stop logging before it would start. :zdunno:
 
I don't know. I think the early OBD-II cars give plenty of diagnostic data. Maybe the Mode 6 data isn't as great? I don't know, I've never had to dig that far into it on an "old" OBD-II car. Roll up to their shop in an OBD-I car and their heads would probably explode. I remember thinking how awesome it was that you could even retrieve trouble codes to give you an idea of where a problem was. Now we expect/hope to completely diagnose a car through a little electrical plug.
 
The wonderful thing is that mn12's all fail the same way, Allowing trends and common problems to be figured out; making communities like ours invaluable.
That also makes vultures like verticalscope so terrible.
 
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