Incorrect tuning?

[Lt.Dan]

Hey guys, im curious here with an injector/tuning problem.

So im in the process of doing a mild rebuild on my 7.3 right now, with the thread being here: http://powerstrokearmy.com/forums/showthread.php?t=69087. But before i had to do this rebuild, i had gotten custom tunes from a company with my PHP hydra chip. Now my truck is a 96 california truck (had the fuel pulse dampener, blue sticker on the valve cover, but no GP relay shunt for some reason).

Well when i got the custom tuning, i gave the tuner the box code for the computer that is in my truck (which is MIF6 PCM (DPC-202)). And he determined it being an AA code computer, and thus, he insisted the truck must have AA code injectors. So i trusted the professional, and we loaded AA tuning into the computer.

Now it ran good, nice and smooth, had plenty of power, except EGT's were out of control. I would peg the pyro to 1500* as fast as my foot would hit the floor. No boost leaks, no exhaust leaks, ICP pressure was steady at 2600psi in the stock tune. And would build 25psi of boost if pushed hard, maybe 26psi if it was cold enough...

Now after the motor went, i pulled the injectors only to see them being stamped AB on them...

My question is, could these actually be AA injectors, with an AB cap on them? (thus actually acting like AA injectors and nothing be wrong?)
Or would the truck even run correctly if i had AB injectors, with AA tuning?
What are your guys thoughts on this?

 

[rusty1161]

Any idea if the injectors are original and still AB's? The "AB" or "AA" identification was on the solenoid, correct? If the injectors have been rebuilt, the solenoids are not reliable way to identify split or single shot injectors.

Rusty

 

[cleatus12r]

MIF6 is a split-shot tuning-equipped PCM.

 

[Lt.Dan]

I have no idea if the injectors have been rebuild. But yes, the AB was stamped on the solenoid. But that, also that the computer is split-shot tuning-equipped pcm, it had the fuel pulse dampener, california sticker on the valve cover, etc.

It was owned by an asphalt company before me, they put 280,000 miles on it, so i have no idea if they have been rebuilt or if theyre even original.

 

[79jasper]

Whoever the company was you got the chip from, I wouldn't trust.
That's definitely a cali model pcm.
1996MIF6
6-90P-R11
DPC-202
F6TF-AXG
7.3L F-250/350 & E-350 DIESEL - AUTOMATIC
CAL
FA20R02

Now to answer rather that would cause what happened to your engine? I don't know.
Doesn't seem like it would run right though.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[Lt.Dan]

Dunno if i should post their name, but the name is in the first post of my rebuild thread...

Im going to try and hit up another tuner and see if they can help me out with my future tunes...

 

[79jasper]

I would say normally they're okay, maybe it was a new guy or something.

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[Lt.Dan]

He seemed like he knew what he was talking about, and at the time i was a little ignorant to the entire situation, so i just took his word for it, thinking to myself "trust the professionals"...

Last time ill do that i hope.

 

[Justin@DP-Tuner]

Running split shot (AB) tunes on single shots (AA) will cause it to have a real lopey idle. However, running single shot tunes on split shots normally runs okay (not the best, but nothing noticeably wrong). The problem is that AB codes are 130cc and AA codes are 90cc. The 130cc injectors should have more fuel pulled back in the tuning. That is likely why your EGT's were out of control.

 

[superpsd]

To verify if they AB split shot injectors. As you said you had the injectors out. Peer into the fuel delivery holes. There should be a hole on the side of the barrel and a spill port if they are splits. Splits are also commonly quieter than a single shot injector.

 

[Lt.Dan]

Running split shot (AB) tunes on single shots (AA) will cause it to have a real lopey idle. However, running single shot tunes on split shots normally runs okay (not the best, but nothing noticeably wrong). The problem is that AB codes are 130cc and AA codes are 90cc. The 130cc injectors should have more fuel pulled back in the tuning. That is likely why your EGT's were out of control.

Thats exactly what i thought, it didnt run "perfect" or "smooth", but it definitely didnt seem like anything was wrong. And the guy doing the tuning even told me he pulled back the fuel after i was complaining to him that i was having high EGT problems. After he did that, it made it a little better, but it was still super high, he blamed it on being a mechanical problem, not a tuning issue.

To verify if they AB split shot injectors. As you said you had the injectors out. Peer into the fuel delivery holes. There should be a hole on the side of the barrel and a spill port if they are splits. Splits are also commonly quieter than a single shot injector.

Good idea, only issue is i already gave them to my buddy to have tested. Im sure they will be able to tell me if they are splits or singles. Thank you though.

 

[Luke@MillerPerformance]

If you have stock injectors, why did you buy custom tunes? The ones from PHP pretty much max out what the stock AB codes can do.

 

[Lt.Dan]

It wasnt about trying to get more power out of it, it was just that PHP had very few tunes for my ECM, so i went to another company to get a bigger variety.

 

[Luke@MillerPerformance]

It wasnt about trying to get more power out of it, it was just that PHP had very few tunes for my ECM, so i went to another company to get a bigger variety.

You checked under VCAB0_02 for files as well? I don't have my calibration list in front of me but that one should have pretty much every tune possible for a CA emissions 96/97.

Just as note, if you guys encounter a strategy with minimal files available, either there's a preferred based calibration to be used (like in the case) or the files just need to be added to the server.

 

[cleatus12r]

You checked under VCAB0_02 for files as well? I don't have my calibration list in front of me but that one should have pretty much every tune possible for a CA emissions 96/97.

VCAB0_02 IS NOT a split-shot calibration.

 

[old man dave]

Whoever the company was you got the chip from, I wouldn't trust.
That's definitely a cali model pcm.
1996MIF6
6-90P-R11
DPC-202
F6TF-AXG
7.3L F-250/350 & E-350 DIESEL - AUTOMATIC
CAL
FA20R02

Now to answer rather that would cause what happened to your engine? I don't know.
Doesn't seem like it would run right though.

Sent from my SAMSUNG-SM-G935A using Tapatalk

1996 auto trucks use a split shot calibration DPC-202 and AB injectors. Since its a DPC-202, there is no provision in the PCM for glow plug current monitoring like the 1997 DPC-312/311 California has. So, no factory installed current shunt and no associated wiring in the harness. The 1996 California PCM plug pinout is the same as the Federal PCMs unlike the 1997 California PCMs which have exclusive PCM pinouts and different wiring harnesses.

My buddy has a 1996 California MIF-x truck and it does not have glow plug current monitoring. As a comparision, I have a 1997 California and was very surprised to find that the 1996 didn't have the current monitoring feature. I think the DPC-202 PCMs are early model 1996 California trucks, later in the model year the factory switched to the DPC-311/312 PCMs. Otherwise, the early 1996 has the rest of the California truck features.

 

[Lt.Dan]

That explains more of it, all of the research i did back when i was converting to efuel, didnt explain what you just did. It seems there is getting less and less information on these OBS trucks as time goes on...

 

[old man dave]

The good news is if you ever install single shot injectors and your super rare 1996 California DPC-202 PCM goes bad, just get a easy to find Federal DPC-202. The PCM plugs and harnesses are the same for the early 1996 Californias and the Federals.

Don'r know if the tuners tune for splitshots using a Federal PCM. They do for using singleshots with a California PCM.

If you have a bad California DPC-311/312, then you either have to locate a replacement California (very rare) or repin the PCM plug for the Federal PCM plug pinout and use the Federal PCM. The DPC-312 trucks use completely different engine harnesses than the Federals.

There are other differences but that's a different discussion. You can PM me if you want.

 

[Justin@DP-Tuner]

The good news is if you ever install single shot injectors and your super rare 1996 California DPC-202 PCM goes bad, just get a easy to find Federal DPC-202. The PCM plugs and harnesses are the same for the early 1996 Californias and the Federals.

Don'r know if the tuners tune for splitshots using a Federal PCM. They do for using singleshots with a California PCM.

If you have a bad California DPC-311/312, then you either have to locate a replacement California (very rare) or repin the PCM plug for the Federal PCM plug pinout and use the Federal PCM. The DPC-312 trucks use completely different engine harnesses than the Federals.

There are other differences but that's a different discussion. You can PM me if you want.

We have done this many times. It is really the only option for 1997 Cali guys who cannot afford to get different injectors.

 

[Lt.Dan]

I guess i kind of lucked out with the early 96 california PCM then haha, good news!