[tvsn94]

Ok , I have had this tune for a long time, lately it started going lean , per the WB, and it will not pull over 3.5 volts on the MAF. I use a Quarter horse. It does not detonate, just falls on its face and stutters . When this happens the Load max out (1.99) and the inj duty maxs out at 99%. Fuel press stays good and follows boost 1 to 1.
It seems like this started gradually but it to the point that any RPM over 4k is the problem zone. Startup, cruise and bottom end are as they always were.
I have swapped out or replaced,,MAF (HpxE) , PiP sensor., Alternator, TFI, Checked all grounds.
I have pulled data logs while alt is disconnected, with fan disconnected, with MSD disconnected . Always the same.
I have swapped to another ECU, as well as changed CAPs in one of them, No changes.
Surly one of you have seen this before, I am to the point that A Holley system is next.

[cgrey8]

The thing that's confusing is Inj Duty maxes at 99% and Load going to 1.99...yet you've confirmed fuel pressure is not being lost.

This makes me think the EEC is going off in the weeds and the values you are getting are screwed up and don't reflect reality. My initial suspicion would be it's a problem with a function. The first column of ALL functions must have the top and bottom cell represent the absolute max and min value...and all cells in the middle need to be a gradual transition from max to min. If you don't have this, then the EEC can go wandering off the reservation and the results are typically intermittent, with bad results, and thus never what you want.

With only this info, my first suspicion is a problem with the tune.

[tvsn94]

I would not disagree about the tune,.I have made that mistake .
What gets me is I made no changes in a very long time. Also I have dropped in many old tunes and it does the same thing,
also, I have done the Read Ford check and all is good. ?????

[cgrey8]

Putting in old, known good tunes that didn't display this behavior at all does kind of rule this out.

But right now, you have seemingly conflicting info. So try to confirm the data.

Get it back into this scenario and confirm that while you are supposedly at 99% duty cycle on the injectors, you also have the fuel pressure you expect. More importantly, you have to answer why the EEC "thinks" it is appropriate to command 99% during a condition that shouldn't be calling for that much...or confirm that the duty cycle value being reported is just bogus. Note Duty Cycle's calculation is a combination of Injector PW and RPM. So pay more attention to what the Injector PW and RPM are. From there, you can calculate your own Duty Cycle.

If you can, confirm that the MAF voltage is consistent with what's being datalogged. If the MAF really is reporting 3.4v under a hard WOT condition you would expect well above 4v for, then you may have some kind of mechanical issue. Either air is getting in unmetered (which would definitely cause a lean condition) OR something is choking off the airflow and preventing the expected amount of flow. But even if either of these happened, this wouldn't likely cause the datalogged values to go screwy.

So start confirming what you think you know as best you can.

[tvsn94]

I intend to follow up, I have been working on this for over a month. Your thoughts are well founded. I am completely befuddled at this point, ANY thought are welcome.
Years ago I had an 84 SVO, completely diff inj system (bosh I believe) it did something similar, as per driving problem, and I never tuned it, it was stock. I never found what it was but suspected noise from the Alt.
Still looking

[tvsn94]

by the way,,the old tunes react the same way. my bad if I misled you

[Paulie]

Can you post a datalog?

[EDS50]

I would be interested in the tps is functionality. Any abnormal behavior? I would verify with a dvm and performing a sweep test or just turning the key on and activate the datalogger and step on the gas pedal and make sure you have full function from closed throttle to wide open throttle. I would also look into replacing the QH battery and clear the ram from the QH under the hardware tab and reload your tune to see if it helps.

[tvsn94]

attached is a data log
this is my most recent, its a little diff from the older ones in that it does Not show 99% inj duty.
I will say that the onset is becoming sooner , and voltage is lower at onset. I just don't understand whats changed .
Map represents boost in this file.
the TP data logs with this

[tvsn94]

Oh one other thing, when things went south I was running a chip that I burned. I found years ago that the QH seemed to be finicky. Of course i am using the QH now to figure this out.
I really do appreciate yall's input.

[tvsn94]

Well in the for what its worth,,,I posted that Data log. It showed Inj duty( less than 99%), that was the first one that did. The car responded rather violently , some detonation, that was a first. any way, I studied it some and determined it was NOW pig rich in most of the UPPER rpm's. At first I thought it was a collapsed muffler, but ruled this out as it has started to respond to tuning. I have since leaned it out 12-20% in ranges 2.2vols up to 3.8 volts and it's coming round.
I still am confused but will take what I can get. I surly want your input as to what the Heck is going on.
I have a BUNCH of time and $$ in this and just can't sleep without knowing. THXS

[EDS50]

If you get a chance, upload your current tune so we can take a look at it.

[tvsn94]

u bet I will pull one tomorrow as I dial it in. Damnest thing is it got worse, dropped to 2.8 volts on Maf then showed a decent duty on the inj. my WB had been showing dead lean and no amount of fuel helped, it never detonated , I figured it was shutting fuel off.
I pulled that one data log and it now had inj duty. and load is back to something I understand. Started leaning it out and I am WAY less than the original tune,,But it's coming back.
I will gladly share this problem.
I have changed and rubbed on so many things I may have missed something, I am not to proud,,,,BUT I am confused.

[indy2000]

Your Maf only measures air mass entering the intake.

If your engine is hurt and cannot ingest more air, your maf is not the issue.

misfires, will cause all sorts of load spikes, and that data cannot be relied on.

I suggest you verify your base engine first.

[tvsn94]

No argument to your logic, I was thinking a broke valve spring But can find no evidence upon inspection.
Originally I thought the ignition, every piece of that has been changed, everything .
I am now focusing on voltage drop at high RPM's. Alt has been swapped,,No change . still looking and thinking.
It is showing promise, I have 90% tuned in now. still wonky at 3.5v maf and 5000RPM. tuner software is calulating 754Hp, then goes to heck.

[skunk]

Been awhile since ive posted. Hey y'all... hope everyone is doing ok these days.

How is your air filter/maf/turbo intake set up? Is it possible a hose is collapsing.The old SVOs had a habit of collapsing the intake hose between the turbo inlet and the air meter which would cause this kind of issue.... maybe you are having similar issues?

John

[tvsn94]

No hose between air filter and turbo inlet. I use a big 8X12" round dry flow pleated , mounted in the right fender. Gotta use a lift to get to it LOL
That old SVO would fall on its face and you could lift the throttle just a bit and it would pick back up then do it all over again, you could keep doing that to 7grand.
At one time I had bout every part for that thing piled up in the garage,,,,Maybe I should have kept them and sold on Ebay.

[indy2000]

No argument to your logic, I was thinking a broke valve spring But can find no evidence upon inspection.
Originally I thought the ignition, every piece of that has been changed, everything .
I am now focusing on voltage drop at high RPM's. Alt has been swapped,,No change . still looking and thinking.
It is showing promise, I have 90% tuned in now. still wonky at 3.5v maf and 5000RPM. tuner software is calulating 754Hp, then goes to heck.

look at the NB 02s when you go WOT, at warm idle, snap throttle to WOT, what is the voltage?

[tvsn94]

Ed here's that tune

[EDS50]

Ed here's that tune

I dont see it posted.

[tvsn94]

057-11-5 cold start.BEB

057-11-5 cold start.BEB

057-11-5 cold start.BEB

Hemmm

[tvsn94]

well looks like it finally went LOL

[EDS50]

well looks like it finally went LOL

I see them now...is there a way to post them as .bin? I dont think I can open .beb format.

[tvsn94]

Indy
O2 reads .873 at warm idle
drops to .220 when snapping to WOT

[motorhead1991]

Indy
O2 reads .873 at warm idle
drops to .220 when snapping to WOT

That tells me that your idle is rich and snapping the throttle swings way lean.

[indy2000]

Indy
O2 reads .873 at warm idle
drops to .220 when snapping to WOT

your idle needs to swing from 0-1volt many times a second, unless you are forced open loop

you have a fuel delivery problem.........

pump, reg, inj..........etc

[tvsn94]

Ed I have no idea how to convert the tune

Indy, you are correct, I am set up a bit rich at idle. It seems to like it. I can set it for any AFR/Lambda I desire. I am doing the tuning.

[indy2000]

Indy, you are correct, I am set up a bit richt the tune
at idle. It seems to like it. I can set it for any AFR/Lambda I desire. I am doing the tuning.

If you go lean on engine increased acceleration, you will misfire, it has to go rich

[tvsn94]

OK, first i want to thank all that have attempted to help with this problem.
After a LOT of hours and several buckets of $$, I found the problem. It appears that I had a new set of Mallory Pro ceramic end plug wires that broke down and allowed RF noise into the ECU somehow.
It would be criminal not to share this experience with the group. The final fix was a $50 set of Ford racing wires,,,and botabing, It straighten out.
Down side is that all this work and tune and replace and ECT. I now have a leaky head gasket.LOL