[Hybrid]

I've got a 99 superduty manual transmission with the DAC3 PCM code, and for the last couple of weeks the passenger's side of the engine refuses to actually run. It's been a sporatic "miss" off and on for over 2 years now, just finally got bad enough to park the truck.

Passes the buzz test fine (sometimes), all the wires in the entire truck Ohm out perfect including the injectors. The injectors themselves have been personally flow matched and they all are within 1cc of each other at any pw or ICP you want to run them at.

Every time on the cylinder contribution the truck fails on 1,3,5,7 non-stop. And completely unplugging the passenger's side only makes the most miniscule change in the way the engine runs. The spouts are actually pumping oil when those injectors are plugged in and the truck's "running", but I can place my hand, arm, face, whatever on the exhaust manifold at any time and it's ambient temperature.

I've run compression testing and all is well.

It's now got a new engine harness, new UVC harnesses, brand new injectors and a brand new IDM with no change.

I've got a manual gauge on that head and ICP is fine. I disconnected the fuel lines and fuel was flowing fine from supply and out of the return. The truck holds 68psi of fuel pressure and always has no matter what.

The buzz test sometimes throws the code p1293 high side open bank 1, and IDM failure, but this is the 4th IDM /ubbthreads/images/graemlins/frown.gif .

At one point I put a new IDM in the truck and it actually fired right up and ran like glass for about 15min before dropping the passenger's side again and limping back home on 4 cylinders.

Does anyone have anything? I'm almost to the point where I've got to cut my losses and get a new truck /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/frown.gif .

Thanks.

 

[trucktech]

Check the pin connectors at the harness on the IDM. It should be pin #24 and pin #12 on the 42 pin connector beside the fuse box in the engine compartment. If those connections look good, I would check the oil pressure in the right head, there could be a blockage or colapsed hose causing the oil pressure to drop off. Check the fuel pressure in the right head as well, low fuel pressure to the one head could be a likely cause.

 

[Hybrid]

Everything you mentioned has already checked out.

I've got 68lbs of fuel pressure, and whatever ICP I want (manual gauge in the head).

I've run the multimeter for continuity all the way from the IDM connector to the injectors themselves from low to high on that whole side, the other side, and everything else. I've also gone so far as to put 120 volts on the high side to see if the higher voltage was causing the current to "jump" over through possible insulation problems.......but still checked out on all wires and connectors.

I don't know what to do.

Thanks

 

[Vengeance]

Try it with a different pcm if you haven't already, and no chip.

 

[Hybrid]

PCM is the one thing I have not tried yet......... but wouldn't a bad PCM send an incorrect signal to all injectors? It doesn't send a signal for each injection event, basically just the fuel delivery command. Since 1,3,5 and 7 are all intermixed within the firing order, would it not be highly improbable that the PCM would do that to only the pass side cylinders?

Regardless, I'm going to go attempt to crank it with no chip (single shots on DAC3 PCM /ubbthreads/images/graemlins/crazy.gif)

I might throw the AWA3 in and try it.

Thanks

 

[JimTJr]

How about the IDM????? Does it send separate signals at least to each bank?

 

[trucktech]

I doubt that the PCM would cause it as well, the pcm does control the firing of the injectors, but it does it through the IDM and only through the low side. The high side from the IDM is common to all four injectors on each bank and normally a faulty IDM or a ground in the high side to that bank will shut the entire bank down.
With oil spilling from each injector, it sounds like each one is working but not putting fuel in to the cylinder.
Keep us informed as to what you find, this sounds like a very unusual one.

 

[Vengeance]

Since you have tried everything else, why not try the pcm? They have made some strange things happen when bad.

Try it with a different pcm with no chip in it, I realize the idle will be crap because of the single shots, but if you bring it up to around 1k rpm it will smooth out. Its worth a shot.

 

[Mach1]

Check the ground wire for that bank, look it over very good, make sure that ground is top notch. If the ground is not 100%, it will knock that whole bank, or partial fire that side, I have seen some weird things happen without that ground. DO NOT underestimate that ground wire. Or any ground on the fuel/timing ignition. All the boxes should have the same ground potential. Get the meter out and start checking ground to ground...the IDM, the PCM, the VC gaskets.

Do you have the ground for the PCM in tact?

 

[Hybrid]

I'm not sure what you mean when you refer to the ground, but at this point I'm probably not even thinking clearly anymore.

All I am aware of is one hot (high side) for each side that resides in the centermost pin on each of the valvecover connectors and originating from one of two "switches" in the IDM itself. The individual injector wires themselves act as the ground and are grounded inside the IDM at the same time as the high side for the respective bank is energized. All of this I have ohmed out, and it is all basically zero ohms within the wires themselves. As far as the impedence for the rest of the harness, I ran the multimeter from the square connector near the driver's side valve cover through the high side pin (numbers 11 and 12) for the respective banks of the injectors being tested while probing the individual injector pins with the other lead with continuity being recorded at every single pin including others such as "power feed" and "gnd" among others.........not one issue. The actual impedence for every single injector was between 3.2 and 3.6 ohms from the square connector as well as from the elongated IDM connector when I repeated all these tests at that connector all the way to the injectors themselves with no problems showing. Or when not carried to the decimal place, the meter always read simply 3 ohms.

I buttoned the truck back up and took it out a few hours ago, and sometimes at WOT it will bring some of those cylinders back online. And at part-throttle I can literally feel the truck lunging and surging as injectors continually come in and out, all the while making my ICP gauge in that head dance around dropping around 500psi every time the truck surges forward perfectly correlated to the injector having "fired".

I still have no real leads. But at this point the truck seems to be firing on #5 when it's hot.

I have a high pressure crossover hose, so I am now wondering if for some reason the oil feed line to that head has been pinched or crimped that the high pressure crossover might actually be "backfeeding" the passenger's side head. Interestingly, #5 injector is directly inline with that hose's entrance to the pass side head. The oil was VERY pastey and thick, almost foamy looking in the head after being ejected from the dump spouts. I actually drove the truck to walmart and got oil so I'll change it out just to check.

Any ideas at all are welcome. I still might change out that PCM Tony.

Thanks

 

[Mach1]

Sounds like you have it covered, changing the oil would be a good move. Its where Ford sends you first place with problems like yours.

 

[Vengeance]

Are you running dual hpops?

 

[Hybrid]

Yes I am.


I changed the oil and the truck runs 700% better. It runs smooth as can be, but the scanner still says #1 on contribution test. It must be just slightly low on contribution on #1 because it isn't noticable at idle.

The truck still misses a little going down the road though.

I now believe that my main feed line for the passenger's side head is in fact crimped and the only oil making it to the pass side head is coming through the crossover hose. It is a -6 so it will support the head, but the stock line leaving the hpop going to the driver's side head will not support both heads. I think the passenger's side head has been "running" off of whatever amount of oil could still make it over to it from the driver's side. The presence of air would explain the large pressure fluctuations in my manual gauge as well.

Interestingly the least prominent injector on the contribution testing and the only one that seemed to produce some contribution when using the cut-out box was always #5. I don't think it's coincidence that #5 sits PRECISELY where the crossover hose comes into the passenger's side head. #1 was the most prominent cylinder to fail the contribution and nearly never made any difference on the cut-out testing. It is the absolute farthest from the crossover hose and it's at the highest elevation so if there was entraped air, it would go to #1 the most.

I'm off to change out the passenger's side head feed line from the hpop and see what happens.



/ubbthreads/images/graemlins/crazy.gif

 

[trucktech]

When you get that old hose off, check the fitting in the head as well, that is the smallest oriface and anythig that might have broken loose from inside the hose might get caught there. Let us know what you find.

 

[wackerjr]

which HPOP?

And how long after you installed it did it start to happen?
a bit more info on your mods and a rough Idea of when it all started would help out a ton.


Wackerjr

 

[Hybrid]

Well the hose checked out fine. I blew through it no problem with zero resistance. Then I threaded a piece of electrical wire through it that was roughly the same od as the hose id and it went through without an issue.

As far as the high pressure pumping systems goes, this "missing" has been a somewhat milder issue for nearly 2 years now off and on with me thinking it was injectors even though no injector problems were ever actually found on teardown. That's why at one point I actually put a brand spankin new set of Alliant powers in.............no change. Same old song and dance. This is all on a single high pressure oil pump BTW. This issue has existed for about 2 years on a single hpop, and now seems to have worsened with the introduction of a second pump. The high pressure pumps are not the cause because this issue has been ongoing for QUITE some time now. But they seem to have aggrivated it.

I am still completely astonished how much difference the oil change made. To put it in to perspective, I am now driving the truck again, whereas before, I had parked it because it was completely undrivable. Before the oil change I would be at 1100 or 1200 degrees trying to drive 50mph on the driver's side cylinders.

Interestingly #4 cylinder started to peak up on the contribution testing once or twice. Once again, remember that I personally flowed this entire set to within an amount not discernable with the naked eye. I did this at 5ms and 2700psi ICP as well as at 2ms 1700psi ICP and they always flowed the same and I even changed nozzles on a couple just so they all even "splashed" into the beakers the same as they sprayed. I mean these injectors are PERFECT. 238 across the board all day. The fact that the truck can run so beautifully from time to time is also evidence that the hardware is fine at times, and things like compression and injector flow rates tend to be relatively consistent so I don't think it's either of those accounting for the highly inconsistent "running" of this motor.

I am very concerned about the very rapid and large fluctuations in the ICP read from my manual gauge in the pass side head. It looks exactly like a gauge reading from a line full of air. Like a fuel pressure gauge when something is running out of fuel. I know that when an injector fires on the bench it will pull the ICP down around 200 or so psi, but that's with only one firing at a time, and at low rpms. My truck makes the gauge dance over 500psi at times and at any rpm from say 2000 all the way out to 3000 or more. I just don't see how injectors coming on and off could drop rail pressure like that at such high rpms with the oil volume that would provide from the pump(s).

And for Wacker...

The truck has:

238cc Hybrids
DAC3 PCM
High pressure crossover hose
BB turbo
Studs
Chip
Full fuel system using David's SX pump and feed from tank. (holds 68psi 24-7)
Dahl 150 fuel water seperator pre-pump
No factory fuel filter. Feed lines are Tee'd into each head in stock locations
Regulated return using an aeromotive reg.

All of that has been on the truck through thick and thin as far as running smooth as silk, all the way to running on 4 cylinders with none of those components being changed.

Nothing actually ever gets changed on the truck, it just runs like total crap out of nowhere from time to time, although I'll admit before it was always just a cylinder or two barely off, not 4 entire cylinders completly shutdown.

This last time, the "missing" started just driving down the road...................and hasn't given me a break yet, only worsened until the majic oilchange this morning which got the truck back to a simple one or two cylinders coming up a little low. At least it will make something happen with most of the cylinders now.

As I drive, the truck will have MASSIVE fluctuations in power output while I hold the accelerator completly still. It is more than enough to snap your neck. Sometimes it actually gets cyclic and continues to come ON and back off then O N then back off then OOO NNN very hard everytime to the point that I'm worried about my u-joints. The ICP from the manual gauge goes up by 200-500psi EXACTLY when these spurts of power come on.

I'm still lost guys. Looks like I'll be driving the bone stock X up to Bowling Green this weekend /ubbthreads/images/graemlins/frown.gif .

I'm totally lost here. This is the only machine, piece of electronics or mechanical thing period that I have ever owned that could drag something as simple as firing on all 8 cylinders out for so long.

I've got nothing. ANY help at all is GREATLY appreciated more than you know.

Thanks

 

[Vengeance]

So your saying that the truck is back to the on off thing now? After the oil change or its better now?

 

[Strictly Diesel]

It would be interesting to swap the HPOP lines between sides of the engine, just to make sure the problems doesn't follow a particular port on the pump or hose.

Try swapping the fittings in the heads too (after swapping the lines, testing and swapping back). Maybe one was poorly made and is causing turbulence or oil foaming?

Also, might be interesting to put a mechanical gauge on the low pressure oil system to see if there are low readings or odd fluctuations there?

Can you datalog IPR Duty Cycle and ICP when it's acting up?

Does it behave any different if you run it without the High Pressure Crossover line?

 

[klhansen]

I've read thru this entire thread, and you are definitely thorough in your troubleshooting efforts. BUT, one thing that you haven't mentioned is checking each of the injector circuits (especially the center bank feed) for a short to ground. Some of the members having injector problems have found worn spots on the harness from the body to the engine where it passes over the driver's side valve cover.

It sure seems like an electrical issue to me, but I'm thousands of miles away from you. /ubbthreads/images/graemlins/shrug.gif

I think you mentioned that you don't get a check engine light, but does it come on when you first turn on the key? Maybe the bulb is burnt out. /ubbthreads/images/graemlins/shrug.gif

This one would make me wonder about my sanity. /ubbthreads/images/graemlins/crazy.gif

Good luck with it.

 

[Hybrid]

I have noticed that when I hold the truck at around 2200-2400 or so rpms at between 1000-1500psi ICP right in the nasty spot where it wants to surge along like I'm pulling a trailer that's loaded way too far back and I'm driving over a bumpy road, that if I keep it there long enough I will see a slight wisp of blue smoke every now and then in the passenger's mirror (single exhaust exit at RR quarter like stock). And if I keep my foot still and as the truck continues to surge and the power keeps coming in and out, I will start to see a constant rolling of blue smoke, and then it will grow to a substantial amount of blue smoke rolling out of my tailpipe and following about 25 or so feet behind the truck about 3 or 4 feet around.

/ubbthreads/images/graemlins/shrug.gif


As far as checking for shorts:

I don't think I know how to check the injector circuits for a short to ground. All I could think to do was first starting at the square 42pin connector near the driver's side valve cover, I would use the multimeter continuity setting and place one probe on the high side pin for the respective bank (either 11 or 12), and then put the other probe on the individual injector wires to make sure that each had continuity. I would then switch the tester to read the impedance of the circuit and each and every injector came up between 3.2 and 3.6 ohms from that connector, and later after reconnecting that one and going all the way from the elongated IDM connector to the injectors with the same procedure the results were the same and the impedance was the same between 3.2 and 3.6 ohms for all injectors.

I then thought that maybe if I had an issue with insulation on a wire that the tiny amount of voltage the multimeter sends that a problem wouldn't surface. So I actually ran 120 volts through the high sides and checked that each injector wire read 120 volts with the other multimeter probe placed in the outlet hole opposite the one running through the harness so that I could complete the curcuit with the multimeter reading voltage. The voltage was always spot on what it was at the outlet. I repeated this test with the entire engine harness off of the truck by lighting up each injector wire individually with 120, and then first checking that I recieved it at the other end of that wire, but more importantly, that I did not read it anywhere else. I always got the 120 on the wire I put it on, and never once got it on any other wires so it wasn't "jumping" through the wires at a possible bad insulation spot. EVERY single wire in the harness has been ohmed out individually, and as a complete circuit on the engine with injectors plugged in and I have yet to find even one thing wrong with any circuit on the entire truck.

BTW, my SES light does work. I should also mention that when this first started again this last time 3 or so months ago, the SES would flicker so fast sometimes that if not at night, and with me not starring at it waiting to see it, you would never notice it. At times it would become cyclic when driving down the interstate at constant load and constant everything to the point that at night I could know when to look down just below the tach and within a second or two there it would be, just a flicker so fast that you might think it was a reflection from a streetlight or something. I still to this day cannot figure out what could make the SES do that? Any break in any of the injector circuits would make it illuminate for about 3 seconds or so no matter how quickly the circuit was open.

To put this into perspective, when it started back to the "missing" this past time about 3 or 4 months ago just driving down the road, the truck didn't feel extremely horrable, I could just tell it wasn't 100% running on 8 cylinders although I didn't have a dead miss anywhere either. This lead me to actually check the compression trying to figure out how I could have power loss on a gradient between 0 and 100%. Compression is over 440psi though, not to mention that for the most part except with the possibility of very weird things happening with valves, compression can be considered constant and wouldn't just come and go like this issue. The motor has just over 100k miles on it anyway and it's never run drugs so chances are that it's solid. But about 3 or so months ago when it started down this path again, it was running a single hpop, and when running good (as far as I know on all 8) it would always make just over 400rwhp with very good efficiency. Extremely low smoke emission(looked about the same or less than a truck running a hot program on AD's), very low timing, and egts were the best I've personally ever driven for a truck at 400hp. Then after I started to notice something was off, the hp dropped into the 360's, smoke and egt's climbed and the part-throttle and off-idle control was sporatic and to be honest easily annoying and frustrating to drive with a manual tranny.

So even before the problem got so bad that anyone could tell the truck is flat out missing, it was still dropping nearly 40hp and drivability and efficiency was actually down, not just sotp kind of stuff, but dyno verified.

I need this truck to physically hual me around every single day, and it doesn't look to impressive to show up to a job site in a 1986 CJ-7 or in a nice looking superduty but with a cloud of blue smoke following you and the engine sounding like it's got 4 10lb hammers smacking on the block(sometimes, but not other times /ubbthreads/images/graemlins/crazy.gif ).

I love this truck and had never planned to sell it, but it is totally displacing my entire operation because I keep having to use other people trucks and obviously I haven't been able to tow anything other than a piss-poor job at hualing itself around empty for over 3 months now.

You mentioned sanity........ /ubbthreads/images/graemlins/crazy.gif

I can't trust myself for anything mechanical right now, because I can't tell you even ONE thing that's actually wrong with that truck.....and yet it runs like total hell.

I really appreciate all the suggestions guys. Anyone who's got something please post it because I don't even have anything left that I can think to check.

Thanks