[Superduty Tank]

I've looked for help ideas from multiple forums--noticed this one seems to be the most active and skilled-so, became a new member and looking for help--long intro to provide all the information as I've been doing a lot for the past month plus the truck has been down. I'm limited on my knowledge of all the terms--been learning, so may not always use the correct abbreviations below...
RIG: 99.5 7.3 superduty, 317K--taken well care of since new.
PROBLEM: has run great--sat for a few days and then went to start and just cranks over and no smoke or attempt to start. Inovia tester showed P1280 for low injection fuel pressure, plus the code for the turbo since years ago i deleted the preheat system on that when doing the WW2 upgrade. Dash lights when key on --all go off but the Service Engine Soon light--glow cycle is normal, oil pressure shows on gauge at 3/4 mark like normal when cranking, tach bumps when cranking to show systems are good at PCM/CPS?.

1. I looked online and found the ICP sensor was the most likely issue; no leaks on ours--pulling the connector didn't change attempt to start results; bought new sensor and connector wire and installed; no change.
2. Cam Position Sensor; had one in the glove box; installed--no change in attempt to start.
3. checked the fuel filter; great--only a few months old; while at it checked the by pass pressure valve and when re-installing the fuel line the threads broke off in the compression nut--so ordered a new one, cut the line end off and did the flare repair--tough to do in such a tight spot; BUT-now we know the spring and valve are good.
4. Fuel pump; removed and blew compressed air back through the line into the tank and heard it rumbling for awhile; cant due the fuel tank drop and inspection and hook mods as tank is 95% full.
5. Next checked HPOP oil level; all good. But while at it replaced the oil sensor on top.
6. Fuel pressure control valve (?) at the base of the HPOP: replaced that as well wire connector--no change in attempt to start.
7. IDM: accessed and found it was missing the side plug and showed moisture inside so replaced with a high voltage one from Diesel Tech in TN--no change in attempt to start, but based upon conditions would have failed anytime soon. so glad we found and replaced that.
8. PCM: some sites showed this could be an issue; so replaced as well since this is our snow plow truck and storms were coming --BUT: no change--in attempt to start.
9. Fuel Injectors: was concerned of potential oil pressure issue keeping injectors from firing due to bad o-rings; didn't want to do all this work but have a full set on standby; so did the injectors, valve cover gaskets and wiring harness under the covers along with glow plugs. Orings on a few were slightly abraded but saw nothing of concern; inspected harness connectors and took apart at the same time and found nothing wrong, assembled with dielectric grease--note; years ago put the cover over the harness wires by valve cover due to online comments about wear--none shows on our wires. Purged cylinders well--pressurized oil and fuel; still no start or even a puff or pop. Buzz test of old injectors before pulling was good and new ones just the same.
10. Re-inspected the IDM and PCM pins and connectors; took back of connectors off to inspect wires and clean; found nothing and no rubs; added dielectric grease to improve connectivity; tried to start and no changes.
11. Inspected wiring harness on engine and have found nothing; wraps all good and still no start.
12. replaced the sensor in front of the HPOP--i believe that is related to exhaust pressure.
13. Diesel Tech told me about the Forscan testing system and asked us for data so they could offer some assistance; bought and ran the testing and it showed the same codes as the inovia (note; cleared codes many times with Inovia and Forscan and they both always come back with same codes. Other Forscan data; about 16% fuel before start then up over 60% when cranking, fuel pressure builds to about 2,300 psi plus, CPS is shown as good, engine plugged in oil temp about 86' when 32 outside. Mass fuel shows well-up to 57mg, battery voltage good and strong--freshly charged up both batteries before each start attempt. Diesel Tech stated our starter rpm was slow--120rpm; has been normal for this starter and always started right up; but, since i had a new one sitting on the back seat; installed that and it now cranks 160rpm plus--truck even new it was never that fast. They said the scan data indicates the HPOP and related valve are working correctly. Still no start--have been very grateful for Diesel Tech's assistance and service!
14. Just replaced the PCM relay, IDM relay and PCM diode; no start still--just fast cranking, no smoke or rumble. Early on, checked through both fuse panels as well and none were a problem--the fuel bowl heater fuse and all looked great too.

So, I'm very weary and have a big hole in my wallet; we live in rural Idaho and over an hour to a dealer if i chose that route with a tow--so have had to do what i could and have appreciated all the wisdom and prior comments from this forum and many others. I chose to spend the $ since the truck is still running strong and is a keeper, till we can finish the HJ60 diesel Land cruiser and put the superduty into back-up rig mode (fire wood and snow plow).

I've looked into replacing the wiring harness but can only find the top of engine harness--haven't found the from engine to PCM/IDM harness. i cringe thinking about all the work to do it as well, let alone more cost.

For the truck to stop working suddenly indicates electrical....but with all the 'parts' replaced except wiring and the scan data looking good--none of this is making sense to my limited understanding. Diesel Tech has my third scan to review as they wanted to see Fuel Injector Pulse width information.

I see complex comments on this forum about breakout box and pin testing and such...i've looked at wiring diagrams...that level of testing is beyond my competency.

Well--any additional ideas? Any links/suggestions for a full wiring harness for top of engine AND PCM/IDM?

I greatly appreciate your help!!

 

[Oneof6]

Good morning, you certainly have a ongoing frustrating and expensive ordeal. My advice would be to stop throwing parts and money at it. You have done many overlapping serious R&R's of systems and parts with what seems to be no solid evidence that each, or any, was the root cause. That parts blast introduces a new level if doubt without really checking off any category. Overwhelming.
So, obviously a new approach is required. Getting codes is great, on a non-starter all you will really get are stored codes and some testing data that you already have.
Approach, start breaking it down into individual systems and proving out individual systems before moving on to the next. Like fuel, for instance and only one of many, it's one thing to blow reverse air into the tank and quite another to have/pump actual fuel all the way to and through the filter and to the engine, prove that out. Then check it off and focus on the next system.
Lots of issues can cause an "instant off" no restart condition, like IPR coil or connection/wire.
Even things like smell can give one vital information, do you smell fuel at the exhaust when you crank it over? If you dont you should.
You obviously have great perseverance to have taken it this far. Like anytime one gets lost it always best to sit down, calm down, and make a plan of linear direction to identify where you are at the moment and where to go from there.

 

[olddieseldude]

When you crank the engine over what displays are you seeing on the dash; lights, tach, etc?

 

[Maryland dieselnick]

Box up all of those parts. I’ll get you my address.
I only saw one code you listed. If multiple codes are present please list them.
What is your injector pulse width?
I what you to look for 12 volts at the IPR at the harness that plugs into the High Pressure Oil Pump.
There is a drain pump in front of engine from the fuel bowl. Attach a hose to it. Attach a weight to it. Put it in a jug. Access the back of fuel bowl. Have someone turn the key on. It should gush fuel like a race horse peeing.
Did you change your oil after doing injector oring change? What is your oil level?
There is an Allan head plug on top of the high pressure oil pump tank. Take it out. How much oil is in there? Should be about 1/4” below rope of tank.
Do a voltage drop test on the glow plug relay. Look for voltage deviation of voltage coming out of relay vs going in when activated.
That will keep you busy for awhile. I will check back in on you.

 

[Superduty Tank]

Box up all of those parts. I’ll get you my address.
I only saw one code you listed. If multiple codes are present please list them.
What is your injector pulse width?
I what you to look for 12 volts at the IPR at the harness that plugs into the High Pressure Oil Pump.
There is a drain pump in front of engine from the fuel bowl. Attach a hose to it. Attach a weight to it. Put it in a jug. Access the back of fuel bowl. Have someone turn the key on. It should gush fuel like a race horse peeing.
Did you change your oil after doing injector oring change? What is your oil level?
There is an Allan head plug on top of the high pressure oil pump tank. Take it out. How much oil is in there? Should be about 1/4” below rope of tank.
Do a voltage drop test on the glow plug relay. Look for voltage deviation of voltage coming out of relay vs going in when activated.
That will keep you busy for awhile. I will check back in on you.

 

[Superduty Tank]

Hello and thank you all for your timely reply this AM; please see updates and information as follows:
Oneof6: Yes, you are correct about variables, focused or confused and enduring---i was aware of those factors hence taking over a month to get this far-focusing on the highest likely parts before going onto more expensive or high labor tasks--then checking each time multiple times before moving forward. Many parts we already had on hand for 'someday' and also concerns with the supply chain mess--and had saved up for such a day as this. Completing a whole 'system' as you say makes sense--and we did as best we knew how to with what we had and then as we learned did more-like a lot of other areas in life; we encounter challenges that cause us to learn but that we can't know and learn ahead of time--around here and online i sought out help and followed all the online information i could find which brought me to this point. I'm ok with the costs--not preferred but now with 329K on the odo--and still running strong on mostly stock sensors and such--felt it was worth the going through so when this rig is parked as a back-up i know its solid and fresh.
To your questions; smell at the tail pipe--absolutely nothing...which is rare for a diesel . no evidence of fuel and we were careful on the fuel injector replacement with cylinder cleaning/purging so no oil there to give it even a rumble or smoke.

Oldiesdude: thank you for all the attachments--printed and saved and read through much of it as well.
To your questions; key on dash shows all idiot lights then they cycle off to leave the SESoon, battery symbol with gauge showing volts and oil can until after about 25 seconds of cranking the oil gauge comes up to 3/4 just like when engine is running. Wait to start cycles normally and goes out. When cranking; tach has a micro bump, voltage drops a bit on gauge, lights mostly out as usual--oil pressure comes up on engine.

Maryland dieselnick; Thank you--to your questions: no oil change after replacing the injectors; not due yet--topped off to just above full when those were finished. HPOP is just below the bolt as you noted--same both times checked over the past month. Injection control solenoid at back of HPOP: when this was replaced we also replaced the connector and inspected the wires as best we could but limited due to factory wrap. Did the voltage key on test and it was 11.4V--likely a bit low as the batteries were still charging from recent crank testing. Fuel flow test you requested from bowl drain; tested 3 times and each time strong flow till the 20 second cycle shut off occurred.

codes: been cleared over half dozen times by both scan tools; still P1280 and P0475 keep coming back---awhile back 1670 but that cleared away. Fuel injection pulse width; climbing and 3.03ms at time of screen shot--in the past have seen it about 5.

Forscan showed all glow plugs and relays to be good and working about 98%.

thank you all!
I've attached this AM's 3rd Forscan cranking screen shot for more detailed information--being third time voltage was a bit low but early AM was about 12.8V key on and 11.6 during cranking.

I look forward to more input and wisdom to get this beast alive and on the road.

take care,
MG

 

[Maryland dieselnick]

Stop what you are doing. FULL STOP. Oil should have been changed at time of injector work. Diesel fuel flood the cylinders when you pulled the injectors. It ran past rings and into crankcase. Change oil, filter and suck oil out of the high pressure pump oil tank. Refill and do nothing else until then.
Then find out why you referrance voltage is not 5volts. Check it at CPS, ICP.

Get me cranking speed.
Batter voltage before and during cranking.
Get me ICP while cranking in PSI.
Get me duty cycle while cranking.

 

[Superduty Tank]

Thankyou-easy enough to do; most of the info you requested is in the Forscan screenshot above and my txt comments above that.

take care

 

[Oneof6]

It's significant that with " 25 second" start cycle attempts there is no reported scent of fuel at the exhaust " absolutely nothing "

That would indicate either no fuel to the injectors or injectors not actuating/firing. 25 seconds is a lot of fuel left uncombusted it HAS TO go out and you WOULD smell it, if the injectors were actuating. Have you tried unplugging the ICP and letting it default to 500 psi?

 

[Maryland dieselnick]

They either default to 700 or 725 depending on the factory PCM flash.

Again.., Use test light at IPR harness to verify it getting juice.

A scanner can post erroneous ICP pressure as it’s reading what the PSI should be if the ramped up duty cycle was achieved under crank no start.

 

[Maryland dieselnick]

I missed you other codes P0475 is exhaust back pressure valve malfunction. That going to be a delete pedestal or circuit malfunction. Nothing to worry about unless you do have the original pedestal and the valve is stuck shut, then it’s a major problem.
P01670 is a feedback code probably from when you were messing with your IDM.
Do the all built in self tests in your scanner.

 

[klhansen]

You're trying to record too much (and some of it irrelevant, such as EPC, which is transmission related).
Start over, recording ICP pressure, IPR duty cycle, Engine RPM, and injector pulse width ONLY.
IPR duty cycle at 35% looked OK, as did Engine RPM (min of 100), ICP was above the 500 psi minimum. Injector Pulse Width also looked in-range.
One thing that stood out as odd was Vref of 2.53V. It should be very close to 5V (within ~1/2V). That may have biased all the sensor signals, as it's the basis for the sensors.
Also the IPR duty cycle is only what the PCM tells the IPR to do, not what it's actually doing. Verifying the IPR is getting 12V on the feed wire is a good suggestion. The PCM provides a pulsed ground to make the IPR close and drive injector pressure up. If it's not getting 12V, then it can't close.

 

[Maryland dieselnick]

Hey what are you doin’ Kev???
I liked his chart!! All of those colors are groovy!!

 

[Maryland dieselnick]

Side notes:
Oneof… Ms= Millisecond. Milli= 1,000 so
3 Ms = .003 second NOT .25 second.

Superduty, You wrote that your scanner said blow plugs were good at 98%. Is your truck California emissions equipped. Those trucks and Excursions have glow plug monitors so if your truck is not, don’t even click on glow plugs. I think I read it was 72 degrees out so you don’t need them in that heat unless your cylinders are ragged out and have low compression. Well, I correct myself… You do need them in a big way. Did you remember to those little rascals back in,Guy?
Do that voltage drop test I told you to do if you don’t have California emissions.

 

[klhansen]

Hey what are you doin’ Kev???
I liked his chart!! All of those colors are groovy!!

Yeah the colors are cool, but trying to record too many things slow down response time.
What are your thoughts Nick, on his Vref being less than 3 V when it should be 5 V?

 

[Superduty Tank]

Yeah the colors are cool, but trying to record too many things slow down response time.
What are your thoughts Nick, on his Vref being less than 3 V when it should be 5 V?

 

[Superduty Tank]

Update; oil changed and did the fuel filter as well so clean baseline; heard some people had issue with fuel bowl heater element blowing fuse creating issues; took the factory original out and in doing so found the plug had fallen off the prong: cleaned bowl and installed new heating element.

no change on attempt to start. Starting voltage was 13.8v

Maryland dieselnick; don’t recall if CA emissions or not when bought in 2000-temp you noticed was engine oil temp with it plugged in; outside was around freezing.

Klhansen; thankyou for joining in-sorry about transmission data-Diesel Tech also asked us to delete that and I forgot—attached are screen shots this AM—no Smoke, smell or start.

The scan is more data than you are asking for as Diesel Tech wanted more detailed info.

I will try to do more voltage testing—don’t really know much about how to do that-but will try

2 screen shots attached; first is after 15 seconds of cranking the second about a minute, from today.

Really appreciate all of your input!!

 

[klhansen]

I still think that your 2.5V Vref signal is a problem. It should be near 5 V at all times. Your ICP and IPR are tracking fairly well, high IPR duty cycle with high ICP at the same time is the way it's supposed to work. But with ICP at over 500 PSI, it should fire off.
Can you pull codes and post them (again?)

 

[Superduty Tank]

Klhansen; cleared and rescanned codes just now and still same ones; P1280 and P0475.

take care

 

[Maryland dieselnick]

Kevin, Yes I had caught that low vehicle ref. and told him to run that down. Voltage drops are almost always from corrosion but in this system where multiple sensors are on the same circuit, one sensor can drag down the whole circuit. He needs to unplug CPS, ICP, EBP and MAP. He needs to check for 5 volts at each connector. If he finds a low voltage at one connector or connectors, he needs to trace backwards. If he does not, he need to plug one at a time back in and recheck the other connectors in attempt to find the drag down.
One can’t rely on reported ICP pressure and duty cycle with cranking, cranking, because the scanner can pick up on what the PCM is TRYING to achieve.
He needs to clear out all of his PIDs ( Parameter IDs) and just get battery voltage, ICP in PSI, RPM, pulse width.
He needs to record the values before cranking and then during cranking.
He needs to use a test light on unplugged IPR connector to look for juice with key on.
It’s cold where he is. He needs to do a voltage drop test on glow plug relay if it’s not California emissions.
He needs to ohm his glow plugs and injectors.
He needs to stop these long cranks or he is going to fry his starter. He needs to limit to 10 seconds and give 5 minutes to cool.
He never said if the fuel bowl had a filter in it. No filter No start. The is a valve trap door in that tower that won’t let it run if the filter is left out. Yeah, I’ve seen it after hutch mods being done. The rational was, Never have to climb into the engine compartment again because I now have a filter down of the frame.
He needs to look for aeration ( foam ) gushing from fuel bowl when drain is opened with hose attached to drain pipe, with key on.
His back pressure valve malfunction code keeps coming back. I addressed this with him. I told him that he needed to see if a valve delete pedestal was installed and if original was still in place that the valve was in the open position.
Shower and dinner time for me