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7.3 Gurus...Got An Issue

monkeyswrench

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Buddy's son's truck. He's a good kid, bad mechanic. Crank, no start, 2001 F250.
Blew an HPOP line, replaced HPOP and lines. Ran fine, mileage sucked. Discovered an oil leak, IPR, replaced, ran for a day, died.
He replaced ICP sensor, no joy.

My phone rings, take the scan tool over and do the basic checks.
-Lift pump pumping
-all plugs plugged in
-rail pressure with ICP 250 cranking (low)
-rail pressure w/o ICP 2300 (big F'n HPOP)
-"buzz" test passed on injectors
-glow plug timer working
-glow plug relay working
-IDM relay working, voltage in and out good
-PCM relay checked as well
-checked engine harness for chafing, all seems good

It had a "Hydra" tuner on it, removed now.
It's like there is no signal triggering injectors. Swapped out a known good IDM, same model number, no change. The only time I've seen a PCM die on one of these the scanner either gave partial info, or no communication. This one's telling me everything, except the problem!

Any ideas wise and tolerant Ford guys?
 

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Try this: from the off position turn the key to run and wait 1 minute. You have to wait 1 minute. Then proceed to start. If it starts, the batteries are no good.
 

monkeyswrench

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Check the engine oil.
Oil was fresh with HPOP, less than 100 miles and still had the "empties" in the bed.
Cam sensor good?
His was a new "Ford", for shits&giggles swapped in an "International" one I keep in stock...no change. That was my first guess, I always had a spare. Forgot that on the list.
Try this: from the off position turn the key to run and wait 1 minute. You have to wait 1 minute. Then proceed to start. If it starts, the batteries are no good.
Batteries load tested good individually. But, vehicle voltage dropped to 10.2 cranking. Disconnected glow plugs, and then drop was to 11.6 cranking. These were vehicle voltages. At the battery about 1/2 a volt higher.
Also chased and cleaned chassis, harness and engine grounds.
 

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@Flyinbowtie is the resident expert.

The only issue I've had with mine was with the injector harness...

The valve cover Gasket is actually the harness connector! It can come loose inside the valve cover due to the heat and stuff.

Had an issue with the pressure sensor, but that was it runs ONE minute and dies.

The original cam sensor sucked. Odds are it's been replaced by now.

These things Definitely need good batteries to work properly and having Good oil is up there too! Mine is tough to start when an oil change is due.
 

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Oil was fresh with HPOP, less than 100 miles and still had the "empties" in the bed.

His was a new "Ford", for shits&giggles swapped in an "International" one I keep in stock...no change. That was my first guess, I always had a spare. Forgot that on the list.

Batteries load tested good individually. But, vehicle voltage dropped to 10.2 cranking. Disconnected glow plugs, and then drop was to 11.6 cranking. These were vehicle voltages. At the battery about 1/2 a volt higher.
Also chased and cleaned chassis, harness and engine grounds.
My batteries tested the same... Give that technique I mentioned earlier a try. You start it after the glow plugs have cycled. My 2002 7.3 it was a minute before the glow plugs cycled off. Got new batteries and haven't had a problem since and that was 30K miles ago.
 

Mototrig

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Cam sensor good?
X2 for cam sensor.

And running well with poor milage check the EBP tube and diagram for soot buildup.

.....and only use OEM sensors.

When a high pressure oil line is replaced it takes a good 10-15ish miles of driving to clear up the air in the high pressure oil system. It will run rough until all the air is purged.





For future reference:
All pulls should be made with oil temp above 160° in 3rd gear on the freeway from 1800-3000 RPM or while pulling a trailer.

Get a scan tool that reads live data (i.e. Torque Pro $20, auto ingenuity, snapon, ect) and do an IPR duty cycle test while in the stock tune and all air is out of the oil system. The IPR should not read any higher than 42% at 2400-3000# ICP under a load (3rd gear pull on the freeway). Any lower than 2200# could mean weak HPOP or injector o-rings leaking. Any less than 42% IPR with good ICP could be a bad IPR or loose IPR nut or bad pigtail.

An easy check to see if ICP sensor is bad, at idle read live data and pull the ICP plug. At idle ICP is 480ish (IPR 9-12%). When the plug is pulled the system will default to 700# ICP. If you perform this test with these results then ICP sensor is good. If ICP is 700# when at idle with ICP plugged in from start up then bad ICP sensor or pigtail. (Side note, when you pull the ICP plug and the system defaults to 700 it will stay at 700 even after you plug the ICP back in. You have to shut the truck off to reset it)

Fuel pressure should be checked at the fuel filter bowl AFTER the filter (Lower fuel fitting I believe) no lower that 45# under a load.

Exhaust back pressure (EBP) should read between 14-19# under a load. If not a smooth reading or numbers outside these parameters then bad EBP sensor or clogged EBP tube.

There's a lot more basic stuff but this is what I can remember off hand. Hope this helps.
 
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Here is another very important piece of information whenever removing the HPOP reservoir. Only use an oem Ford gasket. All other gaskets will cause the bolt tab to break and to fix that the whole front cover has to be replaced.
 
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monkeyswrench

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X2 for cam sensor.

And running well with poor milage check the EBP tube and diagram for soot buildup.

.....and only use OEM sensors.

When a high pressure oil line is replaced it takes a good 10-15ish miles of driving to clear up the air in the high pressure oil system. It will run rough until all the air is purged.





For future reference:
All pulls should be made with oil temp above 160° in 3rd gear on the freeway from 1800-3000 RPM or while pulling a trailer.

Get a scan tool that reads live data (i.e. Torque Pro $20, auto ingenuity, snapon, ect) and do an IPR duty cycle test while in the stock tune and all air is out of the oil system. The IPR should not read any higher than 42% at 2400-3000# ICP under a load (3rd gear pull on the freeway). Any lower than 2200# could mean weak HPOP or injector o-rings leaking. Any less than 42% IPR with good ICP could be a bad IPR or loose IPR nut or bad pigtail.

An easy check to see if ICP sensor is bad, at idle read live data and pull the ICP plug. At idle ICP is 480ish (IPR 9-12%). When the plug is pulled the system will default to 700# ICP. If you perform this test with these results then ICP sensor is good. If ICP is 700# when at idle with ICP plugged in from start up then bad ICP sensor or pigtail. (Side note, when you pull the ICP plug and the system defaults to 700 it will stay at 700 even after you plug the ICP back in. You have to shut the truck off to reset it)

Fuel pressure should be checked at the fuel filter bowl AFTER the filter (Lower fuel fitting I believe) no lower that 45# under a load.

Exhaust back pressure (EBP) should read between 14-19# under a load. If not a smooth reading or numbers outside these parameters then bad EBP sensor or clogged EBP tube.

There's a lot more basic stuff but this is what I can remember off hand. Hope this helps.
Was using my old OTC scanner. Took it to do the buzz test, and check parameters...was hoping to see an obvious open or shorted circuit...no dice.
The ICP is making a difference, but only cranking pressure since no start condition.
Did you check to see if that stupid stamped nut that holds the sensor on the IRP didn't fall off?
Stamped nut was intact...looked to make sure plug was in.
 

Mototrig

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Was using my old OTC scanner. Took it to do the buzz test, and check parameters...was hoping to see an obvious open or shorted circuit...no dice.
The ICP is making a difference, but only cranking pressure since no start condition.

Stamped nut was intact...looked to make sure plug was in.
Seeing ICP during cranking is good. Now check 2 more things while cranking:
1) Fuel injector pulse width
2) Check for RPM

If you get a fuel injector pulse width reading while cranking then the truck is obviously seeing good parameters everywhere in order to fire off the injectors.... with the exception of fuel pressure which the truck's computer does not monitor.

If you get RPM while cranking then that is an obvious sign that the cam sensor is working properly. If no RPM then I would suspect cam sensor or wiring.
 
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dread Pirate

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Have nothing new to add, but my wife had an odd deal in our 99 last week. Just shut off on the freeway. Nothing made sense and out of frustration I told her and my son to just disconnect the batteries and wait 2 minutes. Pos fired right back up. I still have no idea wtf happened?
 

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Have nothing new to add, but my wife had an odd deal in our 99 last week. Just shut off on the freeway. Nothing made sense and out of frustration I told her and my son to just disconnect the batteries and wait 2 minutes. Pos fired right back up. I still have no idea wtf happened?
I'm gonna guess it happened in the rain?
 

endobear

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Have nothing new to add, but my wife had an odd deal in our 99 last week. Just shut off on the freeway. Nothing made sense and out of frustration I told her and my son to just disconnect the batteries and wait 2 minutes. Pos fired right back up. I still have no idea wtf happened?
Loose battery connection..
 

monkeyswrench

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Seeing ICP during cranking is good. Now check 2 more things while cranking:
1) Fuel injector pulse width
2) Check for RPM

If you get a fuel injector pulse width reading while cranking then the truck is obviously seeing good parameters everywhere in order to fire off the injectors.... with the exception of fuel pressure which the truck's computer does not monitor.

If you get RPM while cranking then that is an obvious sign that the cam sensor is working properly. If no RPM then I would suspect cam sensor or wiring.
RPM read fine, pulse width commanded was .63 I think? Didn't pay too much attention, just wanted to see if it had any...like checking spark I guess.

No smoke, no sputter...no joy. The injector/UVC connections are getting signal via wiring, but I don't know if the PCM is actually telling the injectors to fire...I see pulsewidth on the scanner, but no semblance when cranking.
 

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RPM read fine, pulse width commanded was .63 I think? Didn't pay too much attention, just wanted to see if it had any...like checking spark I guess.

No smoke, no sputter...no joy. The injector/UVC connections are getting signal via wiring, but I don't know if the PCM is actually telling the injectors to fire...I see pulsewidth on the scanner, but no semblance when cranking.
Did you try waiting a minute with KOEO then start it after the minute without resetting the key to off?
 

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From the service manual:

A 1-6 mS fuel pulse width (FUEL PW) will be sent by the PCM to the IDM if system voltage does not go below 7 volts during cranking, engine cranking speed is above 100 rpm and injection control pressure is above 3450 kPa (500 psi). Even though a 1-6 mS fuel pulse width is shown on the NGS to be sent to the IDM, it is possible the IDM did not get the signal, due to a fault on either the CID or FDCS circuits or even the IDM. Note that low fuel pressure or no glow plugs could still be the cause of the No Start or Hard Start condition. A 0.60-ms fuel pulse width (a no fueling pulse) will be sent by the PCM when a sync pulse has not been received from the CMP sensor and if insufficient injection control pressure is present. This 0.60-ms fuel pulse width will not allow injectors to be enabled, but does keep the IDM and PCM synchronized until sufficient injection control pressure is realized.

It sounds like .63 is a "no fueling pulse", not that any of this is anything I have ever worked on!
 

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From the service manual:

A 1-6 mS fuel pulse width (FUEL PW) will be sent by the PCM to the IDM if system voltage does not go below 7 volts during cranking, engine cranking speed is above 100 rpm and injection control pressure is above 3450 kPa (500 psi). Even though a 1-6 mS fuel pulse width is shown on the NGS to be sent to the IDM, it is possible the IDM did not get the signal, due to a fault on either the CID or FDCS circuits or even the IDM. Note that low fuel pressure or no glow plugs could still be the cause of the No Start or Hard Start condition. A 0.60-ms fuel pulse width (a no fueling pulse) will be sent by the PCM when a sync pulse has not been received from the CMP sensor and if insufficient injection control pressure is present. This 0.60-ms fuel pulse width will not allow injectors to be enabled, but does keep the IDM and PCM synchronized until sufficient injection control pressure is realized.

It sounds like .63 is a "no fueling pulse", not that any of this is anything I have ever worked on!
Huh.....I learned something today. I always assumed any reading was good. Thanks for this 👍👍
 

monkeyswrench

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Did you try waiting a minute with KOEO then start it after the minute without resetting the key to off?
Not intentionally, but did yesterday. I'm not with the truck today. Yesterday I had left the key on so I could watch the glow plug function on the scanner. Was looking to see both if they worked, and if the voltage was an issue.
I remember some years could still have a working tach, and a bad CPS...could this be reading rpm on the scanner from another source? Can the cps give a "weak" signal? Wondering if it needs another cps, or if I have a loose wire in the pigtail.
From the service manual:

A 1-6 mS fuel pulse width (FUEL PW) will be sent by the PCM to the IDM if system voltage does not go below 7 volts during cranking, engine cranking speed is above 100 rpm and injection control pressure is above 3450 kPa (500 psi). Even though a 1-6 mS fuel pulse width is shown on the NGS to be sent to the IDM, it is possible the IDM did not get the signal, due to a fault on either the CID or FDCS circuits or even the IDM. Note that low fuel pressure or no glow plugs could still be the cause of the No Start or Hard Start condition. A 0.60-ms fuel pulse width (a no fueling pulse) will be sent by the PCM when a sync pulse has not been received from the CMP sensor and if insufficient injection control pressure is present. This 0.60-ms fuel pulse width will not allow injectors to be enabled, but does keep the IDM and PCM synchronized until sufficient injection control pressure is realized.

It sounds like .63 is a "no fueling pulse", not that any of this is anything I have ever worked on!
Sure as hell sounds like the CPS 🤨
 

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Not intentionally, but did yesterday. I'm not with the truck today. Yesterday I had left the key on so I could watch the glow plug function on the scanner. Was looking to see both if they worked, and if the voltage was an issue.
I remember some years could still have a working tach, and a bad CPS...could this be reading rpm on the scanner from another source? Can the cps give a "weak" signal? Wondering if it needs another cps, or if I have a loose wire in the pigtail.

Sure as hell sounds like the CPS 🤨
Typically a bad CPS will just quit, however there are some cases were there are CPS's that have intermittent problems.
Some model years will still have a tach signal with a bad CPS, just can't remember what years.
Possibly try a battery swap? My 02 had a long crank no start symptom and was like it had no signal to the injectors to fire. Batteries did test good but for some reason the batteries didn't have enough in them to power up the IDM until the glow plugs fully cycled to off.
Last week was cold and maybe that cold spell did some damage to the batteries? Mine happened in the winter time as well.
 

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Did you see if it will fire on WD40? Will confirm fuel fault, assumed from your posts the cigars are all lighting up. All you need to hear is a pop or two.

You can go backward from there if it fires, sounds like a bad CPS to me, since you are getting a cam signal(RPM reading).

At 10ish volts cranking I'd have cleaned and charged the shit out of the batteries, they are fuckers about voltage. Make sure you don't have one weak one pulling the whole line down as it drops past 10 and falls on it's ass after cycling the glowsticks and when cranking.
 

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how much fuel in the tank, when the pickup in the tank rots and falls off, you will start having issues when fuel gets low
 

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Was that ICP aftermarket or motorcraft?
 

monkeyswrench

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ICP and IPR were both Motorcraft

Tank was showing 3/4, dumped another 10 just in case...lift pump is pumping clean and clear.

Will "try" to fire on WD-40...had them need a little "kick" to build rail pressure before. Checked with scan tool...has lots of pressure cranking.

IDM was swapped with a known good one.
 

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I've never had success on firing a diesel with WD-40 as you need a vapor to ignite and to much liquid in the cylinder will bend a rod. Best success outside of starting fluid has been a rag with a splash of gas on it held at the intake behind the air filter.
 

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I keep hearing battery voltage... So I would hook up a set of jumpers and try
 

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I keep hearing battery voltage... So I would hook up a set of jumpers and try
It may not work... my truck was doing the same thing. Cranking but just no injector fire (electrical problem). Checked voltage and compared to my other 02 and were very close in results. Hooked up jumper cables and no start. Charged batteries and no start. Did key on engine off and after a minute of waiting turned to start and it started. It doesn't make sense but it started. Duplicated everything a few times to confirm and ended up buying new batteries. 30k miles later I haven't had a problem. Now that I think of it it the problem started the first week of a cold spell. The cold probably messed up the batteries somehow yet they tested good.
 

monkeyswrench

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check injector Orings you need 400 psi to fire injectors
Plenty of pressure. Had one a few months back that could only start on ether...on the scanner, as it tried to kick, it would spin fast enough to overcome the 3 leaking injectors. That's when I made the the doodad that pressurized the oil gallies with shop air. You could hear the injectors farting in the valve covers😁

It may not work... my truck was doing the same thing. Cranking but just no injector fire (electrical problem). Checked voltage and compared to my other 02 and were very close in results. Hooked up jumper cables and no start. Charged batteries and no start. Did key on engine off and after a minute of waiting turned to start and it started. It doesn't make sense but it started. Duplicated everything a few times to confirm and ended up buying new batteries. 30k miles later I haven't had a problem. Now that I think of it it the problem started the first week of a cold spell. The cold probably messed up the batteries somehow yet they tested good.
First cold snap up here is a killer on batteries. I don't know the chemistry of the issue, but cold kills them. He may "borrow" the batteries out of his dad's truck tonight and test with them.
 

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ICP and IPR were both Motorcraft

Tank was showing 3/4, dumped another 10 just in case...lift pump is pumping clean and clear.

Will "try" to fire on WD-40...had them need a little "kick" to build rail pressure before. Checked with scan tool...has lots of pressure cranking.

IDM was swapped with a known good one.
Ah, Just re-read your first post...I got nothing. Very surprised after everything its not running.



Have nothing new to add, but my wife had an odd deal in our 99 last week. Just shut off on the freeway. Nothing made sense and out of frustration I told her and my son to just disconnect the batteries and wait 2 minutes. Pos fired right back up. I still have no idea wtf happened?
That is most likely due to an aftermarket (non Motorcraft) ICP caused by RF radio waves. Ya I know it sounds crazy. I recently put a CB radio in and
had this very thing happen...as soon as I broadcasted the engine would die every time! Went to Motorcraft...no more problem. Since then I have changed out
the IPR and CMP with OEM as well.
 

rivermobster

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I keep mine tuned to "full power mode" all the time. It runs So rich like that, it absolutely will Not start at altitude with snow on the ground cold! 🤣

I Have used starter fluid on it. But ...

Just put on second's worth on the air filter and take your time getting back to the key to let most of it evaporate.

Do not crank and spray at the same time!!!

It doesn't take much at all. You can Easily cause bigger problems with starting fluid.
 

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I keep mine tuned to "full power mode" all the time. It runs So rich like that, it absolutely will Not start at altitude with snow on the ground cold! 🤣

I Have used starter fluid on it. But ...

Just put on second's worth on the air filter and take your time getting back to the key to let most of it evaporate.

Do not crank and spray at the same time!!!

It doesn't take much at all. You can Easily cause bigger problems with starting fluid.
DP tuner? F6 is it?
 

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Did you see if it will fire on WD40? Will confirm fuel fault, assumed from your posts the cigars are all lighting up. All you need to hear is a pop or two.

You can go backward from there if it fires, sounds like a bad CPS to me, since you are getting a cam signal(RPM reading).

At 10ish volts cranking I'd have cleaned and charged the shit out of the batteries, they are fuckers about voltage. Make sure you don't have one weak one pulling the whole line down as it drops past 10 and falls on it's ass after cycling the glowsticks and when cranking.
A good battery will bottom out around 11.4 when loaded, 10 volts es no bueno.
 

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Does anyone know where the stupid buzzer in the dash is? I hate that damn thing goes off randomly in my '02
 

monkeyswrench

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Does anyone know where the stupid buzzer in the dash is? I hate that damn thing goes off randomly in my '02
I think it's mounted under the radio, behind the AC controls. Factory radio, no problem...aftermarket mounting may make it a pain.
 

monkeyswrench

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Replace the CPS....
Listed above...the kid had a Ford dealer (new) one in it, I swapped in an IH one.

Leaning towards pigtail or wiring from there into harness. I'll probably end up ohming the pin outs to the plug on the driver side, and if needed, there to pcm.
 

SBMech

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Listed above...the kid had a Ford dealer (new) one in it, I swapped in an IH one.

Leaning towards pigtail or wiring from there into harness. I'll probably end up ohming the pin outs to the plug on the driver side, and if needed, there to pcm.
Sounds like it. You have covered all the known "replaceable" stuff as far as I have read. Broken wire sounds like the right direction.

This is not the years where the bulkhead connector fails and burns is it? Not a Ford specialist, I work on everything, so I know a few things....but far from a dealer master.

I am gonna ask the stupid question, no faults in any mode right from a scanner?
 

monkeyswrench

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Sounds like it. You have covered all the known "replaceable" stuff as far as I have read. Broken wire sounds like the right direction.

This is not the years where the bulkhead connector fails and burns is it? Not a Ford specialist, I work on everything, so I know a few things....but far from a dealer master.

I am gonna ask the stupid question, no faults in any mode right from a scanner?
I don't think this one has bulkhead issues, but hell, I'll Google it.
No fault codes present or pending...F'rs just evil!
 

monkeyswrench

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Ohming out harnesses has to be one of the most boring and unrewarding activities ever invented. Hope you find the problem.
If it solves the issue, will be better than winning the Super Bowl 🤣 He's a good kid, otherwise he'd be on his own on this one.
 
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