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-   -   Stumped (https://www.ford-trucks.com/forums/1535644-stumped.html)

axmrdr 04-09-2018 09:59 PM

Stumped
 
I am stumped. My truck died on me a couple weeks ago and I've been scowering threads trying to figure out the problem. First thing I did was change CPS, then changed the IPR, changed the oil, now after changing the ICP I am stumped. Here's a screenshot from AE during last starting attempt.
https://cimg4.ibsrv.net/gimg/www.for...586e42ca46.jpg
I read that the voltage should be 10.5 volts, I took this after cranking for quite a while, I'm sure the voltage was over this when I first started cranking. The first 2 windows were fluctuating and hitting over .85 volts and around 500 psi.
Last year my HPOP was replaced, ICP, IPR,and CPS. I was 1000 miles from home, everything looks like after market except maybe the HPOP, that's why I am replacing with motorcraft parts now.
270k on the engine, 2002, nothing done to injectors, Oil gauge on dash takes several seconds before it indicates good pressure.
Stumped and frustrated, really need to have my truck running, not a lot of diesel mechs around here that I have faith in.
I'd piss on a hot wire if it would fix this truck. What can I check next? Working 72 hours a week presently so my time is limited but I need this baby running.
Thanks for listening

Shattered 04-09-2018 10:13 PM

I had a similar issue with mine, replaced IPR, ICP, etc... came to find out that I had a bad fuel leak that caused it to not start, and when it did it loped bad.
Have you checked to make sure your fuel pump is working?

roozterdvx 04-09-2018 10:24 PM

Just recently went through a no start situation after installing new injectors.
After trying a barage of diagnostics, found the insulation crumbling off the IPR pigtail.
Wires touching each other and shooting my IPR duty cycle to 97%.

Yours is up there too. Around 65% should be fully closed I think...

I found it by checking continuity between the IPR pigtail pins and the 42 pin connector.
If I remember right, pin 24 is positive, red wire and pin 25 is the switched negative, yellow/red wire.

When I tested, I stuck a probe in the pigtail connector on the red wire and the other on pin 24. Got continuity.
Then moved the probe to pin 25 which should have continuity with the yellow/red wire, and I still had connection to red.
At this point I started unwrapping the plastic loom and tape to look for the short.
found it right up closed to the pigtail connector.
With the wires touching, the PCM is commanding the IPR for more pressure but the solenoid isn't getting any juice so ICP wasn't getting high enough to fire the injectors.

Worth a shot...

$18 pigtail from NAPA and she lit.

axmrdr 04-09-2018 10:25 PM


Originally Posted by Shattered (Post 17916375)
I had a similar issue with mine, replaced IPR, ICP, etc... came to find out that I had a bad fuel leak that caused it to not start, and when it did it loped bad.
Have you checked to make sure your fuel pump is working?

Sorry, should have mentioned that the fuel bowl is full. Haven't been able to pick up new filter yet. Batteries were fully charged on the charger.

roozterdvx 04-09-2018 10:26 PM

Here's a little reading for you.
Hope it helps.

https://www.ford-trucks.com/forums/1...-pressure.html

axmrdr 04-09-2018 10:38 PM

Thanks. Will do. I can do electrical. I will report back.

Tugly 04-10-2018 07:37 AM

I would start by pulling the chip. Stock program won't allow the IPR to go over 65%. Oil level? Original sticks would prompt a Cody test.

axmrdr 04-10-2018 08:18 AM

Oil level is good, just changed oil - after truck died. I had the truck towed back to my driveway, shop is full of other projects so I'm relegated to working in the driveway for now..

I'll remove the chip as well, 20 minute job I can do today after work. Since you're here ;-) and you're the AE expert, what option in the drop down window do I select to get AE to see the high fuel pressure, I swore I have done it before but it's been a while since I used AE. I'm reading your AE class thread in between jobs at work but retaining everything that I'm reading is a bit overwhelming.

Presently working 12 hours days but as soon as I can I'll check wiring and do a Cody test. (I'll read up on that).

Tugly 04-10-2018 08:40 AM

There is no fuel pressure sensor on the truck, I bought an analog gauge to read that - along with two pyrometers. The closest you get to "high fuel pressure" sensor is the ICP, and you have that. The Fuel Pulse Width #1 is a bogus reading, you want Injector Pulse Width. Use just one PID per sensor - like ICP PSI instead of ICP volts - PSI is a calculation based on the volts. I have no idea what electronic pressure control is - 15 is such an odd number. BARO is not needed to troubleshoot a no-start. It's just used to verify EBP and MAP sensor accuracy - a whole different test parameter.

axmrdr 04-10-2018 10:43 AM

Gotcha thanks.

axmrdr 04-10-2018 12:49 PM

After combing through many other threads describing fuel pressure related issues I realize that I may have shot myself in the foot. In the process of replacing the IPR I think I put the coil on backwards. Yes, I'm aware that I am an idiot. Admitting that is the first step to recovery I'm told.

When I get home tonight I'll be sure to 'check and correct' and post back results. If that doesn't fix it then I'll perform previously given advice.

hydro man 17 04-10-2018 07:29 PM

I must be missing something, but if the screen shot was taken while trying to start I see zero fuel pressure. The pump is electric so there should be ~60 PSI whether the engine is running or not.

roozterdvx 04-10-2018 08:00 PM


Originally Posted by hydro man 17 (Post 17918264)
I must be missing something, but if the screen shot was taken while trying to start I see zero fuel pressure. The pump is electric so there should be ~60 PSI whether the engine is running or not.

There is no fuel pressure sensor.

AllaboutMPG 04-10-2018 08:40 PM

That screen shot only has 417 for icp. PCM wants to see at least 500 to fire. You said you've seen around 500, may not be be getting enough icp. Change your settings on AE, charge batteries, and try again. We'll go from there.

AllaboutMPG 04-10-2018 08:41 PM

Man do i miss the full site:-arrgh

axmrdr 04-10-2018 10:07 PM

OK, corrected the incorrectly installed IPR coil and tried to start it. Failed.
Removed the dptuner and grabbed the computer for some data collection. It was dark by now so I had my wife start the truck so I could check the tailpipe. Grey/white smoke.
Didn't get chance to check wiring yet or voltage at IPR coil leads.
https://cimg7.ibsrv.net/gimg/www.for...d7facc2e7f.jpg

Tugly 04-11-2018 08:09 AM

That is a vast improvement - the engine is trying to fire. The Fuel Injector Pulse Width shows it adding fuel to the cylinders, and the smoke out the back is confirmation. Now you just need some heat - like shorting out your glowplug relay.

Once you have fuel, then you just need compression and heat. Take one away and you have a no-start.

Your IPR is pushing hard without a lot of response from the HPOP. I think the Cody test is still in order.

axmrdr 04-11-2018 12:43 PM

Thank you Tugly.

BTW, I can't tell you how much I have learned from your signature links - so very helpful!

Some years ago I installed the really heavy duty glow plug relay mod that I saw here and it has worked flawlessly, so far. I am an electrician by trade so I can test out to see if the glow plug system is faulty. Everything else except electrical is what I have been struggling with ;-) I can check that system out tonight when I get home.

I am very sure that some of the system is working because of the voltage drop, from 12.4 to 11.2 when the key is first turned on, after a bit the voltage came back up most likely because the 'on' time had run out on the glow plug relay.(witnessed on a different test ) But I'll check to see how many plugs are getting power.

I plan on doing the cody test Saturday when I have a day off.

axmrdr 04-11-2018 09:49 PM

Took current reading of glow plug power cable, peaked around 50 amps.
At this point I think the cody test is going to show some leakage. Will see Saturday.

Tugly 04-12-2018 06:55 AM


Originally Posted by axmrdr (Post 17919715)
...I am very sure that some of the system is working because of the voltage drop, from 12.4 to 11.2 when the key is first turned on, after a bit the voltage came back up most likely because the 'on' time had run out on the glow plug relay.(witnessed on a different test ) But I'll check to see how many plugs are getting power....

Good job on "looking for sign"


Originally Posted by axmrdr (Post 17920684)
Took current reading of glow plug power cable, peaked around 50 amps....

Uh... you might want to ohm each plug (through the contacts in the VC harness), then ohm each GP cable to the relay post... and check all your connections while you're at it. I don't have the means to get a 50-amp read on a meter, but I use Ohms law to calculate it - and you aren't where I am. As the plugs age, they loose their resistance - and they are kaput at 2 ohms (48 amps on the system with Ohms law).

Now see there... your skills as an electronic technician, plus just a little diesel knowledge, will take you far with the 7.3L. This is where I have seen the world change so much - I used to keep my rigs up with wrenches, a timing light, and a dwell meter - now I have to use the multimeter, the laptop and OBDII adapter, and the USB O-scope. I'd be lost without my electronic career supporting my diesel (and boating) habit.

axmrdr 04-12-2018 08:47 AM

I got to admit it, I cheated. I borrowed the meter from work as my personal meter doesn't do DC current, just AC. I didn't have enough daylight to check each individual plug last night, and the wife is getting tired of me spending time under the hood instead of spending time with her - when I'm working outages our time (awake) is limited due to the long work hours, should be done with outage in a month, then she'll be glad I'm out of the house lol.

I didn't know they were bad at 2 ohms, thanks for that. What's a new plug ohm reading?

You're right about the change in requirements for keeping a rig running. It's a different world. I work on electrical devices all day and see how often they can fail, being in the field you've probably seen this too. While the newer technology is amazing at what it can do, the older technology is more serviceable 'on the spot'. Newer technology can be very difficult to troubleshoot as well due to the nature of electronic components, they can be very 'flaky'. I ride a 98 Harley because it has very little electronic components compared to the new ones. I've had for 17 years and just keep replacing parts as they fail or get unreliable. Mechanical components (and some electrical) can be fixed on the side of the road, electronic is another story.

I really don't like making vehicle payments, so keeping this ol' 7.3 going is pretty important to me. As a matter of fact, my plans are for this truck to last me until I start riding a rocking chair in the old folks home.

...."I'd be lost without my electronic career supporting my diesel (and boating) habit."

You have some good habits!

DogRidesInBack 04-12-2018 10:56 AM

While I have seen a lower low number written somewhere, glow plugs should be anywhere from 1/2 ohm to 2 ohms each.

So I would expect to see anywhere from 50 to 200 amps though the GPR.

Since is is unlikely that all 8 GPs are at 2 ohms (theoretically possible and in spec, but unlikely), 50 amps through the GPR warrants more detailed inspection (ohm out all 8 GPs individualy).

axmrdr 04-12-2018 12:01 PM

Gotcha. Thanks! The meter peaked at 50 amps and started dropping off to the 30s before I took the meter off. (just a few seconds) This would indicate that I do have some bad plugs since the resistance value is going up as they heat up. By the way they are wired to the contactor I'm assuming that they are either all 'on' or all 'off'.

I'm beginning to think that if I take off the valve covers to replace some orings that I'm just going to replace ALL of the orings and plugs as well. There's 270+k on this thing and it's probably overdue. I'm usually of a mindset that if it isn't broke don't fool with it unless it's obvious that a failure is eminent.

I've never had the covers off on a diesel so I'll be probably asking some dumb questions if I can't find a thread with them already answered. Any comments or tips are more than welcome.

DogRidesInBack 04-12-2018 01:22 PM


Originally Posted by axmrdr (Post 17921827)
By the way they are wired to the contactor I'm assuming that they are either all 'on' or all 'off'.

That is true for non-California trucks. California trucks have a Glow Plug Controller instead of a GPR which operates differently. And since you have a GPR (contactor), treat this info as trivia.

Sous 04-12-2018 01:27 PM

There is a lot of good information in the video below by the great Diesel Tech Ron.


Tugly 04-12-2018 02:12 PM


Originally Posted by axmrdr (Post 17921827)
...I've never had the covers off on a diesel so I'll be probably asking some dumb questions if I can't find a thread with them already answered. Any comments or tips are more than welcome.

Here's a question you probably wouldn't think to ask: "Can I run the engine with the valve covers off?" Surprisingly, the answer is yes. Oil doesn't shoot up when it's running - the oil shoots down because of the spouts. After I mess with injectors, I run the engine until warm, then I re-torque the injector hold-down bolts - and I get more spin out of the bolts. Warning - major suckage takes place while idling with all that air hardware off, so clear the paper towels and bungee the cat to the floor jack.

Hussler 04-12-2018 02:41 PM


Originally Posted by axmrdr (Post 17921827)
Gotcha. Thanks! The meter peaked at 50 amps and started dropping off to the 30s before I took the meter off. (just a few seconds) This would indicate that I do have some bad plugs since the resistance value is going up as they heat up. By the way they are wired to the contactor I'm assuming that they are either all 'on' or all 'off'.

Motor-Craft glow plugs are self regulating which means as they heat up the resistance goes up a bit and reduces current draw. Last glow plugs I installed measured about 0.8 ohms each. With ohms law initial current draw cold should be in the 120 Amp range assuming 12 volts and 0.8 ohms each. It's dirt simple to measure each glow plug at the valve cover with a multi-meter. This will give you an overall view how each glow plug is working. And yes, if you have the covers off just replace them all for piece of mind. With good batteries, good connections, good glow plugs, good GPR and good valve cover gaskets it's amazing how fast these truck will start up in cold weather.

Sous 04-12-2018 02:48 PM

Clearly this diagram only refers to one side of the engine, but as you can see the outer 4 pins (2 on each side) of the valve cover harness are the glow plug connections.

Pins A, B, H and J in the diagram below are for the glow plugs on that side of the engine. You should be able to ground the black contact on the multi-meter (MM) and use the red contact to touch the pins on the valve cover harness and check for resistance on each of the glow plugs without removing the valve covers. Each plug should be below 2.0 and if they are not, they are bad. If you decide to remove the valve covers, then simply remove the connector from the top of each glow plug and touch the red contact to the top of the now exposed glow plug.

Same readings should be observed from the MM.

https://cimg0.ibsrv.net/gimg/www.for...eccf66e4f0.gif

axmrdr 04-13-2018 06:03 PM

Thanks for all of the help, great information!

I ohmed out the passenger side plugs and found them to read good at .8 ohms. I will ohm out the other side this weekend. (Ran out of time) I think that I'm still going to replace all of them, cheap insurance while the covers are off. Funny thing is that there was 6 ohms from the glow plug terminal to the negative terminal of the battery but .8 to the housing of the alternator. Sounds like some of the ground connections on the engine need to be cleaned up. Will take care of this too.

DogRidesInBack 04-13-2018 07:30 PM

Assuming the other 4 are also 0.8 ohms each, the entire set connected to and read from the GPR should be 0.1 ohms. And if they are all 0.8 ohms, the cheapskate in me says to leave them alone, they are fine.

Assuming a nominal 12V, the set should draw 120 amps.

That ground difference definitely needs to be fixed, it will also affect battery charge from the alternator. And 6 ohms of resistance will not allow the glow plugs to reach full heat. I also question the 6 ohms, check that again between the alternator body and the battery negative terminal. 6 ohms difference there would cause all sorts of problems. Check it to both batteries, maybe one (the one you checked) battery has a bad connection.

I also question it since you read 50 amps in the glow plug circuit, and 6 ohms resistance in the ground would limit the set to 2 amps.

axmrdr 04-13-2018 08:52 PM

Well the low voltage and tiny current that a meter uses to get an ohmic reading is nothing compared to the voltage and current of a dual battery setup pushing current to fire the glow plugs and a engine starter so that reading I took earlier is misleading. Never the less I am going to check out the ground connections. You're right, it could cause other problems.

I suppose reading the GP again with the VC off would be a good idea before I make a final decision. ;-)

"Check it to both batteries, maybe one (the one you checked) battery has a bad connection. "

You have a good point. I didn't try both batteries, will do it in the morning.

Tugly 04-14-2018 07:31 AM

Two years ago, I ohmed out the grounds to each battery. The passenger side battery was fine - not so much with the driver side. I have since been on a "clean the grounds" binge, and I completely replaced the positive battery cable assembly and starter. After 19 years, that was some good medicine.

I would ohm the glow plugs through the valve cover gasket connections. The Under Valve Cover Harness (UVCH) is one of the most commonly replaced parts on the 7.3L, ask any Powerstroke or Navistar shop.

axmrdr 04-14-2018 08:21 PM

OK, cleaned grounds. Found number 5 glow plug with no reading to ground (taken from UVCH plug as advised). All others read 1.0 ohm to ground. Hooked up ammeter to brown wire and energized - 69 amps, yellow wire - 75 amps. The math doesn't quite work out but not going to worry about that,this tells me that 7 of my glow plugs are working. Not the cause for not starting. Either the harness is bad or a glow plug is.

However when I tried to ohm out the coils of the injectors the readings on the passenger side were pretty consistent but on the driver side readings were all over the place. Could indicate a bad harness or injectors.

I tried to do the cody test but it seems that you need to have the covers off to be able to tell anything. I had more chores to do than 1 man can get done in one day so I didn't have time to get the VC off.) I couldn't hear any leaks but without the VC off I probably won't.

When I released the air from the passenger side it puked oil back out as I have read the warnings posted here, but no oil puked out on the driver side. Is this significant in any way?

Since the harnesses are prone to go bad I'll be ordering a pair.

Tugly 04-15-2018 06:53 AM


Originally Posted by axmrdr (Post 17926508)
...when I tried to ohm out the coils of the injectors the readings on the passenger side were pretty consistent but on the driver side readings were all over the place...

There's your no-start.


Originally Posted by axmrdr (Post 17926508)
...When I released the air from the passenger side it puked oil back out as I have read the warnings posted here, but no oil puked out on the driver side. Is this significant in any way?

You're going to find out as you replace the UVCH on that side... when you repeat the Cody test with the driver side valve cover off - that sounds hinky. I'd order a full set of O-rings to go with the UVCH anyway... so you only have to wait just one dog year for parts instead of two.

axmrdr 04-15-2018 12:33 PM


Originally Posted by Tugly (Post 17927005)
There's your no-start.



...... I'd order a full set of O-rings to go with the UVCH anyway... so you only have to wait just one dog year for parts instead of two.

Already have received a full set (8) of orings, a tool for the HPOP lines and a 4K psi gauge and hose. Just ordered 8 glow plugs, 2 UVCH, 2 valve cover gaskets and an IPR pigtail. I don't want to go into this critter again anytime soon. It's still less than 1 truck payment.

I am going to rig the new IPR pigtail up so I can energize the IPR without having to rely on the IPC to power it up.(for any future diagnostic purposes - testing HPOP)

Don't know when I'll get 2 days off to devote some time to replace all of this. Retirement can't get here soon enough. When I find out what the problem is I'll be sure to post it.
I'm sure I'll have more questions before this is all done. Thanks

Bonanza35 04-15-2018 01:41 PM

Good luck. Will wait for your post.

Jaime74656 04-15-2018 02:50 PM


Originally Posted by axmrdr (Post 17916888)
Oil level is good, just changed oil - after truck died. I had the truck towed back to my driveway, shop is full of other projects so I'm relegated to working in the driveway for now..

I'll remove the chip as well, 20 minute job I can do today after work. Since you're here ;-) and you're the AE expert, what option in the drop down window do I select to get AE to see the high fuel pressure, I swore I have done it before but it's been a while since I used AE. I'm reading your AE class thread in between jobs at work but retaining everything that I'm reading is a bit overwhelming.

Presently working 12 hours days but as soon as I can I'll check wiring and do a Cody test. (I'll read up on that).


AE will not read FP on these trucks, same for EGT, if you need fuel pressure, either a test gauge at the fuel bowl or a more permanent hard gauge (pillar pod or similar) will be required, every thing else can be found with AE or Torque Pro (or The free edition of TP)

Tugly 04-16-2018 08:51 AM


Originally Posted by axmrdr (Post 17927533)
...I am going to rig the new IPR pigtail up so I can energize the IPR without having to rely on the IPC to power it up.(for any future diagnostic purposes - testing HPOP)....

I wouldn't. But if you do, just make damn sure the signal to the IPR is not connected to the PCM when you test it this way. The IPR is modulated, and the engineers made sure it didn't reach 100% duty cycle like you're doing. If you really want to troubleshoot the IPR... add a connector that allows you to check it with a meter while cranking, but seals from the environment any other time.

axmrdr 04-16-2018 12:34 PM

Until I read your response I was considering this for any future troubleshooting issues. ;-)

What voltage is correct? (voltage) without tuner and with? I can definitely add a way to test the voltage being applied to the IPR.

My initial thought was to throw 12 volts at it to check psi output of hpop momentarily (few seconds), is this a mistake? Wouldn't this eliminate the HPOP and IPR issues during troubleshooting?

By blocking one side at a time and checking pressure (using ICP and PCM this time) on each side for oring leaks? Please tell me if my thought process is wrong.

I see that riffraff has plugs for the quick connects on the pump, I'd like to make it so my pressure line had a quick connect also so I could more easily test each side and have ability to test dead head pressure as well if needed. Do you know where those fittings to do this can be purchased reasonably? I'm terrible with plumbing terminology so please make it simple. This is what I have .

The way I see it any money spent on diagnostic tools is in reality saving me time and expense later on.

hydro man 17 04-16-2018 02:14 PM

There is a company called hose & fittings. They seem to have most anything in that category you could think of. Prices seem to be in line but I have only purchased a few thing from them.


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