Hey guys haven't been as active on here as I would have liked to be lately but hopefully that will change soon. But now the reason for this post is lately I've been having some trouble with my truck. My truck is an 02 F250 7.3 with 280,000+ miles on it, so I wouldn't be surprised if I might have a number of things going wrong. It runs pretty good, but is still far from 100%, at least up to my standards. So the problem has been going on for the last two or three weeks and got worse today, and there were a few things leading up to it as well. I'll start off with the first thing that happened that I think might be related. It was about 6 months ago, my buddy and I were putting my new headlights in. It was parked in his garage and we backed it out a little bit to try and adjust them. It was sitting there idling for a minute or two and just shut off or almost stalled out. Tried to restart it and it wouldn't start, tried multiple times to no avail. It acted similar to when I had glow plug troubles when I first got the truck, it would just crank and crank, but never actually kick over and start, along with putting white smoke out the exhaust. Ended up waiting about a half hour and then the truck fired right up with no problems after that, so I didn't think much of it.


Then fast forward to last week to when something similar happened. Started it up after sitting for a few days, started right up, idled for a few seconds and then just shut off. Started it back up ran for a second and died again. Tried a third time with the same result. Fourth time fired right up again and stayed running, let it run for a few minutes and was fine. Also along with this, there was a bad squeaking coming from the front of the truck, like what a belt would sound like. I have recently replaced the belt because it was squeaking and actually got chewed up and almost shredded completely apart. So not sure why it is squeaking again, but not sure if this could be related or not. Then took it back to my dorm room to get my stuff, and then made it the hour or so drive home from school, without issue. Even went to a few stores before I went home, and shut the truck off and started it back up multiple times, again with no issues. When I drove back earlier this week it was fine until I got there and put it in park. It idled for few seconds and then cut out for a second, but then idled back up and continued to run fine. It has done that a few times as well. So it will do it on a cold start or after already fully warmed up.


Then it got worse today. Again had trouble starting it cold, same as what I explained early. Except second time cranking it wouldn't start at all, then on the third crank it started up and stayed running. But on the drive home is when it got worse. About 5 or 10 minutes into my drive, was just cruising doing at about 45 or 50, and truck just shut off, died/stalled out. It cut out and shut off for a second or two and then started itself back up and continued on like nothing happened. It scared the crap out of me the first time it happened, I was waiting for something like that to happen, but still wasn't quite ready for it, haha. The truck acted just like it would before you start it, with the key on, dash lights worked and the radio still worked. It did this 4 more times in similar ways, would die and then start back up, at various speeds and at roughly 5 or so minute intervals. I decided to just keep going as long as the truck would start and stay running, hoping to make it home. It did it a fifth time and this time the truck completely shut off and wouldn't restart itself. It was hard to see, as I was watching a few different things at one time, but I think it tried to restart, I noticed the tach bounce between 200-400 RPMS and then die. So I had to pull over and then restart it, fired up and drove fine. That was about half way home, and I made it the rest of the way home without any more problems thankfully.


So obviously I'm wondering what would be causing the truck to do this? I've done some reading and have a couple ideas, but not really for sure on anything. I was thinking maybe the CPS, I think it can cause a no start issue. Could ICP or the ICP sensor have something to do with it? I was also thinking maybe something fuel related, such as fuel pressure or a bad fuel pump. Any of those sound to be on the right track?


I have the torque pro app, but not exactly sure how to use it yet, and also just got access to my Uncle's Snap-on scanner, so I ran some tests and pulled some codes. And any advice on how to more utilize these tools in diagnostics would be greatly appreciated as well. I did get a few codes, but I'm not exactly sure how they might be related.


The codes are pulled are:
P0470 Exhaust Pressure Sensor Circuit Fault. Just cleaned that out as well as the tube about a year ago, but I guess could be clogged again or has gone bad.


P1274 Cylinder 4 (E) High to Low Side Open. Did some reading and figured out that this could be UVCH related. At the same time, about a year ago, did new injector O-rings as well as all new Motorcraft UVCH's, so can't imagine that one is bad. Or that one could be loose, I would have guessed it would have happened more when I first did them, not a year later, but who knows.


Also pulled P1876 T-Case 2wd Solenoid Circuit Fault. Not sure if this is related at all, but also not sure what it means either. I read that it could be ESOF system related, which I do have, but I have manual lockout hubs, so maybe that's why it throws the code.


Also a few things that may or may not be related, but I think worth noting. Ever since I've had the truck the check engine light will pop on and off sometimes. It will do it on a cold start or, when I first start driving and its not fully warmed up yet. It does it most when the engine is still cold, and it almost never comes on once the truck is fully warmed up, but has came on and off more frequently lately. When driving, it will only stay on for a few seconds and more often when I'm lugging the engine or at lower rpms, and will commonly shut off if I let off the throttle. I don't think it really comes on at higher rpms. I also have a slight oil leak in the valley of the engine, seems to maybe be coming from the front of the motor. Nothing too serious, leaves a small puddle where I park, loses enough to be at the add mark, a little before an oil change. Changed the oil about 1500 miles ago and have been able to notice a slight drop in oil level. I was planning on starting separate threads for these problems, but figured I'd mention them in case they might help at all. Also I have changed the fuel filter in the last 500 miles.


I think that's about it. Sorry for the long post, I always try to keep it short, but that never happens with me, haha. I just like to give as much info as possible, hope I made everything clear. Thanks for any help in advance.

 

Bump- any ideas guys?


A little more info. I have noticed a little bit of a rough idle sometimes, like the truck might have a bit of a shake to it. Nothing major, and could just be the truck idling, it is a diesel, its just enough to barely notice it sometimes. I figured this could be maybe point more towards the CPS.


Another thing is for the last few months I've had some pretty poor fuel mileage. Its been in the 11-12 range. Now I don't drive the truck too much, on average 2-3 times a week at maybe a 100 miles or so. And its not city miles but not full highway either, there like country roads, with a good amount of them in the 55-60 mph range. So I know its not the best circumstance for mileage, but I still think I should be getting better than that.


Also did some more reading on the P04070 code with the Exhaust back pressure sensor, and some people reported similar issues to mine. Could a plugged tube or bad sensor really cause the truck to stall like that? I would have never expected that, but I'm no expert. It would be nice if it were that simple.


Other than that, the truck runs fine. Always have plenty of power and boost, and really not any other major issues that I've noticed. Hopefully will get a chance to look more into it today or tomorrow.

 

Well I did not want to read the books you posted so.

1. Camshaft position sensor. Well known for random dying.

2. IPR nut loose or missing. Tin but on back side of HPOP

I have had both happen to me.

 

Thanks for your response Jason. And yeah sorry for the books, I've never been good at explaining myself quickly, especially when having to type or text, would much rather talk. And I just like to give as much info as possible and be as descriptive as possible, so you know exactly what is going on and to hopefully avoid an excess of questions that I could have easily just answered by including them in the first post like did. I stated just about everything I could say about what was going on and what I was thinking. But you like you said it ends up pretty long and most people don't want to read it. So I'll try to give a very basic description of what is going.


The truck started out dying on start up, and took a few starts to get it to stay running.


Then yesterday it would died 5 times while driving. Would essentially stall out and then start itself back up. Fifth time had to pull over and start the truck back up, then made it home without issue after that.


Got home pulled some codes off of my Uncles Snap-on scanner. Got these codes: P0470 Exhaust Pressure Sensor Circuit Fault.

P1274 Cylinder 4 (E) High to Low Side Open.

P1876 T-Case 2wd Solenoid Circuit Fault.


I was thinking it could be the CPS or maybe fuel pressure related or a possible a bad fuel pump. Or maybe something with the ICP Sensor. I do have an oil leak, and have been getting some pretty poor MPG lately. I understand that the first code most likely means that the EBPS could be bad or clogged, but wasn't sure if that could cause the stalling or not. Anything else or questions, I've probably already stated in one of my first two posts, all that is about everything I could say anyways. Thanks again.

 

NA11 DIAGNOSTIC TROUBLE CODES (DTCs) P1271-P1278
From the Factory Troubleshooting Guide Book


DTCs P1271-P1278 indicate a low side-to-high side open in the circuit between the IDM and the injector. The following table lists the circuits to inspect while performing these pinpoint tests, based on the DTC retrieved during the KOEO On-Demand or Injector Electrical Self Tests.

Note: If all of the DTCs associated with an entire bank are retrieved, the high side circuit is most likely open.

Disconnect injector valve cover connector.
Install Glow Plug Injector Adapter 014-00935 or equivalent to valve cover gasket.

Measure resistance between the high side and low side on the injector. Refer to injector illustration at beginning of this pinpoint test for proper pin location.

 

Did u put HID lights in? Aftermarket CPS and ICP have been known to have poor shielding and act up with those at times.

 

It sounds like a bad electrical connection if it dies and starts itself. Have u done the 50 cent mod or replaced your UVHC gasket. They are prone to coming loose.
I still wouldn't rule out the CPS or Tin but on the IPR.
You can always unplug the ICP sensor and see if it runs better. When u unplug it the computer defaults to a certain pressure.

 

Hey guys sorry for the late update, had a long and busy week last week. But so far the truck is running good as of now, I'll get more into it below. Also, sorry tried to keep it short, but it didn't exactly happen, lol. You could probably fast forward to the last longer paragraph if you don't want to read it all. Oh yeah just did the preview post thing, its really long again, sorry guys, definitely fast forward to where I said to, if you don't want to read, that's where we figure it out.


Thanks for the info Tom! I will definitely have to look more into that when I get a chance, because I was still getting that code, the last time I checked.



Yes I did actually. Didn't think about it at the time, but my lights were not on at any of the times that it stalled, or that I had problems, so that shouldn't have been a factor, correct? I know that the HID's can affect some electrical things, but I haven't noticed any major issues with mine. Mine do mess with things a little bit, when I first turn on the lights or if I turn on the high beams, my speedometer will drop quickly and my ABS light will pop on, but this is only for a second or two, and after that all is fine. Other than that I haven't noticed any adverse effects from them, that I know of.



Yeah that's what we were thinking on the bad electrical connection. I put in brand new Motorcraft UVCH's about a year ago, but did not do the gaskets, but they looked good at the time.


So I'll get into what we did to fix it now. So last Saturday I went to my Uncles house, he's got all the tools, to look into it some more. I had a little trouble starting it but it made the drive over there fine, only a five minute drive. So we let it run a little bit and did some tests with the scanner, and checked for codes. All was good except for we were still getting the P0470 and P1274 codes, so we figured we'd clean the EBP sensor and the tube going to it, since it was quick and easy. We figured it wouldn't change anything, but was worth a shot. So we pulled it out and cleaned it, didn't look too bad, and then put it back in. After this we stopped for dinner and just let the truck sit. My cousin had a friend over and his Dad came to pick and we ended up BS'ing with him for like and hour and a half, he's got a 7.3 as well. We lost at least a good two hours or so to all that. So the truck was sitting for a good three or four hours, so it was pretty cold.


Started it up and it started fine, we let it run for a few minutes. My Uncle put a small light bar on his truck, so we were checking that out, while my truck was running. As we were doing that, we heard my trucks idle drop, like it cut out for a second and then kept running. So we walked over to my truck and talked for another minute or two, then as we were standing there the truck just shut off. And my Uncle was like oh, that's the problem, lol.


So we started it back up, started fine, let it run for a few minutes and it did it again. It did it a few more times, probably every 5-10 minutes or so. Then it just got progressively worth over the course of probably 2 hours or so. It started out as it would cut out every two to three minutes, or just completely shut off. Every so often it just wouldn't start at all, we knew when it would start and when it wouldn't. When it wouldn't start: with the key on the glow plugs pigtail and the check engine light, as well as a few other dash lights would stay on and not shut off. When it would start: everything would shut off and act like normal. Then if it started, it would just eventually completely shut off, and by shut off its not like it miss and skip and run rough and then just die, it was literally like someone just turned the key and shut it off. Then it got to where if it started it would just shut off shortly after it started. And then it got to the point where it just wouldn't start at all, and actually wouldn't even communicate with the scanner. The scanner said no connection detected, it couldn't even communicate with the PCM.


So after that we were really stumped, and were all just looking on our phones trying to find different things to try. We tried unplugging the ICP sensor, with no change. Tried unhooking the batteries for a while to try and reset everything, no change. I eventually read something where one guy said he was having similar issues, and it ended up being a bad connection with his chip. So I figured why not give it a shot, unplugged my chip from the PCM, truck started right up with no issues. Plugged it back in, again it wouldn't start and same problems as before. Unplugged it again and all was well, truck started right up and ran fine. So all that just for a bad connection or problem with the chip! So now it is just unplugged and zip tied under my dash. And its been fine since then, drove it around a lot last Sunday with no issues, made it to school and back this week without a problem. So I guess I'll have to take out the PCM and make sure the chip has a good connection and everything. The chip was installed by a previous owner, and whoever did it just cut a hole in the cover of the PCM so it could be plugged in and unplugged easily, I guess. When my Dad and I first went to look at the truck, it was originally unplugged, and my Dad just plugged it in that day. So the whole time I've had the truck, about a year and a half, that's the only way its been actually plugged into the PCM. I'm honestly surprised I've made it this long without issue.


So a few questions that I still have, could the chip having a bad connection, actually cause the stalling and no start issues? Just did some reading and it seems like it can, but want to be sure, and make sure that I don't have any other problems.


Also the check engine light still pops on and off intermittently as I drive, mostly when the engine is cold, or lugging, but still almost seems to a random occurrence sometimes. Will probably have to start a different thread for this, but figured I'd mention it.


Also after scanning for codes after driving around last Sunday, I'm still getting the P0470 code, does that mean that maybe the EBP sensor could just be bad, as we've already cleaned everything out? And the P1274 Cylinder 4 (E) High to Low side open code, as well as a C1284 Oil Pressure Switch Fault. Not sure what those mean exactly.


Thanks for everyone who posted some ideas and tried to help, I appreciate it!

 

I appreciate having the whole story, so thanks for taking the time. More detail helps diagnosis.

So yeah, the bad chip connection can cause all that grief. Congrats on solving the big problem! Pull the PCM and have a look at the connection, might need a bit more cleaning, but also could be cleaned too much and the chip will not grip. Need to get off the silicon that was on there, but not too much of the solder. Post a pic of it if in doubt.

Torque can read barometric pressure and the EBP. KOEO they should show about the same pressure, within .5 psi of atmospheric. KOER the EBP should vary with load.

 

happened to me 7.3 pwrstroke, it was my oil pump.