2000 Ford E350 - 7.3L Int Running Problem

[liljoe]

I have a 2000 e350, 7.3 powerstroke, several times it has been towed in for poor running not pulling.

Each time it has came in, it has ran great, only code in PCM was for IDM code, ran contribution test and had no codes, no codes in buzz test. One time when I was pulling it off the wrecker it was skipping, hooked to it and got codes for cylinders 2,4,6,&8 during buzz test, re-did buzz test right after wards and it passed with no codes. At that time the customer ( ambulance company ) opted to replace IDM and valve cover gasket/under cover harness. Sent truck out, came back about a week later on the wrecker, unloaded it, PCM had code for IDM having codes, IDM had no codes, passed both tests plus KOER test also.

At this time I decided to keep truck and use it for my car. I had ran it for a total of about 35 hours idle time and 185 miles of off and on driving simmulating different conditions of idling, hot soaking, driving, cold starts, hot re-starts, easy driving, hard driving, donuts in the parking lot across the street, every thing I could think of to duplicate the problem with no luck till last night on my way home. I had ran the truck a couple hours before go home time and then drove 7 miles, had to climb a hill of about 15%grade and 1.5 miles, at top was a stop sign. Left from stop sign kinda hard and let off about 100 yards later to descend the hill, at that time the SEL came on and I could tell it sounded different. I accelerated to see what it felt like and it had no power/skipped. Got to the bottom of the hill (2 miles) and pulled over to the side and hooked lap top to truck. Had PCM code for IDM codes. Went to cont test and as soon as the test finished running and it was displaying the codes, P0266,272,278,284, the truck smoothed out. Reran test right then and it passed.

Left from that place and had a 2 mile hill of 15-20% grade and when I topped it and let off, it did it again, got to the bottom and pulled over, shut off truck, restarted. Ran perfect, passed both tests. Got to work this morning and figgured I would be able to make it act up my doing the famous wiggle test. I have removed the basic things needed to gain access to the harness and have tugged, pulled, wiggled, and shook the harness for over two hours trying to find an open or short in the harness to no avail. Has any one got any insight that will lead me into happyness?

Thanks, Liljoe

[brianp87]

Do you hear any diff when you run the buzz test? Ive never seen it but heard to check oil drain on injector for differences between injector. Id lean towards injectors or low fuel pressure.

[liljoe]

Buzz sounded nice and even, when running the truck and looking at data, the highest cylinder on the scanner is varrying between .5 and .8, the rest are staying at zero. Will one injector be able to cause it to have cont codes for all cylinders on that bank? I have never seen that my self. The thing will go back to running fine with just a key cycle or running a self test with scanner. At first I figured I was chasing something that when it failed, it would stay failed for long enough to see what was going on. Wish I would of had the scope on the power wire for that bank when this happened . I am thinking that either the power feed wire for that side is shorting/opening or it is having some sort of module issue, But the problem is sooooo intermintent that I am having a hard time dupliacting it. I have made the same trip twice today that it acted p on yesterday and have not had any problems, had made that same trip several times before yesterday also.....

[brianp87]

So the 4 showing faults are on the lh side. Its tough to say wish it would do it long enough to tell. youd think injectors wouldnt come and go but then again wtf do I really know. Id think about pulling valve cover and checking the oil thing they talk about. Does the scanner show a fuel pressure pid?

[liljoe]

No pid for fuel pressure, ran with cover off and the oil comming out of each injector looked the same. Have no problems running except when it decides to act up, then it only acts up till the key is cycled or self test is ran. Then truck runs like it should, I have wiggled,yanked,pulled,shook, and cussed this thing till I am REAL glad it is time to go home. Gonna hook scope on the wire that feeds the injectors for that side and hope it acts up again. I do want to give it back till I find the root of the problem that is happening. It happens so seldom that it is hard to tell when it will do it again,,, and when it does, the problem seems to be happening then going away very fast but the IDM is shutting down that side till it goes through a cycle.

[brianp87]

I agree its odd. Its also odd that it only affects the one bank. hmm

[steven kiser]

One sticking injector will effect the pressure of the rest on that bank. Any time we have to open one up to replace any injector issue on a single head all get replaced or if customer balks at it we require a signatore on a disclaimer form. I've seen the oil tube leaking on occasion and i will run it with an oil pressure guage on the engine as well as the high pressure pump.


We were running into wierd intermiatant issues with these and switched to rotella motor oil and it seems to have subsided. As we all know these can start acting up because of a intermitany oil pressure loss. Usually when at operating temp and we've found it isn't an issue of strain but angle. We had one in the shop and we couldn't or wouldn`t take it out because of torrential rain so we drove the front up onto the alignment rack and put a brake pedal lock ron on the accelerator and let it run. After a while we got it to start to scatter and it was an oil pressure issue, there was debris in the crank case so we flushed the boogers out of it, blew the pressure sensor port clean, filled it with rotella and haven't had the issue with it since.

[liljoe]

Strange thing is, when it does it, the truck will run on the four cylinders on bank one and bank two does not. As soon as you either cycle the key one time or complete a self test, it will reset and run great. I am still thinking it has to be an electrical issue that the IDM is seeing for a split second, then it seems to go into a fail safe mode that cuts off the signal to bank two.?...?? Fixing to rig up an adapter harness so I can run the truck and create an open in which ever of the five wires ( one high voltage supply and four grounds from the IDM ) I decide to try. I will see if the IDM goes into fail safe when it sees open on high voltage supply, and how it acts when each injector is open circuited. Will let yall know what the outcome of this testing is.

[steven kiser]

Fail safe or limp will balance out by shutting down cylinders but i don't think it is all on one bank.

[liljoe]

UPDATE.

Made a jumper harness out of pigtail that came in a dorman valve cover gasket kit that I had from another truck and if I create an open in the wire feeding the injectors power (center wire on valve cover plug) the IDM will power down that side, if I create an open between any injector and IDM, it just sets code, two injectors sets code, three or four injectors and it powers down that side. All this was just expermenting I did for personal knowledge of operational theory for the IDM. I have driven this thing another 280something miles since the other day and still have not gotten it to act up again. I have spent at least three hours wiggling, pulling, bending, and pushing on the harness with out causing any glitches at all ( watching with scope on feed wire and one injector signal wire ). I am leaning towards either a very intermentint break in the feed wire or a connection issue some where. Looks like I will be giving this one back and tell them to run it as a BLS truck and not ALS and hope the problem will show up again......

P.S. Was told by my boss that there is no such thing as an intermintent problem, only problems that happen under a precise set of conditions.... Wish I could duplicate those conditions......

[Tim Martin]

I have failed in following this thread. My fault.

First of all, the codes, PO266, 272, 278, 284 are not electrical codes so to pursue electrical issues is wasted time in my opinion. They are mechanical codes that affect the ability of a cylinder to make a full contribution to engine performance. Things like valve springs, rings, fuel pressure, oil pressure, or the injector itself can cause these codes. The one thing I am looking at is that these codes are all identifying cylinders on the left bank (drivers side). I think this idea has already been mentioned in a previous post. Basically speaking, there is only two things that can affect all 4 cylinders on the same head at the same time: (1) fuel pressure and availability, and (2) Oil Pressure and availability. And, whatever is at fault has to be a variable, meaning it can be intermittant. Only fuel and oil have that ability. So, if I was diagnosing this one, I would start by hooking up a fuel pressure gauge on the left cylinder head and having it so that I can observe the gauge while I am driving the van. The test port for the left head is on the rear facing the turbocharger.I would also have my scanner hooked and be observing ICP and IPR pids. These figures should clue you in to where the issue is. Having said that. If think there is a check valve threaded on each head where the fuel line is connected to. This check valve also has a screen in it to keep fuel line oring debris out of the injectors. I have seen these screens get restricted enough to cause an issue. Perhaps this is a problem on this one. Just a thought. Another thought was that if IPR percentage goes higher during the times of poor performance, that indicates a high pressure oil leak somewhere in the system, most likely in the left head.

What is ICP and IPR pids during idle and at say cruising speed or when pulling a hill? Those numbers could help steer this diagnosis in the proper direction. I ain't trying to sound like a know it all but we have seen alot of these 7.3's with many differing situations and these are a few thoughts I had.

[liljoe]

7.3 wot uphill.JPG (27.26 KiB) Viewed 5525 times

7.3 at idle.JPG (31.34 KiB) Viewed 5525 times

Those codes were retrieved with cylinder cont test on scanner, as soon as test finished the truck smoothed out and shut key off did KOEO and injector buzz test, both passed, started back up and did cont test and it passed. Left that spot and went a couple miles up hill and at the top it did again. Coasted to bottom and found a place to pull over. All I did was cycle the key off and right back to start, truck started and ran fine. Did a couple screen shots of idle and wot pressures/%. The sensor is reading correctly ( I test the sensor with a manual gauge set up ) The IPC sensor is on driver side, so I know its reading is gonna be accurate for that bank. If I unhook an injector and run cont test, all I get are cont codes for which ever cylinder I unhook. If I run buzz test or KOEO, I get electrical codes for affected cylinder. My thinking after running with different combonations of unhooked injectors and power supply wire is that the cont test does not look at anything except for the engines smooth running ability, and KOEO and buzz tests will check electrically.

[brianp87]

What did you ever find on this beast

[liljoe]

OK, I drove this thing for another week, puting over 300 more miles on it before it finally acted up again. When it did, the power for driver bank went down to zero, I ohmed the injectors at that moment and found #4 to be way lower then the other three on that bank. Fuel pressure and IPC both stayed nice and steady when it messed up, so I ruled them out at that point. I unhooked #4 and it started and ran as good as expected on seven cylinders. I was in the middle of nowhere (5 miles from cell reception) so I sure was glad to get it running. Got it to the shop the next morning and put 4 injectors in that bank and, as I always do when I put an injector in one of these, I replaced the fuel filter and cleaned the housing and the line going to that bank as well as the passage in the head using carb spray and compressed air. Gave it back to them and it has already came back for a 3000k service and had no more problems. Sorry it took me so long to post details on the outcome of this, but I wanted to make sure it stayed gone before I posted anything, then it slipped my mind after that....

[brianp87]

I hate these type of issues. I had a 6.0 with a miss and it would never set a code. It passed the baloon test, buzz test and ohm test. Finally we drove it enough for it to get fuel in the oil then I knew what was wrong. On a cyl contribution test it showed a weak cylinder so I bit and that injector was bad. Sealed the rest. Glad you figured it out.

[liljoe]

Funny thing is, even after this much time, i still worry over it messing up again and it leaving a sick person stranded in the back.. every time it goes by with sirens on i worry, is it gonna quit this time? But so far, so good. Gonna try to get auth to replace the other four in the next 8 to 10 thousand miles....

[Tim Martin]

OK, I drove this thing for another week, puting over 300 more miles on it before it finally acted up again. When it did, the power for driver bank went down to zero, I ohmed the injectors at that moment and found #4 to be way lower then the other three on that bank. Fuel pressure and IPC both stayed nice and steady when it messed up, so I ruled them out at that point. I unhooked #4 and it started and ran as good as expected on seven cylinders. I was in the middle of nowhere (5 miles from cell reception) so I sure was glad to get it running. Got it to the shop the next morning and put 4 injectors in that bank and, as I always do when I put an injector in one of these, I replaced the fuel filter and cleaned the housing and the line going to that bank as well as the passage in the head using carb spray and compressed air. Gave it back to them and it has already came back for a 3000k service and had no more problems. Sorry it took me so long to post details on the outcome of this, but I wanted to make sure it stayed gone before I posted anything, then it slipped my mind after that....

Thanks for posting what you did.

The injector circuit on the 7.3L is designed that if an injector is drawing too much amperage, the computer, in this case, the fuel injector driver module, shuts down that bank to protect the other injectors. Admittedly, this type of system can be difficult to diagnose however with experience it becomes easier. I am not at all surprised to see that this is what you did. However to tell how to diagnose it is not easy.

[steven kiser]

As a rule when a whole bank shuts down it has to do with the driver module. Many of the issues are from bad connections. The plastic cleat that holds the plug into the module breaks and the plug backs out. I can't remember seeing one without wire ties holding it together. It kind of makes sense that the module is overheating and shutting down one bank. If you do find a ban plug retainer the module is more than likely junk because a loose connection creates heat and heat isn't a circuit boards friend.