7.3 powerstroke experts
 

My 2001 powerstroke 7.3(60,000miles) turns over but won't fire. Hpop is working, has fuel , but no power to the injectors.(i think) replace the cps and checked the obvious stuff. I brought it in and it was throwing IDM codes ,it was reflashed and ran great like it always has. Let it sit for a couple of days and dead again. I put a new IDM from swamps and still no start. Could it be my computer is dead?? Before it gets towed in again , any suggestions from anyone? Something simple I have missed? thanks jay.

Have you checked your oil level?

you can check your injector power at the valvecover harness plug.. should be one in the center on yours... the older had 2 How do you know your hpop is working? hard to diagnose alot without some sort of scan tool.. even then most wont do what ids factory ford scan tool can do ..

i cant rember if its same on 99 and newer but on 97 down it is on drivers wheel well buy idm check your underhood fuse box for fuse 22 blown.. if thats case you prolly have melted wiring under fuel filter housing or short to ground fuel heater ... if its blown put another in see what happens.. it will blow again start it up in driveway dont drive it..

if that dont pan out lemme know.. i just swapped my 93 nonturbo auto truck over to a 97 powerstroke stick drivetrain front to back swaped wiring from head to tail lights... and worked on a bunch of em

My 7.3 stalled at a stop sign, had it towed, after throwing everything at it, IDM,PCM etc ect, problem still there... Took to another shop, 30minutes later they called and said to come get it, very low on oil, problem gone, now my friggin od light is flashing!!!!!

thats not good.... :lolhit:

Not good at all ! After reading the power stroke forum about flashing OD light, I'm thinking nightmare part 2 begins! All I can do is laugh and deal with it!!!

Had the simmilar thing happen on my 99... The fuel bowl heater was shorted causing the PCM fuse to blow. The fuse is located under the dash, don't remember which one it is. Are you able to communicate with scan tool? Does your wait to start light work? Neither of these worked on my truck and they are red flags for the PCM fuse.

Not to hi jack northern's thread, but I fought a flashing OD light to wits end last summer... It kept throwing an OSS sensor code. Replace sensor, no change. Under heavy load at low speed (i.e. boat ramp) the truck would buck and stall and shift into OD sometimes locking the converter and stalling.

Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.

Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.

Major PITA!

Edit: whenever it would have one of it's full stall episodes it would throw a whole slew of IDM, low voltage, cmp, etc. codes. They were all erroneous, and only happened after a full stall. The ony consistent code was OSS.

fixx
 

that was the first thought,,offshore sometimes they short so bad it leaks fuel out the filter housing,,like mentioned if the fues is blown you can un plug it to get it to run but it may take a long crank to start it..if that not it they are known for crankshaft sensore and the high fuel pressure switch which is i think in the cylinder head..beed a whyle since i had a 7.3 with any problems..try unplugging the idm and leave it unplugged,,have someone crank it and plug it back in whyle cranking,,may start..

[QUOTE=RT930turbo;3885464]Not to hi jack northern's thread, but I fought a flashing OD light to wits end last summer... It kept throwing an OSS sensor code. Replace sensor, no change. Under heavy load at low speed (i.e. boat ramp) the truck would buck and stall and shift into OD sometimes locking the converter and stalling.

Long story short, my alternator had a leaky rectifier diode that was back feeding trace AC current to the truck at the right frequency to 'mimic' speed sensor signals. As the revs hit 1100 or so, the signal was that VSS and OSS were way over 100 mph causing it to go into OD and activate the speed limiter fuel cut.

Once the truck was actually moving the sensor output was strong enough to overcome the trace current and the truck drove normal.

Major PITA!


The OD light is not flashing in my driveway at idle, when it was flashing it drove normal for the most part, but would waite to shift a bit longer, when I put it in park yesterday it reved up then back to normal. But I noticed it felt differant before I noticed the OD light flashing.

After the whole stalling episode for a year, my Waite to start light stopped working, fixed that, now this! Starting to loose a little faith in this truck. Sad part is, only has a 130k miles.

Have you checked the fuses and relays under the hood? There is one I used to pull when I would park at the airport that would let it turn over but not fire. Is your 'Wait to Start' light coming on when you turn the ignition on?

If you have a chip, you may want to unplug it as well.

I put my chip back to stock. No warnings on the dash and the glow plugs system is working right. I am going to try and pull fuses and push them back in. I am starting to think i lost the ecm. Which fuse blows when the fuel bowl heater goes? The truck runs once the it's reflashed and the codes erased then if it sits it just turns over and no start.

If you are able to pull codes and the wait to start light is working, it's not the fuel bowl heater fuse. I would try unplugging the idm and re-plugging while cranking as suggested above. Good luck!

[QUOTE=Rwbrew3;3885470]Rick,

My light only flashed while driving and was very intermittent. All your symptoms are very close to mine. Have you pulled the trans codes? Try driving the truck with the alternator unplugged, see if that stops the flashing.

My 96 f350 7.3 150,000 miles had an intermittent problem.it would quit running and you could restart it in one to ten minutes.It would run for one minute to six weeks. replaced cps nothing replaced icm (injector control module) hasn't quit running in two years. $1000.00 at ford found a new in box ford icm on ebay for $550.00. Good luck with your 7.3 .

Did you put the chip on the stock setting, or did you remove it completely? It still has signal running through it if you have one of the ones (like I do, Bully Dog 6 position), which has the Stock|1|2|3|HighIdle|Valet modes. My chip used to act squirrelly, but has seemed to iron itself out.

I'd remove it's plug from the ECM if possible.

Is the high pressure fuel pump staying full of oil ?

[QUOTE=RT930turbo;3885607]Had the trans scanned this morning, deffinatley going out.. Not sure what he code was but my mechanic said it's Time to rebuild it! Did say I could dive it as is for a while!

$3300 to fix.....OUCH!!!

Artie....I never unplugged the alternator, figured after the code came up there was no need, think I should still try?

.. without knowing code its a hit or miss you can try the alternator.. we ran across the same thing on a older body style auto we rebuilt the trans in .. kept setting 2 different codes i cant remember what they where but i scanned it and drove it we even pulled a trailer with it.. they where false alternator was doing same thing to it..

I would try it for sure! Not sure what code he saw, but even if it was an input shaft/output shaft mis-compare (indicating slip) this could all be caused by screwy speed sensor signals. If you or your tech have access to a scan tool that will allow you to read sensor data live pull up the following parameters:

RPM
TSS
OSS
VSS
Selected Gear

If you are getting interference, one or all of these values will be all over the place when the truck is sitting still and you change the rpm in Park or Neutral. When I unplugged the alternator, they immediately settled down and everything was normal. I have an old oscilloscope, and sure enough when I scoped the alternator, it was 100% the culprit.

It sounds crazy, but it sure beats a trans rebuild! (mine only had about 10k miles on it, so I was VERY relieved it was not a major issue.)

Good luck.

fixx
 

[QUOTE=Rwbrew3;3885847]that is way too much to rebuild a trand,,2k tops....try this,,pull the VSS out of the top of the rear diff,clean it and put it back in,,they usually get covered with metal shaving's from the gears chaffing..this will also throw off the VSS and make it shift wierd..when the newer electronic ford trans start to go you will have to petal shift it and it will slam into the next gear..

New swamp diesel idm which supposed gives it 30 hp more. It goes in tomorrow with the inner fender off to access the wiring.

I will look at the alternator in the am but it reads good on the amp gauge . The chip is a superchip so I was able to eliminate it and program it back to stock.

I think we have 2 different threads wrapped up into one :lolhit:

I don't think the alternator is your issue...

fixx
 

plug it in on the block heater cord,let it sit over nite,if it starts but with a long crank time then its the idm..

Thanks for the info!! Im going to try it this weekend!!

[QUOTE=mrfixxall;3885910]Thanks, I'm deffinatley going to try all mentioned, $3300 to rebuild is crazy for sure!!

Sorry for the high jacking!!

If the IDM doesn't fix it I had a simliar problem and it turned out to be the IPR harness (located on the back of the HPOP). The harness wasn't making good connection - consequently it wasn't telling the PCM that the HPOP had generated 500lbs of pressure required to fire the injectors. You might want to look there.

There is also a kind of poorly designed bronze nut on the back of the IPR that sometimes works its way loose and creates a similiar situation.

Good Luck - I just sold my 7.3 on Monday, but miss it already.

EDIT - I got lots of funny codes when this was happening including IDM, PCM, etc.....

thanks, checking it out now.

Either of you guys have any luck?

Mine got towed in yesterday. Went over everything . I really think it's the pcm but want it scaned before I throw more parts at it. Everyone i ask about their trucks has 2-300000 miles on them with hardly any issues so this is just a fluke. At least with the swamp IDM it will be a little faster when I get it back.

My transmission is a hit and miss, some days it acts up, and others its like nothing is wrong! Did not have the chance to do anything to it this weekend.. never had a single issue till last year, stalling for no reason, then no starts, to the trans problem im currently having! loosing faith in her!

That stalling for no reason and then no start could be the crank position sensor, that is what mine did and if I remember correctly when it would not start you could get it to reset by cycling the ignition key to on, I think you had to do it 5 times. When mine quit there just happened to be a diesel mechanic across the street that told me that and it worked.

Rwbrew3 , your stalling may be the cam positioning sensor ? I have a 7.3 in my work truck with over 500k and still runs great :drink:

If your torque converter is f.g up fix it now and maybe you can save your trans. Mine has had minor problem for about 4 months , broken starter wire then the starter after that now a no start issue and the water pump is leaking. The truck has low miles and is clean, the alternative is a 50g new truck, can't do that.

It turned out to be wiring harness problems from the idm to injectors and also replaced the injector harness under the valve covers because the connectors were f..g up and throwing codes. Had them replace the glow plug solenoids at the same time because they seemed to be hotter than normal. The idm was still good but in my throwing parts at it trouble shooting ,it was replaced with a Swamp diesel performance one. you can feel the difference and there is more power. Now a water pump and a couple of rusty power steering lines., and then it will be time for brakes. Thanks for all the responses.

Ok, the high side of the injector voltage is 100v. That is why the harnesses are marked in red tape. Please be careful. Also, the IDM (injector driver module) senses a fault on one injector it will shut off the card in the IDM that controls an entire bank. You could have something odd, like a circuit low on one injector on the lh bank and the UVC harness disconnected on the rh bank. You need 500psi of high pressure oil before the IDM will even think about sending voltage to the injectors. Ck the obvious first, fuel and oil. Ck and make sure you have module prove out. When you turn the key to run the ck engine lamp and glow plug wait to start lamp should illuminate. Also, you should hear that loud "snap" of the glow plug relay closing. The dash lamps and interior lamps will dim due to the large load of the glow plug system.

This may seem odd but i see it lots. Make damn sure that the battery terminals are clean and tight makes sure the pinch bolts move in those old lead terminals. make sure the posts and terminals are clean. also make sure you are starting with two good batteries. During glow plug operation and cranking... If you drop below 8v the modules like PCM and IDM will go to sleep.

Rick is it a transmission problem or in the column ? have seen pinched wires in the steering column when you move the shifter to 1/2/D even seen them pop fuses and truck stalls till a new fuse is installed under the dash . don't lose faith