Ford 7.3L Power Stroke (1999-2003) :: Engine Missing / Bucking At WOT
Apr 9, 2017
I have been having a problem for a while now where my truck will miss/buck at WOT. This only happens at higher RPM's. From a standing start 0-60 it is fine. However when I downshift full throttle from about 50 MPH it initially goes, but then it will miss/buck consistently until I back off the throttle.
I have so far replaced the CPS, re torqued injectors, checked valve cover harnesses and fuel pressure stays in between 64-58 full throttle. No codes show up.
My truck runs great except as I described above. I would think an injector or two are bad, but the truck runs and idles great. My initial guess was that it was a fuel pressure issue, but fuel pressure holds strong. Could it be air in the fuel?
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Truck is bucking and missing every 10 seconds or so and will stall when taking off in drive sometimes but fires right back up? I got a lot of codes in the torque pro app but some are in grey. Not sure what that means. EGR has been deleted so that's why I got those codes. I was cleaning the back of the truck the other day and found a can of quick start . Guess that might be why i got codes for glow plugs also. I'm gonna post up pic of my codes and numbers of truck running at idle in drive. So far I see I got a code for cylinder 6 contribution? It's in grey tho whatever that means.
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just overhauled my 6.0. run great for about 3 days now runs really rough when cold. new heads injectors rings pistons ficm fuel pump icp sensor ipr valve fuel pressure is good. Engine rolls smoothly when cold also.
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If I don't keep her plugged in she starts hard, bucking etc. I'm thinking GP or GP relay but I`m not getting any thrown codes. Talking about *30-*50 outside, when its warm starts normally.
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I have recently picked up an older F350 2WD 7.3 DRW Lariat. the price was right higher miles but hey it is a 7.3, overall in very good shape.
So the issue at hand is the truck runs great most of the time and puttering around at city speeds you would never know there is any issue;
Get the truck out on the highway set the cruse at 70 to 72 and if you hit a rise in the road or other reason to slightly accelerate the truck chugs and bucks. For lack of a better description it goes chug chug chug, if you accelerate harder to downshift it goes away or if you back off the throttle it goes away. This happens with cruse on or off, a steady foot on the pedal will cause this as well.
I have also noticed that when you let off the throttle the sound the truck makes de-fueling is just very different and "off" sounding . Not sure how to describe it but it sounds funky ... clearly not right when compared to other 7.3 or my 6.0 truck.
What I have done, :
1. Had the truck scanned with an AE and a snap-on scanner both show no codes ran injector tests no contribution errors, not even in # 8.
2. Changed fuel filter
3. Changed Oil and Filters ( tried both full synthetic Rotella and Dino oil looking for a difference )
4. Cleaned out the fuel filter housing just in case.
5. Confirmed injector O-Rings are not leaking
This feels like a fuel issue, my next thought was start looking at fuel pressure under load at speed to see if there was a drop when this is happening ?
Is there a way to test fuel pumps in this truck ? Maybe a clogged pick-up screen ? Where do I start looking next ? I have reasonable mechanical skills but don't know this motor very well, this doesn't seem like a CPS issue..
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2000 Ford Excursion, 7.3 PS with 210,000 miles. I am on I40 at a truckstop. I was rolling down the freeway last night when the truck started bucking. I pulled of the freeway and here came a thunderstorm. I waited til this morning to check for codes cheap scanner. I pulled a code P1211. I waited for NAPA to open so I could take it in the shorts. I bought a fuel filter and an ICP sensor. After changing them out, the truck runs then starts missing. My battery is about to die so I will finish post shortly.
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165k miles 4x4 6 speed, bone stock unmolested
Slowly progressing problem over 6 months. Occasional miss at highway speeds uphill has progressed to bucking and jerking during even gentle acceleration attempts.
I hadn't got my cam sensor recall done but no change after that procedure completed yesterday. Oil recently changed as well.
I have a torque pro but it never finds any fault codes even though 'service engine' light comes on sporadically. I'm not sure I'm operating it properly but it at least reads rpm when its running.
I'm contemplating the hutch mod but I'd like to have an official diagnosis beforehand if its possible in my case.
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2000 F250, 7.3, 170K, running rough, knocking loudly, missing, shaking, no power to get up driveway, intermittent, no codes spit out at all. No smoke visible, no leaks visible, New fuel filter, air filter, update cam sensor, new fuel rail lift pump, new uvc harness, new glow plug relay.
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1994 f250 7.3 turbo problem.. runs great on the level.. Cruises 65 no problem.. We have an 8% grade coming from town and half way up it starts cutting out and sounds like a jack brake under the hood and loses power.. Once over the top it clears out and runs fine again.... I just changed the fuel filters but no luck... I have been wrenching on cars all my life but no diesels..
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My 02 excursion is missing at idle and jars the whole truck around going approx 50mph feels like good amount of power loss but still pushing 30psi boost, just got autoenginuity all injectors buzz fine on the test, contribution test show balance fault in cylinders 1&8, should I look for o-rings to be bad, uvch, cups cracked or what ----- turbo fine, hpop great condition, new IPR, new fuel pump and hutch mod, about. 250k miles on truck nothing else major showed up on ae.
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I have a 2002 7.3l with 229k miles. So I am having a big problem now missing oil! My reservoir is empty and my dip stick is reading low, and i just put 16 quarts in yesterday with the new filter! im having a long start issue obviously because i don't have any oil supply! just drove the truck today, ran great been having this issue for the past week. here are the details. i came up from Texas after installing joeys t500 pump, when i arrived to California there was oil everywhere! my pump that joey rebuilt had an issue so he sent me another and bam! runs great no probs, now after about to weeks and about 15 degree temp drop i get hard starting. first time instead of a 2 second start up it took 9 seconds, now it takes anywhere from 9-20 seconds to start! so after my drive today i let it sit for about 3 hours seeing if maybe i had air in the lines from the res not being full, well now i cant get a start at all my res is empty and my dipstick shows little oil, i just replaced the icp. ipr, and eot when i put the first pump in, could this be the lpop?
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I have a 99 f450 with a 7.3. Here lately it has been "missing" when driving or idling, but only every now and then. When driving down the road it will start bucking and boiling black smoke out then the ses light will come on and like turning a switch everything clears up and it acts and drives normal.
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2001 193K miles. Has a miss, like starving for fuel. Starts fine and it will clear out at higher RPM, 1800 and up. idles...
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I have a 2001 7.3 that almost has everything practically brand new... new hpop, water pump, uvch, gpr, glow plugs, icp sensor, ipr sensor, cps and new turbo pedestal that was leaking oil, well now my truck has a cold start to where it has to be plugged in to start and when it finally does it smokes white pretty bad, misses and sounds like it's jumping around under the hood up until it warms up and revs fine with less white smoke but still a miss!!
Compression on test has been done, and good, fuel pressure is good, but the buzz test when cold shows 123457 muffled and quite and when the truck is warm only 3 and 4 are still muffled and quite? Injectors sticking?? Or just need New injectors!
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My feed truck (2001 ext cab 4x4 7.3 198k) had a cold starting issue I fixed with new gp relay. Now I noticed when it gets down below 30 degrees it has a cylinder miss until motor warms up. I don't doubt injectors are in my future. I was wondering though if that is common for worn injectors or if maybe something else has gone haywire and how long can I run it like that before something else tears up? after about 7-10 min the miss goes away and I don't notice it. I would like to get through the winter before messing with it or having injectors put in it...
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My truck was shuddering in od. So as I last effort thinking it might be injectors I pulled all of them and replaced all of the orings and valve cover harnesses. After all of this was done seemed to do nothing at all. Now a new problem has surfaced. It's having idle problems. It will now idle at 780-850 instead of 650-700rmps. Also on deceleration it will miss pretty bad. Checked all of my injectors again all connections are good and all of the injectors are tight. Not burning any oil. So I unplugged the icp and bam runs like a top perfect running engine. So I bought a new one and plugged it in and itake doing the same thing. So what is going on! Also it was throwing a random check engine light but wouldn't bring a code up I'm completely lost....
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I purchased a 2000 7.3 dually 4x4 and the driver side battery is missing with the cables snipped.
I noticed the headlights do not function, neither do the brights, the air does not blow. Is this related to the missing battery? Someone said they are on same circuit and dont do separate tasks.
Still starts runs drives fine...
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Just picked up a 99 F250 7.3 Stroker, it had sat for two years in a warehouse, the truck had just had reman injectors put in right before it was parked. We fired it up, and it was missing, and smoking a lot (light blue, almost white) I checked the oil filler cap, and no water on it, after it ran for a while, it stopped. Shut it down, went and got my trailer ready to load the truck, fired it up, and no smoke to speak of, by the time I got it to my trailer, still no smoke.
I revved it against the governor a few times, hoping to clear the miss (figured may have been trash, or a sticky injector from sitting so long) It is turned up pretty good, as it came with a Superchip Super Tuner. It seems to hit on all eight above 2500 RPM or so. Brought it home, and took it out on the road, it seems to only miss under 2500 RPM or so. I took of from a dead stop, then got on it hard at about 15 to 20 MPH, it took of nice, then all of a sudden, the tach started climbing like the trans was slipping, looked in the mirror, and the tires were smoking, guess they broke loose when the boost came in!
I let it idle and warm up for a good half hour and noticed a lot of pure white smoke coming from the exhaust, went back to it and it was steam, I took the oil filler cap off, and there was a lot of steam coming out of there, pulled the dipstick, more steam, I then noticed the degas bottle was low, I topped it off, and got in the truck, and revved it a few times, then held it at 2500 RPM for about a minute, It started blowing water out from under the degas bottle cap. I called the guy I got it from, and he did NOT put new injector sleeves in when he did the injectors, I don't see any oil in the water, but there is water getting on the oil filler cap now! Does it sound like a head gasket, or an injector sleeve?
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Lately I have been having problems loosing power. Truck wants to miss mostly going up hill and runs sluggish I'll pull off the road and let it idle for a minute and it will run fine. And it is only occasionally some days it don't happen at all and other days it happens quit often. New fuel filter, oil is good, had it on the scanner and isn't throwing any codes. Around 230k miles newer injectors.
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1999 F250 7.3 .. The truck seems to idle fine and and runs smooth all the way up top cruising speed, but when it levels out at say 65mph then it starts missing and jumping. I can ease into the throttle a little and it smooths out up until it levels out again.
I have the Vgate Elm and Car Guage Pro and a couple of other apps and the only DTCs I'm getting anymore are:
P0541 Intake Air Heater Circuit Low
P0640 Intake Air Heater Control Circuit
But from what I've read, neither of those should cause this issue.
Buzz test sounds good.
Cylinder Contribution test throws code for #4 Cylinder
I'm trying to do everything possible before throwing an injector in it.
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I have a '99 F250 SD 7.3 & im going on a trip next weekend so I thought I'd pull the exhaust pressure sensor & clean the tube in an attempt to get better mileage. Found the sensor & unplugged it. Went to the manifold & started removing the tube when it fell off. 6" from the manifold it's broke & the rest is completely missing.
Autozone doesn't carry this tube so, how important is this sensor?
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