Ford 7.3L Power Stroke (1999-2003) :: Hesitation When Accelerating At Speed
Nov 27, 2015
When I'm driving at highway speed and press the accelerator after coasting a bit, the engine stumbles then picks up and accelerates. The fuel bowl assembly is brand new as of 5 months ago, and I drained of any water last month when I changed oil. Truck is stock with 350k miles.
Apart from this issue, it runs well and idles smoothly. Injectors are healthy per a buzz test a powerstroke mechanic performed last year. What could cause the stumble off idle?
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My truck - early 2000 CC short bed, 300K miles
Background on my problem: I had a short list of long overdue maintenance and updates to do that time and money kept me from tackling. Found a little of both so I replaced the water pump, HPOP lines, re O-ringed the HPOP/IPR, deleted the AIH, replaced all of the brake lines in the engine bay, put new fuel lines to the filter bowl. All of this took me about 2 weeks so the truck sat with the batteries out for that long.
After buttoning it all up, it fired right up, a little slower than normal but figured that was air in the fuel lines, HPOP, etc. The only issue I had was the battery light stayed on. Thinking I had an alternator issue, I checked it and it was getting about 14.25v so figured that was good. I used it regularly for about 3 weeks, the light stayed on, and noticed some surging during warm up and some low rpm hesitation.
Then it stop dead on me driving down the road. Turns out it was all my doing, I had torqued the bolts on the water pump pulley but didn't use Locktite. The bolts backed out, shredded the belt, and ended up yanking the CPS wire harness out of the sensor. So that made total sense.
Fast forward another week, got new wiring pigtail and CPS (never replaced it before now) from a couple of the good FTE vendors. I am not sure about the wiring on the pigtail, my truck has a green, blue and brown/gray wires, the wiring diagram I found online showed green, blue and gray. I wired it connecting the brown/gray where the gray line goes (center contact) and closed everything up.
Another thing to mention is that I have an Edge Juice with Attitude that has been on the truck since '06. I lost that connector in the process and they were absolutely no support in trying to get me running again. Wouldn't or couldn't tell me which wire they connect to so I used the green wire which is the CPS signal wire to the ECM. Once I am running again, going to get rid of the Edge.
So that is where I am now. No start, I've been reading some of the "what to do" posts, the most likely is that I don't see the tach bounce when trying to start. So I want to check the wiring to make sure I have good connections to the CPS.
So I don't have any diagnostic software to read codes, etc. I really need to fix this myself and only have one set of hands most of the time. Not really sure what the problem was before it stopped running and now I can't diagnose the surging and hesitating.
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I have hesitation as I accelerate especially starting from a stop. It will continue until cruising speed. Funny thing is when I put the cruse control on the hesitation stops and it runs fine. If I want to accelerate while on cruse the hesitation starts again until I let off the accelerator. Is it the TPS ? I changed it two months ago.
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My issue can be while driving with cruise on, or accelerating, the truck just losses power, then recovers. At idle, the rpm can, but not always, fluctuate.
There is no "misfire" when it happens, but it just falls on its face. I have NO diagnostic tools, and my injectors are not stock, so I am unable to unplug my DP.
My thoughts are to unplug the ICP and give that a shot? Meanwhile, I will put in a order for a elm327
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As I was getting ready to leave town with the tractor loaded up, I was accelerating with the turbo spooling up when I heard a bit of a pop and lost power (engine still running and all, just very low power like you get when the turbo fails). I wasn't far from the shop so I came back and started getting a lot of white smoke out of the exhaust, it doesn't smell like diesel, probably more like oil. Definitely smoke, not coolant. I pulled it around back and shut it down to go grab AE and scan it and it shows a P0475, starting it back up has light smoke at idle and it idles fine but as soon as you give it any throttle it starts smoking pretty badly.
Researching it looks like the most likely cause for this is the EBPV itself but before tearing it down that far. This is the only code it's showing.
Truck has 272k on it, turbo was rebuilt a couple of years ago but we didn't do anything with the pedestal at that time. I guess in retrospect, I probably should have done the EBPV delete and the resistor fix then but I didn't think about it at the time.
On another note, my AE is not showing any of the system test for some reason, the drop down is blank. I have version 7.0.1, so it's an old version but I'm working on an old truck, so... What that might be? I've got the truck pulled into the shop now to let it cool down. I'll probably let it sit overnight and take the turbo and EBPV out tomorrow unless someone has a better suggestion...
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Last night I bought 2000 F250, 346k on it... Crew cab short bed 4x4 with ranch hand bumpers like I wanted .... Headed back home (Miami FL ~1100mi) and covered about 200 miles @70-75mph before i ran into few problems ....
First off, while cruising I noticed slight hesitation in the throttle, with loss of speed regardless of pedal pressure, noticeable on inclines. It would go away on downhill and get smooth response again and pick up speed. This went on for about 40 miles.
Then I noticed heater blower stop blowing hot and start blowing cold, without me changing any settings. At the same moment, I noticed temp gauge move up and I hit next exit offramp to check what's up. During right turn at the end of off ramp truck stalled. Pulled to the shoulder, and popped hood.
Noticed empty degass/overflow bottle. Carefully opened lid and water gushed up to the top. When all pressure slowly released, water pulled down and emptied the bottle. Both upper and lower radiator hoses are empty. Engine oil has no traces of water tho. There were no leaks under the truck. I then tried to fire up the truck to get me to the gas station 1/8th mile away.
No crank in Park. WTS comes on and goes off. Cranks in Neutral, RPMs come up some, oil pressure shoots up to normal running position, but won't fire. Tried a while then gave up as not to kill starter and batteries completely.
Fuel pump works 20 sec then shuts off. There is fuel in bowl. I covered 140 miles since last full fill up, so not fuel pickup issue I don't think.
Summary
Have crank
Have RPM
Have oil pressure
Have fuel
Have (had) batteries, now not so hot
It's cold out ....
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My fuel gauge on my Sport Trac is nowhere near accurate. Ran out of gas the other day showing 1/4 tank.
I get a little hesitation as well when accelerating.
I'm showing a PO191 fault code which says Fuel rail sensor.
Would that cause a gauge to malfunction?
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(2000 F-350, 7.3L, 205k miles) Over this weekend, I noticed while driving mostly in the lower gears, that there was a slight hesitation with the throttle pedal depressed about half way or less. Seem to get worse as the day went by, but no lights or anything came on. Changed the fuel filter and added a fuel injection cleaner to the tank. Checked the oil and it was low, so I filled it to the correct amount.
Drove it around the next day, and it seemed to be good, until it warmed up some, and continued to hesitate. The hesitation seems as if it's not getting constant fuel, and the truck jerks a little. Once you get up to over 2000 rpms, it goes away. Looking up other reviews on similar issues, most have pointed to the throttle pedal sensor and just changed out the pedal assembly. Before I take it that far, I wanted to see what was the corrective action.
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I have a early 99 7.3l that seem to cut out and shudder while accelerating at low rpm's below 2000 once I am above 2000 rpm it seems to go away similar to a dirty carburetor thinking injector problem...
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I've been trying to track down a lack of power with my 7.3 for a few months now. I've had the truck for 8 years and there's just something off with it lately. When warm under a light load, such as accelerating while cruising at 40mph or going up a light hill at 30mph+, around 1100 to 1400rpm, there's just a distinct lack of power.
The engine starts lugging and the injector or valve noise increases dramatically until I push the throttle down far enough (60%+) for the transmission to downshift. Once it downshifts the engine sounds normal and takes off like it should.
At higher RPMs, it's seems to run okay, but it feels a bit down on power there. Otherwise, it starts great, idles pretty well with a slight miss, and no smoke that I've been able to see.
When it's dead cold in the morning, it seems to run better than any other time of the day.
I don't have any trouble codes other than a disconnected EPBV. One morning I did get P1670 when the engine nearly died when coming to a stop. I'm chalking that one up as a fluke due to a broken valve cover harness connector tab.
The truck has 170k miles and is mostly stock: AFE intake, 4" exhaust, and no muffler. It has an old Edge Evo programmer (yeah, yeah) that I removed a while back. I going to put it back on so I can monitor my EGTs.
The ICP, IPR%, and boost are all within spec. Buzz test sounds fine. CCT says #8 is bad with the grey CPS. Here's a datalog of a full throttle 70mph run.
[URL] ......
Recently I've decided to fix known problems:
HPOP line leak to the driver side bank
All Injector O-rings (black diesel in fuel bowl, suspicious oil consumption)
Replaced leaking intercooler couplers
EBP tube clogged, causing 0 boost sporadically, bypassed it by teeing into MAP sensor hose.
Various cam position sensors: grey (B), new dark blue (C)
Replaced leaking ICP sensor with generic sensor 6 months ago and unfortunately can't find original to test with. 2900psi without a tune seems a bit high, but reads consistently otherwise.
New fuel pump
Added service port to fuel bowl and measured 60-64psi at idle
Some things I have left to try:
Measure fuel pressure under load
Try out a parts store CPS I forgot I had.
Ziptie/secure broken valve cover harness connectors
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I just wrapped up a full day's worth of tear down/reassembly chasing an oil leak at the turbo pedestal. while I had the turbo out I replaced the pedestal with a non-ebpv pedestal and replaced the outlet with a high flow outlet. I also removed the stock exhaust and replaced it with a 4" Turbo Back from MRPB. Once I got everything put back together I hit the highway to check out the new exhaust.
To my horror I started to hear a high pitched airhorn-like sound while accelerating. It sounds a lot like an old police siren... I'm wondering if this sounds like a turbo or simply a boost leak. I obviously had everything taken apart so a boost leak seems likely (still original boots with 191,000 miles). I've ordered new boots from RiffRaff but wanted to make sure it didn't sound like an exploding turbo and that I could safely drive it until I can fix the old boots.
Take a look (listen) at the video : [URL] ....
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Background: '01 Excursion 7.3 4WD, 264,xxx miles, batteries less than three years old, new alternator [URL] .... , using an Edge Insight for digital readings.
Problem: I replaced the alternator about three weeks ago, first week all normal. Second week alt/battery idiot light comes on, then to add more frustration it is consistently inconsistent in its reading.
The volts (upon starting) jump around 11.6 - 12.1 when first starting. The light comes on while accelerating and goes off during no throttle while cold.
After warm-up the light will come on intermittently even though the reading is 13.0>, but never during off throttle.
It seems to do this more when cold but it does not completely stop when it's warm. Yes, I don't think that should be a factor but it is a reality .
I'm thinking it's a bad voltage regulator.
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I drive a new to me 2005 F350, he has a 2001 F350. While we were talking he said he didn't think his pickup had the power it should have. He pulls a 5th wheel camper that weighs around 8000 pounds fully loaded. He said it takes a couple of miles to get to 55 mph, and it is hard to hold the speed. It doesn't have the power it did when he first got it last year. He was told that a diesel is slow getting started. He rode with me in mine, when I dropped it about half throttle to pass a slow car he said he could tell mine had way more power.
His check engine light is not on, it starts good both when hot and when cold. It runs smooth, no miss as far as I can tell listening to it. What are some common issues that could cause this? He did just change the oil and fuel filters, not sure about the air filter. He said the power loss came before he serviced the engine, and did not improve after the fuel filter change. Where to start? He was also told to check the filter inside of his fuel tank, so he is getting ready to drop his tank.
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I got a p0284 code and have some symptoms such as shaking while accelerating between 45 and 60 mph and a rough idle.
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Like the title says my truck has been stalling while driving. Accelerating or cruising it dies for a second, two at the most, and then just keeps chugging along again.
I thought i'd fixed the problem last year when I did injector O-rings and 50 cented my UVCH. It hadn't done it since, until two days ago. Started out with a two good solid stalls while gently accelerating up hill. I had thought maybe my fuel pickup foot had finely given up the ghost because I was below a quarter tank. But I filled her up full, and then she did it again about 50 miles of driving later.
I didn't catch the first four stalls on my torque app, because I'd just recently decided to stop logging every trip, with the thinking that it had been half a year problem free, why keep logging waiting for something that isn't going to happen. I did catch the 5th stall on the torque log. But I'm having trouble trying to figure out where it happened in a 30 min log.
First question where would yall start in tracking this thing down? Next what data actually should be logged? I think I've got some extra stuff in my logs that isn't necessary, and is maybe bogging down the system. I get one data point per second resolution on my logs. Are there ways to improve the resolution, will getting rid of some PIDs work?
Lastly I need to attack this thing smartly, without throwing time and money at unneeded parts. I had surgery and I've been out of work for 3 months and I'm looking at another 6 before I'm making money again, and there is no unemployment for the self employed. Also I only get 3-4 light weight upright hours a day to work, exceed that and I'm back on the couch battling swelling for a week.
Also is there anything I can do while driving to "flag" the stalls so I can find them more easily in the logs?
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when i accelerate or let off the peddle I hear and aloud thug or dull bang. I've checked and greased all the u joints. Disconnected the carrier bearing and separated the drive shaft and greased it up. Still get the noise I have very little play in the carrier bearing but I don't think that's the problem. It sounds to me like might be at the transmission. What do y'all think it is?
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Truck (02' , 7.3 ) has check engine light and since I'm on vacation don't have access to my Autoenginuity diagnostic software, so looks like I'll have to go a auto parts outlet to get the code read.
But.... before I do I wanted to get some input from y'all. Basically what happens is the idle goes up while in gear and when I put it in neutral, idle goes back down to normal. In addition I noticed (yesterday) somewhat of a lope or stumble at idle while in gear. No stalling and no effect to fuel mileage.
Since I'm away and away from my tools I'm somewhat limited. Certainly once I get the code I'll know more.
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What is the speed you have to be driving before the airbag will pop off in the event of a frontal collision? just wondering.
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2001 ford excursion 7.3l diesel.
So I tried to go to work today but the truck said no. it started out fine then out of no where it felt as if someone slammed on the back brakes engine still revved up like normal just didn't want to go. speed dropped to 20mph then i heard a clunk. after that it was fine until it hit 20 mph again. it did the same thing again.
So I got mad at it thinking the trans went out gave it the beans and it shifts into all gears but did not feel like it had power. i did pull over and check the fluid looked a little orange. when got back in the truck i did notice the od off light blinking?? drove the truck home was shifting fine but hear this awesome sounded like a hand grenade rattling around underneath. when i got home notice fluid coming from the bell housing(out of the bottom).
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Ok I have had this noise going on for about 1 week before transmission went out. I just built the trans and its still there.
I had a mishap years back with front end hub bearings so I replaced with New Timken Bearings. Well that wasn't it but at least I know where I
stand with those. It starts making a noise when slowing down about 3-5 seconds before coming to a stop. I thought maybe the carrier bearing in
driveshaft?
Pinion bearing in rear diff? I need to service the parking brakes on rear so I may pull it down and go through it.
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I am having trouble with my 1999 F350 Ford Powerstroke, Looses power but the motor never quits and also starts up fine, will set and run and warm up on the coldest morningIdles fine, It will hold back sometimes and not increase speed. I can take it out today and it may be fine and tomorrow can't run 2 miles. I was thinking CPS but after reading information I am not sure. What may be causing this issue. I just put a High Pressure oil pump on it could this have anything to do with it. Was not having a problem before the pump was changed. The pickup has 190,000 on it actual miles.
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