Ford 6.0L Power Stroke Diesel :: Subtle Engine Sound Changes While Driving At Highway Speeds - Surging
I've been noticing some weird, very subtle engine sound changes while driving at highway speeds lately. Something almost like surging, but not. I don't know how to describe it. I might try to make an audio recording next time I take it out so I can explain it.
Anyway, I don't know why but ICP popped into my head. Maybe, for some reason, the engine was varying ICP causing the surging sounds.
So I hooked up AE and did a test. I've attached a screen shot.
With my idle speed actuated as high as it will go, and ICP actuated as high as it can go, I can only get a pressure of about 1450 PSI. I always thought ICP should go higher than that. I seem to recall reading somewhere around 3600 PSI.
So am I misinformed, am I reading the data wrong or do I have a problem? How high should Injector Control Pressure go? I missed it in the screen shot, but ICP is actuated to 100%.
Ford 7.3L Power Stroke (1999-2003) :: Strange Noise Occurs At Both Highway And Surface Street Speeds - Throttle Related
I have a strange noise that occurs at both highway and surface street speeds. On surface streets at low speeds 45 mph and under, if I let off accelerator to coast and lightly step on accelerator I get this quick sharp noise.
Everything I have read regarding a similar noise is under load and being described as a turbo fart. Clearly I am not under any load. I'm lost.
Definitely not a low woooo noise. Also not a hard accel and release and definitely no chuckle and or popping. The sound is high pitched and quick, roughly .5 to 1 second at most. The sound is more like a "zzzrrp" or "zzzoop". I can replicate the sound 50% of the time easily at speeds under 45 mph by briefly coasting (no accelerator) and lightly tapping the accelerator and releasing or holding. Occasionally this sound will occur at full stop when I step off of the brake pedal and before I step on the accelerator. This sound can also occasionally be heard at highway speeds under similar accelerator conditions though it may be more frequent and I just don't notice it.
Would this condition throw a code? Just received "Total Ford Scan Tool Package Enhanced Bundle SP03" scanner from autoengenuity. Hoping to put it through its paces tomorrow.
Additional info: 145k miles. Injectors serviced by a reputable diesel shop here in Vegas approximately 1.5 years ago. Unknown oil leak where oil is collecting in the valley on top of the engine beneath the turbo. HPOP seals were replaced roughly 1 year ago at another reputable diesel shop here in Vegas. Still have an oil leak (turbo related?) Oil is under 500 miles old and acceptable level. Fuel filter is due for a change but that does not seem to affect condition. Air filter 1000 miles. Thinking about upgrading to AIS severe duty kit soon.
Ford 7.3L Power Stroke (1999-2003) :: F350 - Surging And Rough Idle While Driving
I have an early 99 F-350 with 268K miles. It is bone stock right down to the factory exhaust. A couple months ago I started have a rough idle and surging while driving problem. I never got a check engine light but I borrowed a scan tool from a friend and pulled the following codes: P1690 (wastegate solenoid), P0381 (glow plug circuit malfunction), P0269 Cylinder 3 Contribution/Balance Fault, and P0284 Cylinder 8 Contribution/Balance Fault.
I did some research and everything I read said it was most likely the CPS. So I changed the CPS. The truck ran fine for for a few days but then it started acting up again occasionally. I noticed that most of the time when it acted up was at start up when the engine was cold and I also figured out that if I shut the truck off and re-started it (sometimes I had to do it 2 or 3 times) it would clear up and run normal.
A buddy of mine that has a 2000 F-250 said he had a similar problem with his truck and it ended up being the ICP sensor. We switched his ICP with mine and I changed my oil at the same time (because it was due for an oil change). My truck ran flawless for over 2-weeks (over 200 miles) so I put a new ICP in my truck. Note: my buddy did not experience any problems with his truck with my ICP in it.
I've put about 700 miles on the new IPR and the truck has started to act up again. Once again shutting the truck off & re-starting it will clear it up and still no check engine light. I took it to a local "diesel specialty shop" while it was running rough and they hooked it to their scanner and got P1280 (Inj. Control Pressure Low), P1690 (Wastegate Solenoid Fault), P0381 (Glow Plug Indicator), P0269 Cylinder 3 Contribution / Balance Fault, and P0284 Cylinder 8 Contribution / Balance Fault.
They never did anything other than hook it to a machine & check the codes but their diagnosis is my High Pressure Oil Pump is going bad and my #3 and #8 injectors are going bad. They recommended I let them replace all 8 injectors and the High Pressure Oil Pump. The problem I have is they can't give me a REASONABLE explanation as to why re-starting the truck a few times clears up the problem.
Ford 7.3L Power Stroke (1999-2003) :: Clunk / Vibration When Traveling At Highway Speeds
I'm a mechanic but work only on cars so I'm a little shy on diagnosing trucks. I have a 2001 7.3 f250 4x4 short bed, when I give it gas I can hear a clunk, when I let off of the gas I also hear a clunk. Also when traveling at high way speeds I can feel a strong vibration when I very lightly give it gas but the vibration goes away as I give it more gas.
View 5 RepliesFord 7.3L Power Stroke (1999-2003) :: Intermittent Engine Light / Momentary Surge At Highway Speeds
I have a 1999 F350 200,000 miles. Now getting an intermittent engine light. Still runs well, although once or twice I felt a momentary surge at highway speeds. The light is on intermittently about 1/2 time. I read the codes and the following codes, as in the thread title, came up:
P0280 - ICP circuit out of range - low
P0113 - intake air temp sensor circuit - high input
P0470 - Exhaust back pressure sensor circuit malfunction
P0478 - Exhaust pressure control valve - high input
What would make these all code at the same time? Would these not make a noticeable problem driving? And how do I resolve these?
Ford 7.3L Power Stroke (1999-2003) :: 2000 - Occasional Miss At Highway Speeds / Bucking And Jerking During Even Gentle Acceleration
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.
Ford 7.3L Power Stroke (1999-2003) :: Smoke For About 10 - 15 Seconds Pretty Heavily When Slow Down After Highway Speed Driving
Been barely driving my super duty due to it having a multitude of issues. So working on getting this thing back to some semblance of running decently and it has been smoking whitish blue, oil smoke out the exhaust. Not constantly, intermittently as far as I can tell.
If I drive it at highway speeds for 5-10 minutes then slow down it will smoke for about 10-15 seconds pretty heavily. Yesterday I got off the beltway after running for 15 minutes, it didn't seem to be smoking, but about 1 mile to 1 and half miles later, pulled into a convenience store and it was like I was spraying for mosquitoes for about 20 seconds then cleared up.
Truck seems to be running strong. Turbo doesn't seem to have any play side to side or in and out(according to Baltimore Performance Diesel who I don't necessarily trust at all [ I will explain my reasoning on that some other time, but let's just say, one of the reasons involves a rear main seal diagnosis... I digress] but I assume they are correct on that, I haven't looked myself. So what are some other possible answers, rings I would think would be fairly constant but I could be wrong there.
Ford 6.0L Power Stroke Diesel :: 2003 F350 - Rumbling At Highway Speeds
2003 f-350 6.0 4wd dual rear wheels
4 inch superlift suspension lift, dual shock steering Stabilizer
33 inch wheels.
4 inch turbo back exhaust
Other than that it's really bone stock
Here's what's going on. In 2wd, between 55mph and 62ish mph, once I hit a constant speed, a rumble beneath my feet emerges. If I either speed up or slow down, it immediately goes away.
Does the same thing in 4wd high.
I can eliminate front drive shaft and u joints seeing as they shouldn't be turning while in 2wd. I did notice that when I push up or side to side motion in the front drive shaft, there is a click and a bit of motion. Is that normal? Just a side thought.
When i take off there's a bit of vibration from the rear half of the truck, but I've isolated that to the center support bearing. With all this being said, none of these symptoms were around before I lifted it.
Ford 6.0L Power Stroke Diesel :: 2003 F350 Shakes At Highway Speeds
Have a 03 f350 with the 6.0 have been experiencing very harsh shaking problems. This only happens at highway speeds 55-60 any other speed is smooth as can be weather it's 25-95 mph. The weird part is that it only shakes when the truck shifts into overdrive and it shakes bad and if you lay into it like you were gonna pass someone it stops then shifts back into overdrive and shakes again.
View 6 RepliesPhaeton :: Surging Of Engine / Momentary Loss Of Power At Normal Highway Operating Speeds
The primary electric fuel pump in the fuel tank of my 2004 W12 failed last month, shortly after I had set out on a cross-Canada trip from Vancouver Island to Toronto. The whole process of diagnosing and identifying the cause of the problem, mitigating it so that I could continue the trip, and finally replacing the fuel pump was kind of complex, so, here's the write-up.
The problem presented itself as a surging of the engine - a momentary loss of power - at normal highway operating speeds. The onset was progressive, but it didn't take very long - only about 60 miles of driving - from the first little cough of the engine until total failure of the pump. The first indication was failure of the car to maintain speed (while on cruise control) when climbing hills. That progressed to failure to maintain speed on flat surfaces, and finally led to the car coasting to a stop, engine stalled, at the side of the road.
I soon learned that if I floored the accelerator pedal and held it against the floor, the car would cough and burp for a few seconds, then take off like a rocket. So, for the next 40 miles, I coaxed the car into the next city by flooring it, accelerating to about 80 MPH, then coasting until the speed dropped to 20 MPH, and flooring it once again and accelerating to 80 MPH. Fortunately, I was on a remote road with few other cars, and no police.
I checked the fuses for the two fuel pumps - fuses 34 and 35 in panel C (above the left battery), and they were both OK.
The next day, I visited a VW dealer in the Canadian Rocky Mountains, and together with the parts manager and one of the technicians, we looked at the Self-Study Guides (SSGs) for the Phaeton, and looked at wiring diagrams. Eventually, we came to a tentative conclusion that the primary electric fuel pump in the fuel tank had failed. The SSGs stated that the primary electric fuel pump (the pump on the right side of the car) operates all the time, and the secondary electric fuel pump (the pump on the left side of the car) only operates during starting and during 'periods of high demand'. That made sense to us - the car started fine, and worked OK when the accelerator pedal was held to the floor (high demand). It just didn't work worth a darn at any other time... the engine would stall, or, the car would not accelerate at all.
Here are two illustrations taken from the SSGs that describe how the fuel delivery system works. The first image is taken from the 'Phaeton Overview' SSG, which applies to all vehicles. The second image is taken from the W12 engine SSG. I kind of suspect that all the Phaetons operate in the same way, regardless of engine, because the fuel tank in all the Phaetons has the same shape - two lower lobes, which means two pumps are required.
Descriptions from the SSGs
I think that there may be an error in the description above. My experience suggests that the right hand pump (identified as G6, above) is the primary pump, and the left hand pump (identified as G23) is the one that switches on during starting and periods of high demand. Note also how the identification of G6 and G23 in the illustration above is reversed from what is shown in the illustration below. I believe that the text and illustration below is correct, and the text and illustration above is incorrect.
The 'effects of failure' in the description above would, I believe, make sense if it was the left-hand pump that failed. In my case, the right hand pump failed, and the effects of failure that I experienced were as I set them out in the beginning paragraphs of this post - quite different from the 'effects of failure' of the left hand pump that are described in the SSG above.
After coming to the tentative diagnosis that the primary electric fuel pump (the right hand pump) had failed, we checked the parts stock status in North America. There was one pump in stock, but it was in the United States, and being that it was a Thursday, the pump could not be delivered before the following Tuesday. I didn't want to spend that much time waiting for it, so, we started thinking about other possible solutions.
If we could somehow get the secondary electric fuel pump - the pump on the left side of the car that only operated during starting and heavy demand - to operate, that just might put me back on the road again. So, I removed the plastic cover from the small relay that operates the secondary pump, and wrapped a rubber band around the relay, thus keeping the relay in the closed position. A short test drive proved that this solution worked just fine, the car once again operated normally. The only "problem" was that the last 25% of the fuel in the tank would be unusable, because that fuel would be left behind in the right-hand lobe of the tank - the lobe with the defective primary fuel pump.
Electric Fuel Pump Relays
Here is an illustration from the Phaeton wiring diagrams identifying the various relays above the left battery.
Here you can see the two relays for the electric fuel pumps. They are identical part numbers.
Here you can see the relay for the secondary electric fuel pump, with a rubber band wrapped around it to keep it continually closed.
Aside from the loss of use of the last 25% of the fuel in the fuel tank, the car worked just fine with the secondary electric fuel pump running all the time. There were no problems noted even under heavy acceleration. It was, however, necessary to physically remove the rubber-banded relay from its position in the relay panel whenever the car was shut down for more than half a hour. The power to this relay comes from Terminal 30 (battery direct) - it is not switched on and off with the ignition as Terminal 15 power is. This meant that if the rubber-banded relay was left in position overnight, the left hand battery would totally discharge, because the fuel pump would operate continuously all night. I discovered this the morning after the first night...
So, for the next 8 days, I drove across Canada, removing the relay each night and replacing it each morning. I didn't bother to remove it when I stopped for meals or fuel. The rest of the 3,000 mile trip was uneventful - except once, when I let the fuel tank run down a bit too close to the 1/4 full mark, and the car began surging again because the left hand lobe of the fuel tank (with the functional secondary pump) had emptied out. That was a close call, but I managed to get to a gas station and refuel.
After arriving in Toronto, I called the parts staff at my home VW dealer and ordered a new primary electric fuel pump. I discovered that the left and right hand pumps are slightly different (the various hoses coming out of the pumps are different), and I also discovered that a pump costs about $400. The parts staff suggested I order two seals (one for each side of the tank), because I would have to remove both the right and left fuel tank covers to change the right pump. The seals were not expensive.
Here are two pictures that illustrate where the pumps sit in each lobe of the fuel tank. Note the fuel filler port on the left side of the pictures (as we know, it is on the right side of the car) for orientation.
Phaeton Fuel Tank, showing pumps
Fuel Pump Access Panels
Below is a picture that shows where the access panels to the two fuel pumps are. It's easy to get to these access panels, just remove the carpeted panel from the floor of the trunk.
Here's a close-up of the right side (primary) electric fuel pump access panel.
The instructions (from the VW Repair Manual, or the ELSA / ErWin system) for replacing the fuel pump are quite well written. The repair manual suggests that the fuel tank be drained before replacing a pump. I didn't want to drain the tank, so, I ran the fuel level down as low as I dared (remembering that 1/4 full is effectively 'empty' with a failed primary pump). That proved to be adequate.
There are a heck of a lot of steps involved in disconnecting all the hoses and loosening the various components before the pump can be removed. I strongly suggest that anyone attempting this task have a printed set of instructions before starting disassembly.
The fuel pump has quite a few hoses and connections on it, but fortunately, each connector is unique in design, thus it is not possible to hook things up the wrong way when installing the new pump. It is possible to 'lose' a hose inside the tank... for this reason, I attached a small piece of string to each hose I disconnected from the pump.
The process goes more or less like this:
1) Remove the two 404 relays, to ensure no power is sent to either fuel pump.
2) Lift the rubber cover, and remove the electrical connections from both pumps (left and right).
3) Using a special tool, lift up the three fasteners that hold the cap over top of the access panel (these are NOT threaded fasteners!)
Here is a side view of the three fasteners that hold the plastic cap in place - they are friction fit, not threaded.
4) Now you have a clear view of the access panel. It will probably be dusty and rusty, and should be vacuumed clean before proceeding, to prevent crap from falling into the fuel tank when the cap is removed. The rust is due to condensation forming on the cold metal part whenever the car is filled with cold fuel from an underground storage tank.
5) A special VW tool is used to remove the locking ring from the access panel.
6) After removing the locking ring, I buffed it up with a wire brush to remove surface corrosion.
7) The plastic access cap can now be lifted. There are two electrical connectors on each fuel pump, but three possible fittings on the plastic cap. Fortunately, the three fittings are keyed differently.
8) This is what you see inside the tank after removing the plastic cap.
9) After following all the detailed instructions for disconnecting and stowing hoses, disconnecting the fuel measurement probe from the pump housing, etc., it is possible to lift the pump out. It will be full of fuel.
10) The old and new pumps, side by side. I was very surprised at the amount of crap that was trapped in the filter screen at the bottom of the pump. The car only has 60,000 miles on it, and I have always used premium fuel in it.
11) I was also a bit surprised at the discolouration of the pump components. Below you can see the old and new pumps side by side.
12) It is necessary to get access to the opposite side (in this case, the left side) fuel pump, because hoses from each pump travel horizontally across the tank and connect to the other pump.
13) Here you can see a new hose from the right side pump connecting into a T fitting above the left side pump. It is easy to thread this hose across the top of the inside of the tank.
14) As mentioned earlier, there are three possible fittings on the base of each plastic cap, but only two connectors within the fuel tank. Everything is keyed, thus improper assembly is not possible.
Once the new pump has been installed, the hoses connected, and the fuel measuring probe reset into the side of the new pump, re-assembly of everything is quite straightforward. I replaced the rubber ring around the access panel opening on each side of the tank, and I also buffed up the locking rings using a wire brush (to remove corrosion) on each side.
It was not a pleasant job - your hands get covered in fuel, and there are some hazards associated with working on an open fuel tank with vapour escaping, but it is not a particularly difficult job. It is time-consuming, though.
Ford 6.7L Power Stroke Diesel :: 2016 F250 - Wind Noise / Vibration At Highway Speeds
Since day one my 2016 F250 occasionally has a reed sounding vibration at highways speeds near the passenger side occupant handle on the windshield pillar. Talked to a service advisor at the dealer about it, what it could be, so this must not be a common problem . The issue is intermittent and can not be reproduced on demand. I tried blowing compressed air all around the area of the Windshield to see if I could reproduce the sound in a shop setting, but no luck. Only thing in common with this noise is 75+ MPH during a rather windy day. I'm a little reluctant to drop it off at the dealer since intermittent problems are hard to diagnose.
YouTube...
Ford 7.3L Power Stroke (1999-2003) :: Low Power / Surging When Going Down The Road
I have a late '99. It's been weak all summer. Took it to the dealership. They put it on the computer and said the only problem was bad injectors. Specifically #8. I replaced them all. It's still weak and now is starting to surge going down the road. I have my suspicions but I'm not a mechanic.
View 14 RepliesFord 7.3L Power Stroke (1999-2003) :: Surging At Light Throttle And Low RPM
I have a '01 7.3 Excursion 2WD. 220,000 miles. It has a 4" exhaust, K&N filter and Edge Reprogrammer set on emission illegal. It gets the best fuel economy and moves out very well for 8000 lbs. Recently, I started to feel a surge while making light throttle acceleration. For example, round a corner at 35 and try to gently resume the 45 Speed limit. It begins to accelerate and then cuts out or surges, sometimes several times. If I lay into it, it responds fine. I have serviced the air filter, the fuel filter, use synthetic Amsoil. I did notice a slight improvement after the service. Less frequent cutting out or surging. I also was in an area where Bio diesel is readily available. I added almost a full tank of B10 Bio and it seemed to work. Changed the fuel filter just after.
It has been cold for NC. This morning it was +14 when I started the truck. It seemed to finally catch on maybe 2 cylinders with lots o' white/ blue smoke. It cleared out in a few minutes and seemed to be hitting on all 8, or at least 7. Once it warmed up, it's fine. But I had the codes p0672, p0674, p0676, p0678. My question is: Is there a common thread in the fact that it appears that I lost 4 glow plugs on the same bank?
One arm chair quarter back's response to the surging, is that the under valve cover injector wiring harness may be breaking down, especially since the truck has 220,000 and the valve covers have never been off. I have a fresh turbo with the good wheel sitting ready. I have just been too lazy to swap it out. Would a fresh set of injectors be a wise choice, when I swap over?
Ford 6.0L Power Stroke Diesel :: Surging Idle After Long Highway Trips?
A few weeks ago i had a surging idle issue very intermittently, and it went away for a while so i stopped thinking about it. Just got back from a weekend in vermont, about 130 miles each way, and i noticed as soon as i got to vermont and came to a stop sign it was surging, and when i just got home it was surging again. Why would this have picked back up after long stretches of running for a while? Runs great as far as i know, just have this surging idle for some reason.
View 14 RepliesFord 7.3L Power Stroke (1999-2003) :: Surging During Warm Up And Some Low RPM Hesitation - No Start
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.
Ford 7.3L Power Stroke (1999-2003) :: 2002 F250 - Surging Between 35 - 50 MPH And When Coasting At About 60
Ran torque for the first time on my f250, I used it for diagnostics to see if i can find out whats causing the surging. At a red light sitting idle it shows my icp at 705psi seems high to me? I'm running a dp tuner, it was set at stock for this run. It starts surging between 35-50mph and when coasting at about 60mph, surges during light throttle or maintaining throttle at low speeds. If i go about 70mph and up it runs like a champ. Ive changed the tps(entire pedal assembly), uvcg connectors, icp and pigtail. No CEL comes on, torque shows ipr is good, working on hpop pid. I just bought the truck last month and haven't been able to enjoy it much since it started doing this. ...
View 14 RepliesFord Super Duty (1999-2016) :: 2003 F250 - Moaning Noise From Front End At Highway Speeds
I noticed a moaning from the front end a few weeks back and it seems to be slowly getting a little worse. It is only noticeable when I'm accelerating or maintain speed, but as soon as I let off the accelerator and start to decelerate, it goes away. Sometimes, when the truck hasn't been driven for at least a couple hours, I pull away and there is a really noticeable sort of "clunk clunk clunk" but then it goes away and it just moans. I can also hear some noise from the front end at highway speeds, but of course it is hard to hear much else other than engine and road noise from the cab. It's a 2003 F250 with a 7.3 and four wheel drive.
View 8 RepliesFord 7.3L Power Stroke (1999-2003) :: Idle Surging / RPMs Will Drop By 300 Or 400 For A Few Seconds
My '03 7.3 is "surging" on idle. When warmed up, and idling, the RPMs will drop by 300 or 400 for a few seconds and then will correct and shoot back up. It cycles like this (every 5 seconds-ish) continually . I just put in a new IDM and checked the UVCH - is there a separate idle control mechanism that I need to have a look at? (2003, 7.3, 214K, stock).
View 14 RepliesFord 7.3L Power Stroke (1999-2003) :: F250 Surging - Running Rough - Dies?
I have a 99 f-250 with about 250k miles. Truck is completely stock. It recently has developed a problem where when I start it in the mornings it surges at idle, 200 rpm or so. Sometimes it tries to die and did once but started back up. When driving it continues to rev itself up and is jerky. It runs rough and sounds like it could be missing on a cylinder. At other times it runs fine just like normal. Yesterday morning it started with these symptoms so I put in a new ford CPS. It ran great for about 100 miles that afternoon. This morning it started back with the same symptoms. The SES light stayed on longer than normal when I started it, but it went off. I don't have a scanner.
I thought it might be water in the fuel because this started the day after I filled it from my transfer tank. But the water in fuel light has never came on. I put a new fuel filter on it but it made no difference. Have pulled filter three times looking for water but never found a drop. Also pulled several buckets from the bottom of my transfer tank but found no water there either. Where to look next?