Ford F-150 - 1997-2003 :: 2003 - Got Code U1262 - Random Misfire?

I have a 03 F150 with a bi-fuel 5.4 engine an it has 195000 miles. I have had trouble for some time now with misfires. I bought the truck in october of 2011 with 125000 miles and replaced all the coils and spark plugs because it was misfiring badly will running on CNG. It was fine on gasoline and never had any codes. After I replaced the plugs and coils it ran fine on CNG and gasoline.

This summer 2013 it began missing badly at highway speeds only when running on CNG. If I accelerated the miss would go away until I was light on the throttle again.I checked the misfire count and found the bad cylinder and replaced a coil. Then a day later same thing on another cylinder. I swapped a coil from another cylinder and problem went away for a day. Eventually I chased the misfire around all the cylinders on the engine until I had ended up either replacing a spark plug or swapping a coil on all the cylinders. And I still had a misfire. It seemed to be worse on days with temperatures above 90 degrees. Eventually I got it to stop misfiring.

So now 5 months later I am back again with a misfire. This time it is misfiring on both gasoline and CNG and under any throttle conditions, except coasting. I have no codes. And the misfire monitor is sending me around the engine again. I have replaced a spark plug in two cylinders and swapped 4 coils.
I'm ready to buy all new coils, but I want to be sure that it is not a waste of money since the old ones only have 70000 miles on them.
Two days ago I had the misfire monitor saying #4 in the evening and the next day without me having done any work on it it was saying #6. Later that same day it said #7 and I still hadn't done anything other than drive the truck.

I checked the connections at the firewall on the drivers side with the three large plugs that are held in with a 10mm bolt, they looked fine, no corrosion or burnt pins. I checked the connection at the ACFM which also looks good. I will check the connection at the PCM in the next day or so.

Some other problems that may be contributing:
1. I occasionally get a U1262 code (scp fault)
2. Sometimes when I check the misfire monitor it only shows 7 cylinders, sometime 9 cylinders. I am using an Innova 3160 scanner.
3. I have either a leaking valve cover gasket or leaking head gasket, because I have oil dripping from the rear bottom corner of the passenger side cylinder head right above the exhaust pipe.

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Ford F-150 - 1997-2003 :: Truck Has Random Misfire Code

I was involved in a light accident over the weekend. I was hit in the rear by a Prius which didn't do body damage except for the 7 blade harness for my trailer towing. But, now the truck has a random misfire code. You can feel the truck jerk when you go up any grade. We changed the fuel filter and dumped in some cleaner already. One guy says its fuel and one thinks its coils. It is a 2003 F150 extended cab 5.4 with a nearly new motor. The truck has about 175xxx on it and I have had it for about 40xxx. I have not changed coils. We did check the inertia switch on the passenger side and it was not tripped.

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Ford F-150 - 1997-2003 :: 1999 - Random Misfire While Driving On The Bad Alternator

I have a 99 F150 4x4 with 5.4 Triton, 99xxx miles. I was towing my boat when the regulator in my alternator went bad. I drove the truck with the voltage being sporadic for about 10 miles until I could get to a parts store. While driving on the bad alternator, I started noticing a misfire. I replaced the alternator, battery and DPFE. I still have the misfire....but here is the kicker. The misfire only happens when the truck reaches operating temperature. Which, in my limited knowledge, eliminates a fouled plug, COP, bad injector and a vacuum leak. I've got no check engine light so I can't pull a code. The only thing I can think of is to clean the EGR?

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Ford F-150 - 1997-2003 :: Random Delayed Start When Truck Is Cold

Not all the time, but I've noticed it after the truck has been driven - shut off - then started again within a few min period. When truck is cold or has been sitting for an extended it starts no problem. By "delayed" I mean once I try to start the truck it takes a sec or two longer than normal before it cranks. Then when it does start it will idle very low for a sec or two then pick up and act normal.

So far I've done this to remedy it:
- new fuel filter
- new air filter
- cleaned MAF sensor
- cleaned throttle body
- seafoam thru vac hose

Only thing else I suspect is weak fuel pump but looks like it was act up all the time not just when the truck is started back to back. Truck has good power when running, I did a couple short blasts up to 80mph and everything was fine.

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Ford F-150 - 1997-2003 :: Cylinder 2 Misfire / Replaced COP And Now Stuttering Start

I have a 2003 f150 that has a history of misfiring on one side. It started with a misfire on #1, then #4, and finally #2. I replaced all 8 plugs last year and each COP as it gave the misfire code over the course of the last 3 years. My latest run in was with #2, and I replaced the COP today and took it for a test drive. It was running pretty rough at idle, which I assumed was from disconnecting the battery, but then the stuttering started but it felt a little different than the standard misfire that usually didnt pop up until 40-50mph.

This stutter was more constant, and it also let up when I would coast. I only took it for a 4-6mile test drive and toward the end, the "Service Engine Soon" light started blinking and then went off by the time I got home. I parked it and noticed quite a lot of crackling noises that seemed more than normal, but it was a hot day and I was pissed that I didnt fix it so I cant say for certain if it was out of the norm or not, but it seemed louder and more frequent. Then I got to worrying about my cats going bad.

So, my questions are:
Could I have done something wrong when changing the COP?
What can the flashing "Service Engine Soon" light mean? Ive only seen a solid one before.
Should I be worried about the cat going bad since all the issues have been on that one side?
What should I do next?

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Ford F-150 - 1997-2003 :: Rough Idle At Start For About 30 Seconds - Cylinder 1 Misfire

2000 5.4l lariat. My cylinder 1 for 2 years has been poping p0301code and has a rough idle at start for about 30 seconds. It also has a little white smoke for that 30seconds. new cop, new spark plug, new spark plug pig tail, swapped injectors to different cylinders multiple times to change code no luck. Compression dry and wet are at 200 and all cylinders are within10%. I had a dorman intake manifold installed 4 years ago and the code came a few years after. Im thinking intake manifold gasket is bad between cylinder 1 and the heater bypass tube allowing coolant to slowly leak down into the cylinder causing my rough start. I looked through the injector hole but could not tell. With all the info I have given is there any other places or things that it could be before I do a gasket replacement or is all my tests leading to the intake manifold gasket...

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Malibu :: 1997 Chevy Misfire At Random Times And When Under Heavy Loads

I have a 97 Chevy Malibu V6 3.1L with 92k miles on it, a couple weeks ago i started getting a misfire issue. The car would start to misfire when under heavy load such as accelerating up a hill. The local auto parts store diagnosed it with code P0302(cylinder #2 misfire). I started by replacing all of my spark plugs(ACDelco Platnum) and wires. This seemed to fix the issue for a day or so, after that the misfire worsened. I would misfire at random times and when under heavy loads. This caused my transmission to keep shifting up and down followed by the all to familiar hot/melted plastic smell of overheated transmission fluid. This continued on for a few days as it got worse.

The car than started to misfire heavily all the time. I took the car to another auto store and it pulled up codes for Random/multiple misfire. I then took my car to a mechanic for a full diagnostic, their computer said their was a misfire on cylinder #1, as-well as a bad spark plug wire on #1( He found this by getting shocked while wiggling the wires on the coil pack) and told me to replace the bad wire. I replaced all wires again and the problem remained. i took it back up for re-diagnosis and they then said it was a bad coil pack. I replaced the coil packs and the problem still remains.

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Dodge - Neon :: 1997 - Check Engine Light Has Been On And Causing Random Misfire

I have a 1997 Dodge Neon with about 153,XXX miles on it. My check engine light has been on and i know that is caused by a random misfire. But more recently i went to start my car and it started but ran for less then 10 seconds and died. I tried to start it again and it wanted to but wouldnt make the final step i guess. We checked my spark plugs and i had oil sitting in 3 of the 4 there are. We have tried starting it again after cleaning the oil out and it started on the first try, I am just afraid of messing anything else up so until we figure out why it did this to begin with the vehicle is off limits. My Fiance said we need to replace the spark plugs and a gasket.

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Golf IV / Jetta IV :: No Start - Random Misfire / Stalling And Bad MPG

Well first the exact car I have. 99.5 Jetta 2.0 AEG. It all started with one loud backfire with a stall at a stop light while in neutral. After that it was random stalling and jerking while driving. So I checked my everything and all seemed well. I replaced spark plugs because they where fouled and nasty. Cables are good. They're near new and tested them with a multimeter. Next I checked my injectors and they are surprisingly very clean.

I had also ran seafoam prior to these problems a few weeks before it all started. Next step was new fuel filter. Old one was nasty and black stuff dripped out. That didn't work. So I checked for vacuum leaks with throttle body cleaner. Nothing. Visually threre is nothing wrong under the hood. So today I changed the fuel pump. Went for a test drive all seemed well. Can out of the bank. Then it won't start. So I wait like normally. And it normally gets me home. Nothing. Will sometimes start but if I'm not holding the gas it dies. I don't know what to do. My only other thing I can think of is the coil pack.

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Chevrolet - Montecarlo :: 2003 - High RPM Random Misfire

Here's the deal with this car i just did head gasket, valve job, all new intake gaskets and spark plugs. Car idles fine and mid throttles fine but with high throttle it wont shift and flashes the random misfire light p0300 it seems to run out of power. I've heard everything from maf sensors to ignition coils and wires. i was just wonder a good place to start and good test to do. I have most testing equipment including scan tool so i can ride with it. o and all cylinders compression tested above 150.....

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Nissan - Xterra :: 2003 - Random Misfire / Bog Down When Accelerating

We recently replaced the engine in my 2003 Nissan Xterra and since then we have had a problem with misfires. When accelerating it will periodically. Bog down and the car runs so rough the whole thing shakes. Then it rapidly accelerates and smooths out. Then the check engine light flashes. We have replaced everything not nailed down-plugs, wires, knock, crankshaft and mass flow sensors and on and on.

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Golf IV R32 :: CEL Start To Blink Then Stay On - Random / Multiple Cylinder Misfire Detected

I was driving the car normal with no problem. Got to a red light stop an as I was coming out of the red light the car started to hesitate a bit. So I start to drive home as I was driving home my check engine start to blink and then it stay on. When I got home and park the car I shut off ,then start it up again then the check engine light was off but the hesitation was still there. Then I got my computer and got the vagcom and got this code :

16684-random/multiple cylinder misfire detected
P0300-008- implausible signal

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Chevrolet - Avalanche :: 2003 - P0300 Code / Multiple Or Random Misfire?

My 03 Chev Avalanche is giving me a P0300 code (multiple or random misfire). With no distributor or individual coil is this something I can fix myself or is it shop time?

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Ford F-150 - 1997-2003 :: Random Pinging Noise From Under The Truck

I just picked up a 1999 F150 5.4 with around 19k miles on it. Truck is in mint condition, stored in a heated garage since new. Before we made the deal I checked everything out pretty well including checking all the fluids, test drive, other usual stuff and didn't notice anything out of the ordinary. However, today I went for a short ride with the windows down I noticed a random pinging noise from under the truck. At first I thought it was a few small rocks bouncing off something metal under the truck, however it continued to do it randomly for the next 5 minutes. I would say I hear a ping every 15-20 seconds randomly. Doesn't matter if it's idling or under load, happens about the same either way. Aside from this, truck starts and rungs great and no error or warning lights have kicked on.

When I got home I started the truck back up and climbed under to see what it was. I found that the noise is coming from the exhaust system, mostly heard at the catalytic convertor. It resembles the metal expanding kind of ping, but I think its actually originating at the engine and the noise is just carrying through the exhaust system. I then went back to the engine bay and could hear the same random ping, just much quieter. I don't know the condition of the fuel, but based on the low miles I haven't ruled out a bad tank of gas. Only other issue with the truck is there is a bit of rust and corrosion on the inside of the exhaust tips and up into the exhaust pipe. They are still shiny and silver on the outside, just a little rust buildup on the interior of the exhaust. Hoping it's just the last 1' or so that is rusted

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Ford F-150 - 1997-2003 :: 2000 - Speedometer / Gauges Going In And Out At Random

I recently purchased a 2000 F150 Regular Cab Work Series with the 4.2 V6 4x4 and an automatic transmission. It has what seems to be an electrical issue where the speedometer and gauges come in and out seemingly at random. All of my fuses are good with the exception of Fuse 1 in the fuse box under the steering wheel, which will blow every time I put a new one in. It seems like there is a short in the wiring for the radio? However Fuse 1 is supposed to control only the audio, and I'm not sure why that would be an issue with the gauges.

When they come on, everything seems to work just fine. Also, even when they go out and I have the headlights on, both the gauges and the car stereo will be backlit with the green glow.

When I turn put the key in the run position, the gauges will come on and remain on for a random amount of time after I start the engine, then will go out and come on at random. When the gauges go out so will my check engine light (code P0460).

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Ford F-150 - 1997-2003 :: ABS Light Comes On And Off At Random - Code C1185

My abs light comes on with the code above and im looking to fix it. No I don't want to buy a new abs module. Code C1185 - Car Forums and Automotive Chat the only thing i could find remotely close is from this link for a 2000 ford windstar. Need to just comfirm that there is a chance that resoldering the joints would work in fixing the problem that would be great. The light comes on and off at random. 2001 f-150 lariat 4x4.

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Ford F-150 - 1997-2003 :: 2001 - Sputtering At Random Times

It started sputtering at random times a few days ago and the check engine light came on. The two codes are p0401 (blocked egr system) and p0402 (egr valve stuck open). It seems to do it most when it's cold but some days it'll do it non stop.

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Dodge - Durango :: 2003 - Code P0300 Random Misfire / Engine Running Rough

Just started getting a p0300 random misfire code on the durango a couple days ago. pretty sure it isn't moisture related since it started on a nice sunny day. it was running pretty rough so it was obvious that it was misfiring. I changed the plugs since it was about time anyway, and they needed it and I cleared the codes. new plugs (put in the oem champion copper plugs) didn't make the problem go away. The engine still ran rough and the code came back. 2 of the plugs looked like they may have been fouling a little bit. they were a fair bit blacker than the rest of the plugs. I went ahead and changed the coils on those two cylinders and reset the codes again. Still runs rough and the p0300 came back. where do I go from here? I am not getting any specific cylinder codes so it makes sense to me that it isn't one or two cylinders not getting spark. 2003 durango 4.7 ....

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Ford - F250 :: 2003 - Refuses To Start At Random

On Saturday afternoon of Labor Day weekend my dad's 2003 Ford F250 "died" in the parking lot at my work. It had been running fine all morning, but then I stopped by work, and when I went to leave it barely started, ran for a few seconds at a rough idle (presumably on whatever fuel was already in the system), then died and would not restart. Turned over strongly (new battery a few months ago) but no ignition. Checked the fuses and fuel pump interrupt switch, but everything was fine. Had just put 15 gallons of gas in earlier in the week so I "knew" that wasn't the problem.

When I had it towed to my mechanic. He didn't get a chance to look at it until the weekend, and called me Monday to say that it started just fine for him all weekend, but it could use some gas. I knew I should still have 12-15 gallons in there, so we came to the conclusion that someone had siphoned my gas. Monday night I picked it up, feeling dumb for not checking that more carefully, and drove to the gas station. Sure enough, the gauge registered "E" and the low fuel light was illuminated. Put in 8 gallons. Started the truck and the gauge popped up to 3/4 tank.

8 gallons is NOT 3/4 of a 32 gallon tank. It's 1/4. The original fuel was still in there! On the way home from the gas station I stopped by work to load up the lumber I had to leave there the first time it died and--you guessed it--died like before. This time the gauge definitely read 3/4 tank with the key on, so the problem was not low fuel. I didn't want to pay to have it towed again, so my mechanic said he'd come look at it when he got time. I tried to start it a few times throughout the week and on Saturday it started right up and ran strong all the way to his shop, where it continued to start every time we tried it. It could be the crank position sensor, but the confusing part is the low fuel indication.

Could the fuel gauge have gotten stuck when the truck was was pulled up on the rollback? And would it have stayed like that all the way to the gas station? I also don't think it's the fuel pump because it runs so strongly when it does start. The second time it died the gauge still read 3/4 tank so I don't think it's related. The mechanic can't fix a problem he can't reproduce, and I really need the truck to pull my 3,000lb landscape trailer on the weekends. My 2000 Wrangler isn't exactly ideal for the job! Oh yeah, the truck is stock, 5.4L gas, off-road package, tow package, extended cab, long box, auto trans, 85K miles.

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