That's cool. They are not supposed to as the warranty only goes to the original owner but when you have a history with them they're usually pretty cool to you.
Misfire count
- Thread starter Bain64
- Start date
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Yes. On mine which is an older autoxray 5000 but it seems to be similar to most of the scanners that have the instant moderate during and the information passed just listening the individual code. Every time I clear the codes for check engine light it clears out the misfire counts.
I have the $28 chinese brand coil packs on the way as a test, arriving tomorrow.. But digging into the shop manual a bit more, i'm wondering if my high fuel pressure is what's causing these minor misfires...
Shop manual reasons for P0420/P0430
Anyways back to the fuel pressure, a few months ago when I checked I had 88 psi, shop manual says 48-70 is normal. I need to buy my own gauge so I can check again at will, but it did appear at the time that the regulator is failing open, which accounts for the negative long term fuel trims.
Shop manual reasons for P0420/P0430
- Use of leaded fuel
- Damaged HO2S
- Malfunctioning ECT
- High fuel pressure
- Damaged exhaust manifold
- Damaged catalytic converter
- Oil contamination
- Cylinder misfiring
- Downstream HO2S wires improperly connected
- Damaged exhaust system pipe
- Damaged muffler/tailpipe assembly
- Retarded spark timing
- Leaking fuel injector
Anyways back to the fuel pressure, a few months ago when I checked I had 88 psi, shop manual says 48-70 is normal. I need to buy my own gauge so I can check again at will, but it did appear at the time that the regulator is failing open, which accounts for the negative long term fuel trims.
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You have to be careful about looking at lists that can cause problems. They tend to include every possible thing under the sun that could cause the problems because that's what the name of the list is. You're much better off on forms like this or in some F-150 forums or other Ford forms where you might get more information specific to the engine where people's experiences is much more accurate than those lists.
I don't think I've ever seen 80 psi on a Ford. I don't think I've ever seen that high fuel pressure on any car unless you're pinching off the return line to deadhead the pump to see how high the pressure would go.
I don't think it will cause misfires.
I have built up quite an ear/ feel for it as a lot of people have and can definitely tell an ignition misfire over any other type of misfire.
For the money, the coils are a great test and I'm running several of my cars on them right now and I got eight years out of the first set of eBay ones I bought before I had a single one starts randomly misfire.
What about the plugs? How long have they been in there? I would feel more comfortable about a fresh set of plugs whose gaps have been checked and I tried it a good snug . 052 if we're talking about a 2 valve.
In my entire life I never saw a spark plug go bad oh, just get old or dirty or severely rounded off center electrode and Gap wear. Since 2005 I have seen three spark plugs go bad that were perfectly fine and working great for several thousand miles but we're not old and worn out.
They each cause random misfires or a solid miss once they got up to temperature or at least at certain temperatures.
If a not relatively new and you didn't do them or check the gaps yourself I wouldn't trust them. Just go get some standard single Platinum Motor crafts they are only two or three dollars a piece.
Don't worry about anything more expensive or being up sold at the parts store for this is just a test purpose to get the vehicle running perfect for now.
Then you can find out after the fact that those coils and the standard plugs are great for many thousands of miles and years. At least that's the goal and it has been the case for me.
Many people do not check plugs before they install them and they don't gap them with the obsessive compulsive disorder that I do.
Simply dropping a plug even in the Box can cause damage that can show up as a shortened life or misfires later.
Even if you don't do plugs, clear out the codes and with the new coils check your misfire counts. If you do find a cylinder that gives you missed our counts on more than one scan then suspect that plug. Replace it or do the set. It's just easier for me to go ahead and stick plugs in when I have the coils out.
Let us know. Diagnostics are my favorite thing to do two vehicles in person. Not as much fun over the phone or via internet. I don't exactly love to fix the problems I just like to diagnose.
I don't think I've ever seen 80 psi on a Ford. I don't think I've ever seen that high fuel pressure on any car unless you're pinching off the return line to deadhead the pump to see how high the pressure would go.
I don't think it will cause misfires.
I have built up quite an ear/ feel for it as a lot of people have and can definitely tell an ignition misfire over any other type of misfire.
For the money, the coils are a great test and I'm running several of my cars on them right now and I got eight years out of the first set of eBay ones I bought before I had a single one starts randomly misfire.
What about the plugs? How long have they been in there? I would feel more comfortable about a fresh set of plugs whose gaps have been checked and I tried it a good snug . 052 if we're talking about a 2 valve.
In my entire life I never saw a spark plug go bad oh, just get old or dirty or severely rounded off center electrode and Gap wear. Since 2005 I have seen three spark plugs go bad that were perfectly fine and working great for several thousand miles but we're not old and worn out.
They each cause random misfires or a solid miss once they got up to temperature or at least at certain temperatures.
If a not relatively new and you didn't do them or check the gaps yourself I wouldn't trust them. Just go get some standard single Platinum Motor crafts they are only two or three dollars a piece.
Don't worry about anything more expensive or being up sold at the parts store for this is just a test purpose to get the vehicle running perfect for now.
Then you can find out after the fact that those coils and the standard plugs are great for many thousands of miles and years. At least that's the goal and it has been the case for me.
Many people do not check plugs before they install them and they don't gap them with the obsessive compulsive disorder that I do.
Simply dropping a plug even in the Box can cause damage that can show up as a shortened life or misfires later.
Even if you don't do plugs, clear out the codes and with the new coils check your misfire counts. If you do find a cylinder that gives you missed our counts on more than one scan then suspect that plug. Replace it or do the set. It's just easier for me to go ahead and stick plugs in when I have the coils out.
Let us know. Diagnostics are my favorite thing to do two vehicles in person. Not as much fun over the phone or via internet. I don't exactly love to fix the problems I just like to diagnose.
1955moose
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Bain we warned you about that high pressure over 6 months ago. Why do you ignore it? Your going to burst something with that high of pressure. If your blood pressure was that high, you wouldn't be texting us today. Throw a regulator or whatever causing it. Top running pressures are 28-45 for a 2007 Expedition, I can't remember what year yours is, but 50psi should be highest. I think that Ford chart is wrong, either way your way too high. You'd be the equivalent of a human running 190/130 bp.
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Most of the fuel system will handle 100 PSI even more but for how long? I have squeezed off line and seem them hit a 100-110 but I wouldn't want that being on there all the time.
I would assume that the regulator is the first thing to its back but I've never even heard of one of those making pressures this high.
Without looking at it I wouldn't know if this is a type of regulator you can disassemble or not. I have had good luck taking them apart and clean them and putting them back together.
I still don't think that is causing random misfires though. A fuel injector should be perfectly capable of handling 80 PSI and seal off properly between pulses and fire just fine.
I would assume that the regulator is the first thing to its back but I've never even heard of one of those making pressures this high.
Without looking at it I wouldn't know if this is a type of regulator you can disassemble or not. I have had good luck taking them apart and clean them and putting them back together.
I still don't think that is causing random misfires though. A fuel injector should be perfectly capable of handling 80 PSI and seal off properly between pulses and fire just fine.
It's a 2003. You're absolutely right, it was hard for me to justify when there weren't any other symptoms except high fuel pressure. I've only owned it a year and spent more than 50% of the original purchase price in repairs, and was holding off on what I could.. And at this point I'm pretty sure I need a fuel pump, power steering pump and upper control arms.
The upper psi of 70 listed in the factory shop manual seemed high to me, that was the first time I had ever seen that figure listed.
The new coil packs did not help the misfires.. As an aside, the drivers door window regulator broke last night, and now the wife is encouraging me to start shopping for vehicles. I think I'm going to limp this one along until after the family Disney trip and start looking for a 13-14 Expedition or Yukon/Tahoe... Don't hate me if I move to the dark side (GM)!
1955moose
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Yeah, it sounds like it's time to cut your losses and move along. Sometimes we get lucky with used vehicles, sometimes we take it in the rear. This SUV must have lead a tough life. I've always had best luck with low mileage examples. Takes some looking, but I'd rather log on my own miles. Buying used is always a crap shoot no matter how well you check it out ahead of purchase.
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That sucks. But that's why I said it's worth it for the $27 test. I don't recall if you're able to see mode 6 data after a reset to see if it's really a ignition mess or not?
Of course the computer will say any misfire even if it's an injector and still show it as a misfire but on these engines over nine times out of 10 if it's a misfire it's a plug or a coil.
What are your short and long-term fuel trims? If the fuel pressure is that high it should be running extremely rich. Fuel injectors only have a duty cycle from the ECM. When it starts out with all the learned information cleared, it will be trying to spray the adequate amount of fuel which means it's staying open for the appropriate amount of time. If you double the fuel pressure more fuel gets through. Of course since these cars then are computer-controlled, it will sense the richness and it should start subtracting Fuel and your short and long-term fuel trims.
Does the thing have a noticeable miss or shake at idle in drive with your foot on the brake? It's got to be something simple. Even if you are going to sell it you want to make it run right so you can get top dollar out of it.
I don't believe in ever trading in a vehicle. Bad bad bad bad bad bad bad! I give you nothing nothing nothing nothing nothing nothing nothing.
Well, to be accurate on a vehicle with a fairly higher-value they do give you something but they are ripping anyone off who trades in a vehicle.
They just don't come down as much on the one you're looking to buy and they lowball you on your trade amount anyways. So when I'm talk about replacing a vehicle or selling one and buying another one then I mean it's time to clean up the car fix any little small problems make everything presentable as possible so it will run nicely on a test drive so I can get top dollar.
You can get a fuel pump for that thing for under $100 even if you have to go to a salvage yard or buy a used one on eBay. Takes less than an hour to install the pump so that would at least fix your high fuel pressure.
Of course the computer will say any misfire even if it's an injector and still show it as a misfire but on these engines over nine times out of 10 if it's a misfire it's a plug or a coil.
What are your short and long-term fuel trims? If the fuel pressure is that high it should be running extremely rich. Fuel injectors only have a duty cycle from the ECM. When it starts out with all the learned information cleared, it will be trying to spray the adequate amount of fuel which means it's staying open for the appropriate amount of time. If you double the fuel pressure more fuel gets through. Of course since these cars then are computer-controlled, it will sense the richness and it should start subtracting Fuel and your short and long-term fuel trims.
Does the thing have a noticeable miss or shake at idle in drive with your foot on the brake? It's got to be something simple. Even if you are going to sell it you want to make it run right so you can get top dollar out of it.
I don't believe in ever trading in a vehicle. Bad bad bad bad bad bad bad! I give you nothing nothing nothing nothing nothing nothing nothing.
Well, to be accurate on a vehicle with a fairly higher-value they do give you something but they are ripping anyone off who trades in a vehicle.
They just don't come down as much on the one you're looking to buy and they lowball you on your trade amount anyways. So when I'm talk about replacing a vehicle or selling one and buying another one then I mean it's time to clean up the car fix any little small problems make everything presentable as possible so it will run nicely on a test drive so I can get top dollar.
You can get a fuel pump for that thing for under $100 even if you have to go to a salvage yard or buy a used one on eBay. Takes less than an hour to install the pump so that would at least fix your high fuel pressure.
