Triton V10 misfire the million dollar question

[LVFISHN]

Originally Posted by mrt_1111

Did your mechanic hook up a scanner on it to give a place to start troubleshooting?

He did. He said it was throwing codes of a misfire. Check engine light was showing some kind of o2 sensor. I don't remember if he said it was just one cylinder or several. I have read if it throws the code for several, especially on the same side that it could be the injectors. Does that sound correct?

[ransil]

Pull codes
Check fuel pressure
Ford coils are recommended, aftermarket are suspect codes should point to a coil or a bank to narrow it down

[LVFISHN]

Looking at the invoice, this is what was done:
Fuel system cleaning wynn's ( not sure what wynn's means)
10 spark plugs changed
10 coil boots changed
Fuel filter changed
1 ignition coil

I am assuming since just one coil was changed it was the one throwing the code.
Not quit sure why they changed just the boots.
I pulled the engine cover and sure enough they only changed one coil. It has no brand on it. The others say motorcraft. The fuel filter looks new as well as the boots.
Gonna take it this week and see what code it's throwing. The coil they replaced is the #3 cylinder. What code should I expect if it is #3 again?

[ransil]

Not sure what code, pull them then go from there if it points to a specific cylinder then swap that coil with a different one and see if the code moves.

[TeJay]

The worst thing you can do is to chase your tail. All of this stuff can be checked and tested. Why they changed just one coil is plane stupid IMO. I've read many posts on here that have reported when it's time for one coil to start misfiring there are enough miles and age on all of them to start doing the same thing.

Do some searching on this forum. Several have bought aftermarket coils a lot cheaper than the Ford dealer ones and they have worked just fine. I don't remember the brand or where they got them but you should be able to find the thread.

Injectors will fail individually unless something is happening with the CPU. Then it's possible to have a bank of them fail. Subford knows that stuff well.

Wynn's is a liquid they poured into the intake to clean the carbon.

Now test, test, test. Check the codes and get the coils working. Check the fuel pressure and remedy that situation if it's present.

I'm not to impressed with your mechanic. Low compression won't cause a misfire. That's ignition which is not effected by a cylinder with low compression. And again that is easily checked. It was just a guy grabbing at straws because he didn't diagnose before he started changing parts.
The V-10 is notorious for misfires when it has the necessary age and miles. It's almost always defective ignition coils. Misfiring p a hill (under load) is the classic symptom of defective coils.

Try this link for coils. http://www.jegs.com/vpt/Accel/Ignition+Coil

[rjsupersonic]

Double check the fuel filter, they may not have changed it. The fuel tank may have rust in it and after you drove it sucked it back into the fuel filter. A lack of fuel will cause a misfire.

[TeJay]

Here's another point that I forgot earlier concerning your missing. If it is a plugged fuel filter not able to keep up with higher fuel demands it is not as likely to miss under load. Under load missing is the result of coils putting out more voltage. If it were fuel it would miss under other times of high demand like higher speeds and on level ground. If it only misses under load that sure points to weak or defective coils. At least that's MHO.

[Skripo]

Originally Posted by TeJay

The worst thing you can do is to chase your tail. All of this stuff can be checked and tested. Why they changed just one coil is plane stupid IMO. I've read many posts on here that have reported when it's time for one coil to start misfiring there are enough miles and age on all of them to start doing the same thing.

Do some searching on this forum. Several have bought aftermarket coils a lot cheaper than the Ford dealer ones and they have worked just fine. I don't remember the brand or where they got them but you should be able to find the thread.

Injectors will fail individually unless something is happening with the CPU. Then it's possible to have a bank of them fail. Subford knows that stuff well.

Wynn's is a liquid they poured into the intake to clean the carbon.

Now test, test, test. Check the codes and get the coils working. Check the fuel pressure and remedy that situation if it's present.

I'm not to impressed with your mechanic. Low compression won't cause a misfire. That's ignition which is not effected by a cylinder with low compression. And again that is easily checked. It was just a guy grabbing at straws because he didn't diagnose before he started changing parts.
The V-10 is notorious for misfires when it has the necessary age and miles. It's almost always defective ignition coils. Misfiring p a hill (under load) is the classic symptom of defective coils.

Try this link for coils. Accel Ignition Coil | JEGS High Performance

Sorry but that is wrong.

It is common knowledge that a bad cylinder, a bad piston ring, valves that are sticking, leaking, or out of adjustment will affect the amount of air coming into the cylinder, which can cause a misfire.

Google it if you don't believe me.

Everything else is correct.

[TeJay]

It's not that I don't believe you read how this thing happened.

Two hundred mile trip home and 1 misfire.
Tune-UP, tires, fuel filter.
Next trip drove horrible could not climb hills. Stopped then took off again and OK for 5-6 miles then misfiring again. They did change one coil. He also had the filter changed. Yes it could have a lot of rust in the tank and again plugging up the filter.

So yes he needs to re-check the filter. That is easy enough to check and so are defective coils which he said the tech said it was throwing more misfire codes under load.

Many make the mistake by assuming that when a part is changed that the new part is good. That would be true with the fuel filter and it is also true for the coils. As I stated earlier when one COP goes bad they all have been in service for a long time and often the rest will soon follow so don't count them out either. All of these items can be tested to determine if they are working.

I re-read his original post and he did say that it re-started after setting for a few minutes then would start missing again. I guess I missed that part or it didn't register with me. You are correct and I'm wrong it is probably a plugged fuel filter again.

In all my years of working of vehicles I seldom ran into a plugged fuel filter. Many often assumed plugged filter changed them but for me it seldom was.

[spyderRV]

Crud in the tank, eventually clogs fuel pump filter sock. Engine off, crud falls off. Engine runs until sock clogs again. Rinse repeat.........?

[winnie32v]

2001 Winnebago Adventurer, Triton V-10, 45,000 miles.

Had a similar experience about a year or so ago.
Multiple misfires, P0301 - 10 Codes (specific cylinder)with also P0300 (multiple random misfires).

So, lots of trouble shooting with my mechanic.
Replaced fuel filter, checked compression on all cylinders, checked fuel line pressure while driving (especially going up steep hills with toad attached), changed all 10 coils/boots, cleaned mass air flow sensor, had a new air filter recently, also.
At this stage, all tests were OK, but still some random misfires occurred, especially under load.

So, broke down and the thing that was not expected --- replaced the spark plugs, being sure to torque to factory specs (I think about 11-13 lbs, due to aluminum heads and ~3 threads holding plug in, etc. etc.). I hope your mechanic was/is familiar with the lower torque spec for this model of V-10--if not, there is a potential for thread stripping and plug blowout. Please check on this before you put on too many miles.

Took motor home with toad attached on a 100 mile trip, up three of the steepest hills in my area and the V-10 ran PERFECT!!!!!
NO MISFIRES and more power and response than I've ever had before.

What I found out from this forum: Although the Ford Tech told me NOT TO WORRY about the plugs for 100,000 miles, I find out that the plugs can become "degraded" internally and will not transfer the spark sufficiently---so a misfire occurs. In the "old days" we would look at a plug and determine if it was good or not!! I was sure to use only the factory spec plugs (Motorcraft only) which had the nickel coated threads so they didn't corrode in the aluminum heads (another story).

My problem was solved, my last trip to Florida and back was a pleasure with NO engine misfires and about 1 MPG better gas mileage.

This may help you in your trouble shooting your misfire.
Please keep us informed of your progress.

[rgmiller32]

The first thing I would check on, would be did he install Ford/Motorcraft spark plugs. Having worked on several V-10 engines in emergency vehicles, we found that the Motorcraft plugs worked the best. I know a plug is a plug. The other guys plugs might be made for several different engines with just different bases. The Ford/Motorcraft plugs are made for the Ford application.


The next thing would be to check the coil on plugs. These coils are some what known for getting small cracks and for the windings in them to break down. Again stay with the factory Ford/Motorcraft or a higher quality aftermarket unit. Stay away from the cheaper aftermarket no name types.


Check the fuel system pressure and delivery. If it has sat for a long time the fuel is most likely bad and has attracted water and contamination. Water in the fuel will cause all sorts of problems from rusting of the fuel tank and steel lines, to causing the seals in the injectors drying out. There might also be very fine screen type filters at the injectors that could be catching some of that trash in the fuel system.


Also if the unit sat with very little fuel in it you could have rust and dirt in the tank. Good luck and start with the basics and a engine scan. Keep us posted.

[TeJay]

Another point regarding the reports about plugs. What most don't realize is over the years the output from these newer ignition systems has greatly increased. That's the voltage coming out of the ignition coils. Here's the scenario of what happens. I'll have to guess about the voltages since I don't know what they are on the newer systems but I do know they are higher.

The coils will only put out what is needed to overcome the resistance to jump across the gap at the plug. It will have a lot more in reserve. The old systems required about I think 12,000 or so volts to jump the gap and about 5-7 to maintain the spark. As the gap got wider the voltage went up but the engine still ran just fine.

The older systems also had more places (Secondary (high) voltages) where the system could fail: plug wires, cap & rotor. These were all places where the high voltage could jump to ground. Saw many a burned track inside caps where the voltage would jump to a different plug insert.

That's the exact reason why we have these new systems. The manufacturers had to make systems that would last because of emissions standards and longevity.

With the newer systems the reserve voltage is a lot higher. Probably in the 60,000 or more volts. So on the V-10 with all that extra reserve as poster # 25 (winnie32v) experienced he did all he could but still had misfires until he changed the plugs. What happened??

The system failed because as the demand became greater at the plug tip the system produced more voltage. Enough voltage that eventually as the law of physics will demand the higher output voltage found a different path to ground than across the plug gap and he had misfires.

Poster #26 (rgmiller32) talks (2nd paragraph) of how the new COP coils fail internally. Under load the conditions in the combustion chamber become harsher the voltage increases and you have misfires.

[Johndale]

https://www.ebay.com/itm/172280142878
This site is very good on parts.