OBDII Scanners advice

[dhermesc]

I have a cheap $25 scanner that gives codes when the CEL is on. Looking to step up a bit for one that will go a little deeper - like the issue I have right now. I have a 1999 Ford F250 with the V10 and I am getting a generic random misfire code. I know one (or two) of the COP have gone bad - what scanner would go deep enough to tell which cylinder(s) have the miss fire?

 

[johnnmr]

I've only used snap on scan tools for the last 25 years, no experience with anything else. I buy them used on ebay, use them til I need newer software, then buy another 1.

 

[Butch(OH)]

If you are getting the random misfire code,, 300? I think? then you are not going to get any more information from an expensive tool than you are getting from a cheap code reader. The possible causes for random missfire are many. Very often worn out plugs will fix it, but it could be low fuel pressure, could be flow sensor or O2 sensors or many other things. My long experience with those years of Ford pickups is it has to be running pretty bad before it will set a useful code and give you a cylinder number and even then it doesn't tell you why, just missfire. Then the next step ( if the spark plugs are good) is to switch coil packs to see if the problem moves or not.

 

[Haykid]

I have a innova 5310 I believe and I also have a f350 with a v10. I occasionally have a misfire and I can’t remember the code number now but if I remember right it would say something along the lines of “misfire coil A” for cylinder one and so on all the way through 10 but I don’t know if that was because of a specific code it threw or the scanner. Hope this helps
Haykid

 

[wore out]

If you are getting the random misfire code,, 300? I think? then you are not going to get any more information from an expensive tool than you are getting from a cheap code reader. The possible causes for random missfire are many. Very often worn out plugs will fix it, but it could be low fuel pressure, could be flow sensor or O2 sensors or many other things. My long experience with those years of Ford pickups is it has to be running pretty bad before it will set a useful code and give you a cylinder number and even then it doesn't tell you why, just missfire. Then the next step ( if the spark plugs are good) is to switch coil packs to see if the problem moves or not.

EXACTLY! PO300 is random misfire. P0301 is misfire on #1, P0302 is misfire on #2, etc..

I don't think if a specific cylinder misfire code has not been set throwing big bucks at a scan tool will get you any more specific info., more related to the age of the vehicle than the price of the scan tool.

 

[Butch(OH)]

I have a innova 5310 I believe and I also have a f350 with a v10. I occasionally have a misfire and I can’t remember the code number now but if I remember right it would say something along the lines of “misfire coil A” for cylinder one and so on all the way through 10 but I don’t know if that was because of a specific code it threw or the scanner. Hope this helps
Haykid

Yes, I forgot that on the older trucks Ford listed the cylinders by letter, not number. I think to confuse us driveway mechanics? it's easy to figure out. A is #1 B is #2 etc.

 

[johnnmr]

It's more than just codes guys, data stream information, bi directional controls etc are available with a more pro level obd2 scan tool.

Fords in particular have a cylinder contribution test when it shows which cylinder(s) are weaker, even if it's not enough to trip a misfire code.

 

[Butch(OH)]

It's more than just codes guys, data stream information, bi directional controls etc are available with a more pro level obd2 scan tool.

Fords in particular have a cylinder contribution test when it shows which cylinder(s) are weaker, even if it's not enough to trip a misfire code.

A cylinder weak enough to cause a miss will set a specific cylinder miss code, not the random 300 random code which signifies exactly what it says, a miss that is present in more than one cylinder in random, but consistent in no cylinders. We had the best testing equipment available when I managed the fleet. I've not seen a contribution test for a gasone engine of that era, maybe we missed something?? however the contribution vtest was an extremely useful tool from the beginning of the 7.3 DIT which was not OBTD2 until the Super Duties came out in 99 model year. I still have the special cables and OTC scan tool to check a Non OBTD2 7.3

 

[johnnmr]

A cylinder weak enough to cause a miss will set a specific cylinder miss code, not the random 300 random code which signifies exactly what it says, a miss that is present in more than one cylinder in random, but consistent in no cylinders. We had the best testing equipment available when I managed the fleet. I've not seen a contribution test for a gasone engine of that era, maybe we missed something?? however the contribution vtest was an extremely useful tool from the beginning of the 7.3 DIT which was not OBTD2 until the Super Duties came out in 99 model year. I still have the special cables and OTC scan tool to check a Non OBTD2 7.3

Your information is obsolete.

 

[joeysmith]

I have a cheap $25 scanner that gives codes when the CEL is on. Looking to step up a bit for one that will go a little deeper - like the issue I have right now. I have a 1999 Ford F250 with the V10 and I am getting a generic random misfire code. I know one (or two) of the COP have gone bad - what scanner would go deep enough to tell which cylinder(s) have the miss fire?

I dont know what cheap scanner you have but the app you use for it makes a lot of difference as well
Forscan goes pretty in depth if you have the right little module to plug in

 

[JDIH]

Autel makes some very good professional grade scanners that are reasonably priced. I have an MP808 that was about $800. Bidirectional controls, multiple PID graphing, access to all modules, touch screen, reasonably priced updates, internet access. Any scanner capable of mode 6 will work for finding your misfire. A cylinder contribution test was also available for fords of that era which is handy. Otherwise ford's misfire monitor sucks compared to GM's. Launch is another reasonable scanner. Reading codes is just the initial step in diagnosing, from there a comprehensive scanner is a must

 

[moresmoke]

For Fords, Forscan is hard to beat. I have 5 Fords in the yard. ForScan lite app on my phone and a $30 OBDII bluetooth dongle will do most of what I need. Once in a while I have to drag out a PC and data link to use the full version of ForScan. PC program is free, but needs to be registered for all features to work. Registration used to have a nominal fee, but that has been suspended for a while.

This program will read all the information and perform many service features, but does not have guided diagnostics that some of the $$$ scan tools provide.

 

[Stan Coryell]

I have a cheap $25 scanner that gives codes when the CEL is on. Looking to step up a bit for one that will go a little deeper - like the issue I have right now. I have a 1999 Ford F250 with the V10 and I am getting a generic random misfire code. I know one (or two) of the COP have gone bad - what scanner would go deep enough to tell which cylinder(s) have the miss fire?

If the ECM doesn't know which cylinder misfiring, a better scan tool probably won't help either. I use Forscan for my 1999 GT (4.6l), the ECM is somewhat limited compared to today's software.

https://forscan.org/home.html

Are they Motorcraft COPs? If so, I would let the dealer test them. The seldom "go bad"

I would start with checking the plugs, boots, springs, connections, coolant leaking into the plug well. None of the holes have the Dorman repair do they? See below.

I would also check the fuel trims, there's a good chance there are some vacuum leaks.

Hows the fuel pressure? Does it have a return, or is the pump variable volume?

 

[johnnmr]

If the ECM doesn't know which cylinder misfiring, a better scan tool probably won't help either. I use Forscan for my 1999 GT (4.6l), the ECM is somewhat limited compared to today's software.

https://forscan.org/home.html

Are they Motorcraft COPs? If so, I would let the dealer test them. The seldom "go bad"

I would start with checking the plugs, boots, springs, connections, coolant leaking into the plug well. None of the holes have the Dorman repair do they? See below.

I would also check the fuel trims, there's a good chance there are some vacuum leaks.

Hows the fuel pressure? Does it have a return, or is the pump variable volume?

View attachment 115821

That's partially true, a misfire has to occur X times before setting a misfire code, anomalies happen and are usually ignored. You'll have to get into the coding to know for sure why a p0300 random cylinder misfire is set VS p0301 thru p0310 for a specific cylinder.

Again, pro grade obd2 scan tools will show you TONS of data including misfires, both current and those stored in history. Even if there's no misfire code stored. Every vehicle manufacturer still does their own thing but the ability will be there in some form.

 

[johnnmr]

That's partially true, a misfire has to occur X times before setting a misfire code, anomalies happen and are usually ignored. You'll have to get into the coding to know for sure why a p0300 random cylinder misfire is set VS p0301 thru p0310 for a specific cylinder.

Again, pro grade obd2 scan tools will show you TONS of data including misfires, both current and those stored in history. Even if there's no misfire code stored. Every vehicle manufacturer still does their own thing but the ability will be there in some form.

For instance misfires aren't tracked when the computer thinks the gas tank is almost empty, it assumes any misfires are due to running out of gas. The misfires are clearly occurring but will not set a code.

 

[Barts Dad]

I had a similar problem on a 2001 Escape with 85000 miles. Friend suggested taking it to the parts store to have them check it. Went to the local Auto Zone they hooked it up and showed which one it was. Bought the new COP and about ten minutes in the garage at home and it was fixed.

 

[Mike(NEOhio)]

I had a '99 with the 5.4 and got severe misfiring. Took it to a local guy who had a probe he held on each coil. Red and green indicators on it sensed if the plug misfired or the coil didn't get the signal. Found a couple of bad coils but the real problem was the manifold leaking coolant into the plug wells.

 

[dhermesc]

It's more than just codes guys, data stream information, bi directional controls etc are available with a more pro level obd2 scan tool.

Fords in particular have a cylinder contribution test when it shows which cylinder(s) are weaker, even if it's not enough to trip a misfire code.

My truck has the missfire - but it hasn't been bad enough to trip the CEL. Although as noticeable as it is I have to wonder how bad it has to be to set off the CEL - complete nonfiring of the cylinder? I've seen the scan units that give the number of misfires per cylinder over a given period of time.

 

[dhermesc]

I had a '99 with the 5.4 and got severe misfiring. Took it to a local guy who had a probe he held on each coil. Red and green indicators on it sensed if the plug misfired or the coil didn't get the signal. Found a couple of bad coils but the real problem was the manifold leaking coolant into the plug wells.

I believe my truck still has about half the original COPs. When I bought it there was a bill for replacing the engine in the glovebox at 133K miles. It appeared they bought a short block from one supplier then bought heads from another. The bill was quite detailed and included new spark plugs installed - but no COPs. Whenever this engine gets wet it has another COP fail. I had rinsed it a couple times in the past and even just rinsing the road dust off the engine would be enough to start a COP to fail - but only one at a time. This week we had a lot of rain and driving it caused another to fail.

 

[NDIHC]

For instance misfires aren't tracked when the computer thinks the gas tank is almost empty, it assumes any misfires are due to running out of gas. The misfires are clearly occurring but will not set a code.

???? In all my years as a tech I have never seen that. What brand has this as an algorithm? I'd like to see the diag protocol that states that if you have a rough running engine that isn't setting misfire codes but has low fuel level, it is normal because the ecm ignores misfires at low fuel levels. If this exists it is a new one on me. Our manufacturer or any other training never mentioned this in any of my hundreds of classes over the past 37 years. Most cars I've had in that ran out of gas set misfire codes or lean mixture codes or both.