2.9 misfiring and loosing spark randomly when warmed up

[Zapper]

So when i go for a drive and cruise around 2500rpm at 55-65 mph it bucks as if it is misfiring and loosing all spark for a second or two then spark comes back, and im wondering if anyone else has had this problem and what the problem was, im guessing the tfi module because i know those things hate heat and it only does it after like 30 mins - an hour so if anyone has any ideas as to what it is it would be great if you could help.

 

[franklin2]

Try the TFI module first. If that doesn't fix it, then it can be the pickup coil inside the distributor that sends the signals to the TFI module. That's what it ended up being on my 86 ranger with the bucking.

I got a new pickup coil, and when I went to install it I was careless and broke some teeth on the distributor drive gear, it must be removed. I looked all over the whole country for a new gear, people said they had one but they really didn't. So I finally got a rebuilt cardone distributor from the parts store. Installed it, it was worse than the original one. So I took the cardone apart, (more carefully this time) cardone had not even taken it apart to clean it, it was full of old carboned up grease and oil. I cleaned it up, put the new module I had already bought in the "rebuilt" distributor (for $80 they had not even changed the module with a new one) and greased it up and put it back together and it ran like a champ.

 

[RonD]

TFI is most likely to cause what you describe

But overheated Coil can as well, you can't really test an ignition coil

 

[Zapper]

Try the TFI module first. If that doesn't fix it, then it can be the pickup coil inside the distributor that sends the signals to the TFI module. That's what it ended up being on my 86 ranger with the bucking.

I got a new pickup coil, and when I went to install it I was careless and broke some teeth on the distributor drive gear, it must be removed. I looked all over the whole country for a new gear, people said they had one but they really didn't. So I finally got a rebuilt cardone distributor from the parts store. Installed it, it was worse than the original one. So I took the cardone apart, (more carefully this time) cardone had not even taken it apart to clean it, it was full of old carboned up grease and oil. I cleaned it up, put the new module I had already bought in the "rebuilt" distributor (for $80 they had not even changed the module with a new one) and greased it up and put it back together and it ran like a champ.

So i replaced the tfi module and the problem still occurs but not as often, so how hard is it to replace the pickup coil? Because im not having much luck with finding videos or information on how to do it.

 

[franklin2]

Here's a video.

Don't do what I did and use a jawed puller on just a couple of teeth if the gear is stuck.

 

[franklin2]

I bought one of these at harbor freight and used it instead on the 2nd one. They are abut $30.

 

[Paulos]

The hardest part of changing pickup coil is driving the roll/spring pin out of the distibutor gear, and then back in again. It's best to use a vise and a 1/8" roll pin punch, along with some kind of solvent to dissolve the baked on oil/varnish that builds up on the shaft just above the gear. If you gently twist and pull the shaft up and out of the distributor body while soaking it in the solvent it will come out without too much work. So if you've got the vise and roll pin punch it's not that bad.

Oh, and the hole through the shaft that the roll pin goes through is not centered in the shaft. So if the gear is put back on 180° out, the pin will not go back in.

 

[Zapper]

I bought one of these at harbor freight and used it instead on the 2nd one. They are abut $30.

Well i replaced the pickup coil and my problem still persists im beginning to think it may be injector related since i have 30+ psi of fuel pressure and i have cleaned out the IAC

 

[franklin2]

You have the standard unknown problem some of these older trucks have, mine had it several times. One other time it was not driving correctly, and I kept checking the codes now and then. Finally I got a TPS error code. I bought one and changed it and those problems when away. I find the old EECIV system difficult to troubleshoot. They are not very friendly when it comes to data streaming and logging.\ But if you pull the codes, sometimes they will give you a clue.

 

[Paulos]

I had an issue a couple years ago with the "bucking", but it started within 5-10 minutes on my way to work in the morning. Once it warmed up, the bucking started. I had already gone through the rest of the fuel system, and read online that bucking was typical of injector problems. I bought some "remanufactured" injectors, but they didn't work very well. New injectors solved the problem.
I didn't mention the injectors in my first post because you said it did this 30 minutes to an hour later. I once had an ignition module that 3 days in a row would quit at the same exit, about 30-40 minutes after leaving work for home. I would pull over, check to see what the problem was, and find nothing. About 10 minutes later I would try starting the engine and it would run okay until I got home (about 10 minutes away). I figure that 10 minutes was time enough for the ignition module to cool down and start working again.
The bucking sounds like it could be injectors, but the time frame sounds like the ignition module or pickup coil. When the engine is cold, the engine runs in open loop mode. When it warms up, it runs in closed loop mode, which is when the bucking should start. It only took about 5-10 minutes for the engine to warm up.

 

[89Twincharge]

I work at a shop and we had a ranger come in like this... the shielding for the ignition wires had actually rubbed through the wire insulation and was causing it to ground out ignition when driving.. with your truck running follow the plug from your TFI plug and jiggle it all the way to fire wall... if it misses while your doing this it's the problem.

 

[Zapper]

You have the standard unknown problem some of these older trucks have, mine had it several times. One other time it was not driving correctly, and I kept checking the codes now and then. Finally I got a TPS error code. I bought one and changed it and those problems when away. I find the old EECIV system difficult to troubleshoot. They are not very friendly when it comes to data streaming and logging.\ But if you pull the codes, sometimes they will give you a clue.

I would check codes if i had a check engine light, my gauge cluster never had it to begin with, my tps is fairly new since i had to replace it since it actually failed on me while driving but ill keep troubleshooting

 

[Zapper]

I had an issue a couple years ago with the "bucking", but it started within 5-10 minutes on my way to work in the morning. Once it warmed up, the bucking started. I had already gone through the rest of the fuel system, and read online that bucking was typical of injector problems. I bought some "remanufactured" injectors, but they didn't work very well. New injectors solved the problem.
I didn't mention the injectors in my first post because you said it did this 30 minutes to an hour later. I once had an ignition module that 3 days in a row would quit at the same exit, about 30-40 minutes after leaving work for home. I would pull over, check to see what the problem was, and find nothing. About 10 minutes later I would try starting the engine and it would run okay until I got home (about 10 minutes away). I figure that 10 minutes was time enough for the ignition module to cool down and start working again.
The bucking sounds like it could be injectors, but the time frame sounds like the ignition module or pickup coil. When the engine is cold, the engine runs in open loop mode. When it warms up, it runs in closed loop mode, which is when the bucking should start. It only took about 5-10 minutes for the engine to warm up.

My injectors are probably needing to be replaced... knowing my luck they are probably the factory ones, plus i sometimes try that fuel system cleaner stuff and it seems to work for about a week, so im guessing the previous owners let it sit for awhile and the ethanol in the fuel may have gummed up the injectors..

 

[Zapper]

I work at a shop and we had a ranger come in like this... the shielding for the ignition wires had actually rubbed through the wire insulation and was causing it to ground out ignition when driving.. with your truck running follow the plug from your TFI plug and jiggle it all the way to fire wall... if it misses while your doing this it's the problem.

Ill try this when i get a chance, having to find a coolant leak on a kia first though because thermostat failed and caused it to overpressure and push through a gasket

 

[Bird76Mojo]

Is it using any coolant?