So, I have searched on here for two days looking for the cause of a misfire that I have. I have not found a thread that has the same issues that I am having.

On start-up, the engine idles great. During driving, it powers well. Once I get to whatever speed I am traveling at and let off of the throttle ever so slightly, the engine begins misfiring and causes the truck to sorta stumble like it is stuck in a high gear.

What has me stumped on this is, it did not start until I replaced all of the plugs, wires, cap, and rotor. Now I have went through every plug individually, gapped them and replaced them with no change. I pulled the cap off of the distributer and there is no play on the distributer. I plan on pulling every wire and testing each one individually tomorrow. Hopefully it is just a bad wire.

I have Sea Foamed the gasoline, thinking I had a dirty injector, and there has been no change with that either.

If my truck is in park, and I rev the engine to about 1500 rpm's, I will feel and hear the misfire. It will actually backfire.

Had the cat replaced and replaced both O2 sensors within the past year.

If anyone has any ideas what it may be, I would greatly appreciate it. I would much rather try and fix it myself than take it to the shop.

THanks,
Jason

99 dodge ram 1500
5.9 360

 

There could be a problem with the CKP (Camshaft Sensor). It could be dirty or even the pigtail could be dirty. That happened when I rebuilt my engine. Pull the distributor cap, remove the CKP, inspect it for cracks and dirt, clean, put dielectric grease on the connectors, and reinstall.

Also, there's a specific routing required for the 5.2L and 5.9L engines. If that is not followed, misfires can result.

Good luck.

 

The SAME thing has been going on with my truck forever. Mind you I bought it with a lot of problems and fixed them all, but this is the one thing I can't get rid of! I've never tried to see if it backfires at 1500rpm, but it sputters once you let off at whatever speed... its usually between 18-2500rpm though.

One thing I haven't tried was the wire rerouting tsb or whatever. I'm not sure where it is on this site.

 

you could have the wires routed incorrectly from to each plug to the cap, ie: plug #1 is connected to #3 on the cap.
the last time i changed my wires i wrote the wire diagram on the back of my hand and when i did the drivers side i read the diagram upside down. so that whole side was backwards. it idled great, but when i revved it just a little bit (about 1500 rpm) it would back fire because each cylinder was firing at the wrong time.

 

I will look at the Camshaft sensor tomorrow. I would like to know what this (TSB) that I have seen is. Also, when re-applying the plug wires onto the distributor cap, starting at the number 1, should all of the wires go on in a clockwise rotation? The firing order is on the top of the engine, but I need to know if the plug wires go on in a clockwise rotation or counter clockwise.

 

i have read on this site if the #5 and #7 wires touch it could cause misfiring because they fire right after each other...

 

clockwise starting from the number 1 position on the cap.

the crossfire from not doing the wire re-route isn't that big of a deal when the wires are brand new.
http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8.htm

the drivers side of the motor from front to backs cylinder #s are 1,3,5,7
the passenger side is 2,4,6,8

the firing order is 18436572

can you see how i numbered the cap before i put it on? that helps in getting the correct order. i put the numbers on both sides and above and below each post so i would be guaranteed to see a number even with the wires plugged in.

 

http://dodgeram.info/tsb/1998/18-48-98/18-48-98-v8.htm

And all the TSBs you could ever need!
http://dodgeram.info/tsb/index.html

 

too slow purpl

 

Well the wires are mopar wires, not the discount store stuff. I tried to make sure they were not touching, but I am going to attempt to secure them as per the TSB thingy that was sent. The firing order as given above was what was followed aswell as the clockwise rotation. I am bout at my whits end here.