My plugs all identical and I can feel the misfire now but the CEL is off.
The RPM was a little low sometimes 600 one time and 750 next time so I changed the IAC and it's constant at 750 but still misfires after it sits and idles for more than a min. CEL comes on after I pull out to pass on highway and take it from 60mph to 75mph and let off to pull back in. If I drive at a fast highway speed for a while and slow to exit the light will sometimes come on. always P301 P303 and P305. It's an automatic so I don't take my foot off gas to shift only to stop, I thought that the IAC was slow to react so I changed it. but still does the same.
I want to upgrade to the 5.2l throttle body , parts. are waiting until I fix misfire.

 

Mine does almost exactly the same thing, Idles @ 750 and suddenly drops to almost a stall. At 55mph the truck feels like I'm hitting patches of water. And I have no power, but sometimes it will feel like a turbo is on the truck. It will just scream for a day or so, no misfires, then I stop at a light and it runs like trash again. At 65 and up I don't feel the miss in the engine. When I replaced the +4 Bosch that I was running I had no carbon on them, just a light cream color from the heat. Other than that they looked to be in good shape.

 

When it runs good it's great, when it acts up I fell like parking it and driving the wife's mini van.
I've replaced everything:
PCM, fuel pump, switched injectors from one side to other. IAC, MAP, TPS, plugs twice, wires twice, cap twice, cam position sensor. Next to be changed is the coil and I might change distributor I'm thinking that the bushing might be warn out, limited budget now so parts will have to be used or borrowed.

 

Save your money on the coil and distributor, neither one has changed mine at all. I have a new coil and pulled the distributor to get that broken screw out. Of course I looked at it really good and let the Mopar mech. look at it too. Said it was fine. I'm checking the compression this Saturday. Don't know what I'm looking for exactly, other than no more than 15% difference in compression over all 6 cylinders. I'll post the #s I get and call my mechanic up at the Dodge dealership also. I think he may end up tearing down my motor just to see what has him so stumped.If he does, I won't be unhappy about it at all!!!

 

I'll save my money.
My buddy just got a '99 Durango in to his shop to replace the transmission its got a 5.2 in it so I'm thinking I will burrow motor for a couple of days and see if it helps my truck.

 

Wow, that seems like a lot of work to swap a motor for a few days. But if it works let me know. Because I have a bad feeling that a rebuild might be coming my way, and I'd rather have an 8 cylinder anyway. Won't hurt the gas mileage I have now

 

OK, just finished putting the Dakota back together and I'm not happy with what I found...
Cylinder #1:140psi
Cylinder #2:155psi
Cylinder #3 120psi
Cylinder #4 100psi
Cylinder #5 130psi
Cylinder #6 130psi
So I do have a compression problem in the engine, I think #4 is probably the rings. However I can't say for sure. Let me know what you guys think. Thanks, Chris J.

 

are the banks 135 and 246?
I thought they varried about #20 from one side to the other. #4 looks to be causing a problem.

You can also check to make sure that the spark plugs wires are routed away from one another, they arn't touching or could be getting any interferience from anything else electrical. Also. Take the plugs off, and use a volt meter and probe one end, and test the other end, these should all be very close to one another.

 

"are the banks 135 and 246?"

I don't know what that is...

The dodge mechanic told me that there should be no more than 15% difference in compression between any two cylinders. I don't even know what the compression should be. And I replaced the fuel injectors less than 6 months ago (Bosch). I don't want to rebuild this engine, I just spent $2600 on a new tranny that I shredded a few weeks ago. Any ideas...

 

If you just bought a new tranny for that price, you should have a warranty. Your compression is off and that is going to cause problems. Given one cylinder isn't functioning correctly, it could cause that whole bank to go into a frenzy.

Do you have a warranty on your trans so you don't have to spend anything? If not, it's time to start looking for a junk yard motor.

If you have a daily driver, figure out the trans, and let the truck sit, You can do a 5.2/5.9 swap for 2k or less with a used higher milage motor.

What do you want to do with the truck?