Nickel and diming

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... me to death...
It's been one issue after another with this damn dodge ram.
Now I have a mystery misfire under load at around 1750 to 2250 RPMS. I can't get it to misfire just sitting in the driveway. It's random and sporadic. Usually in 3rd gear sometimes in second. Manual trans, 95 ram 1500 , 5.2 Magnum. New plugs , wires , cap , rotor , TB has been cleaned , new 02 sensor, TPS, IACV , maf sensor , brand new battery, alternator , 180* thermostat and water pump. New breather, grommets and PCV . It has been gradually getting worse. The plugs look brand new. Any one have the same issue with a cure ? Lol thanks
 
If it makes you feel any better my engine has maybe 500 miles on it since the rebuild and it's been nothing but problems. I was fighting a random missfire for 2 months, turned out to be the either the PCV valve or fuel filter. Both were new but I replaced them on a whim since I had 2 new ones on the shelf. Replaced them both at the same time and problem disappeared after.

Car was running great for less than 2 weeks and now an exhaust leak on the passenger side manifold at the head. I don't have room to work on it right now so back to the mechanic on Monday...
 
do you have the plug wire arcing issue? my old ram had a arcing plug wire issue before i owned it. there was the coil mounted with a special plug wire that ran up to the front of the engine? i dont remember exactly what was different than stock but i do remember the p.o. telling me about the issue when i bought the truck
 
Only thing I can think of with being under load maybe the coil is breaking down. Course that's just a guess.Had an accel coil on mine that would mis fire when I romped on it. Threw the stock coil on and it cleared right up.
 
Just gonna mention "Intake manifold valley pan gasket" because it's not on your list of fixes and those are kind of a "when, not if" problem...

I know when the coil went out in my Jeep it started cutting out around that speed usually during a steady cruise (light load), however that's a 1993 with the OBD1 system, I don't have experience with the later OBD2 JTEC system like in your Ram.
 
Look at your idling engine in the dark. That's how I found my coil randomly arcing on the terminals. It would start to misfire at higher rims. I replaced the coil and the problem was solved. I also managed to detect an arcing spark plug leaking from under the boot.
 
Just today I rerouted the plug wires so they aren't crossing , they are Taylor 8.5 mm, not cheap. I also moved the coil wire around to. None of it made difference. There was a tad bit of oil down in the intake so there is some kind of leak . I just don't think that would cause this kind of misfire, it's like one cylinder completely stops firing for a few minutes and then back to normal. I'm thinking maybe an injector or crank sensor, but I really don't know. I may try a new coil just for *****. No check engine light what so ever. Thanks for all your replies
 
Did all the plugs look exactly the same like the miss was jumping around to different cylinders?
Or did one plug look a little darker like it was randomly missing on the same cylinder?

That might be a clue.

I know, Greg's questions are a pain in the a**. :D

Also make sure your coil wire isn't burning the core out of it.
You should see the center core crimped under the metal ends around the wire and continue down the center of the wire.
If either end has black residue on the metal the core is burning out of the center of the wire.
This causes a miss that gets worse as more of the core burns and causes the gap in the core to get bigger and bigger till eventually the spark won't jump the gap any more as cylinder pressure climbs from more throttle.
 
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The #1 has a light discoloration compared to the others, they are only about 6 months old. I will check out the coil wire tomorrow , that could be a good lead.
 
Sorry long winded.
How heavy of a mis fire are you seeing? Also there are some issues with the interface of some after market O2 sensors as far as their operating parameters. I can't recall who makes them for Mopar (NGK maybe) but everything I found on line when I dealt with my Durango said use the OEM or the company that made them for Mopar. Also don't loosen and rotate the distributor, If you turn the distributor there is like a "phasing" that has to be reset thru the obd with an oem style scanner such as snap on. I lent out my 99 factory manual but there also several sensors that share a power source and I believe they were iac, crank and tps and passes thru the heat circuit for the forward 02. So any one of these being out of range can cause an issue that won't necessarily throw an obd code. There were also issues with control modules failing and doing wacky stuff. Don't own it anymore. Not trying to muddy the waters, but just putting out some info I recall that I went thru. And as mentioned here and another thread the plenum gasket, high oil usage, pinging, low power and crappy mileage.
 
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I haven't touched the distributor, and the O2 sensor is an aftermarket universal type, which I'm also wondering about. I've heard some bad things about the computer as well.
 
73AbodEE said:
I haven't touched the distributor, and the O2 sensor is an aftermarket universal type, which I'm also wondering about. I've heard some bad things about the computer as well.
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Just throwing this out there. My 3.9 Dakota had symptoms like your 5.2 and after going thru everything I could think of I took to a garage and they said it was the bushing for the oil pump intermediate drive. I replaced the bushing and drive and that fixed it.
Don't know how many miles you have but it might be something to look at.
If you take the intake off to replace the gasket then do the bushing at that time.
 
bobscuda67 said:
Just throwing this out there. My 3.9 Dakota had symptoms like your 5.2 and after going thru everything I could think of I took to a garage and they said it was the bushing for the oil pump intermediate drive. I replaced the bushing and drive and that fixed it.
Don't know how many miles you have but it might be something to look at.
If you take the intake off to replace the gasket then do the bushing at that time.
Click to expand...
That's crazy a bushing would have that kind of effect. When I do the intake I will check it out.
 
Those intake plenums are junk and it's probably leaking. So much they make a heavy duty aluminum piece that bolts on instead of the oem tin. Could this be the misfire? It's hard to say.

But I have the Hughes plenum kit bolted on a clean, naked intake, never been ran on an engine that I went with a 4bbl FI intake instead. I'll sell it cheap. Pm me if you're interested.
 
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Don't mind the tape residue, I covered all the ports for paint but never painted it. It'll all be cleaned off before shipment.

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