As my name suggests, this truck is a 1997 demon child. It is a 1997 Dodge Ram 1500, 5.9L v8 auto trans 46re, 4x4.

Ive been dealing with a mysterious misfire issue for the past 3 months. Ive put about $1000 worth of new parts into this damn truck and im at my wits ends.

New parts list:
fuel pump
Fuel filter
Fuel lines (all of them)
spark plugs
plug wires
Coil pack
Distributor cap
Distibutor rotor
Ignition pick up coil (inside the distributor)
Purge valve
IAC Valve (idle air control valve)

Ive done a compression test and all 8 cylinders are at 150psi. Recently found a massive vacuum leak at the MAP sensor, fixed that today. Fuel injectors have been moved around and even swapped out with a few junkyard pieces.. The misfire has not moved.

Now, heres whats happening. At start up, it runs beautifully, and i can rev all the way through the rpm range. While driving though, i cant rev past 3000rpm, the truck will loose power and speed going up hill. The codes that it is throwing are, P0300 (random misfire) P0301 (misfire cylinder 1) and P0302 (misfire cylinder 2). Every now and then it will thow in another random cylinder too. (Today for example, it was #7.

I have been on the phone with 8 different dodge dealerships fron around the country and they all have no idea what is going on...

HELP!!

 

The dealership won't troubleshoot over the phone. They want you to bring it in, so they can charge you 100 bucks (or more) per hour, for diagnosis. (even if they knew EXACTLY what was wrong, they wouldn't tell you...... )

The sensor under the distributor cap doesn't do anything with ignition. (even though its commonly called a "pick-up coil") In reality, it's the cam position sensor. It affects injector timing, and that's it.

Does the truck run ok for the first couple minutes after startup (when stone cold), and then start screwing up after about two to three minutes of running?

Quick test 1: Unplug the front O2 sensor. Go for a drive. Any better?

If not:

Quick test 2: Remove the O2 sensor from the exhaust. (front sensor again.) Go for a drive. Any better?

Take a look down the throttle body, at the bottom of the intake plenum, see any oil pooling in there?

What spark plugs did you install? Did you route the wires per the TSB? (that's available in the faq/diy section here.)

Welcome to DF!

 

Nothing was mentioned about the plenum gasket. I would look there first! The fix.

 

Issue has been resolved. Turned out to be my front crankshaft seal. Would also explain the massive losses of oil that i have.

 

Crank seal shouldn't give you a miss......

 

Could it be "ye old TSB 18-48-98":Date: December 30, 1998
1994-1999 BR/BE Ram
Note: applies to vehicles with 3.9L, 5.2L and 5.9L engines (gas)1994 - 1999 (AN) Dakota
1994 - 1999 (BR/BE) Ram Truck
1998 - 1999 (DN) Durango
1995 - 1999 (XJ) Cherokee
1994 - 1999 (ZJ) Grand CherokeeSymptoms: some vehicles may exhibit one or more of these symptoms:

• spark knock complaints with vehicle under load
• various single cylinder misfire (1, 3, 7,) ad especially 5 and/or 8
• surge in 4th gear with the Electronically Modulated Converter Clutch (EMCC) engaged (around 45MPH).
• Perceived torque converter EMCC engagement/ disengagement around 45 MPH.

TSB Link

 

Issue has been figured out... Turned out to be the intakd plenum gasket. So after replacing every gasket on the top end and dealing with a broken manifold bolt, i finally got it all back together and torqued to spec, it ran far worse than before. Wouldnt rev past 2100 rpm, and when driving wouldnt drive past 25mph. Catalytic converter was plugged (but not quite) took out the front o2 sensor and she ran fine, took out the exhaust and decided to just hollow out the cat, and when i cut it open, i found that the honeycomb on the inside had broken into 4 pieces and turned sideways. Got it all buttoned back up and now i cant get the transmission crossmember back in place. I read another thread here on the forums, and i have a few ideas.... Any of you guys/gals have any tanerite?? Lol

 

Explosives are not the answer. (though, I will grant, it can be rather soul satisfying....)

Need to spread the frame a bit, and drop the crossmember in from ABOVE it's mounts. They are tapered.

 

Ok so this truck really is a demon child. Got everything taken care of listed above and truck runs beautifully... But. When cold the truck runs fine, as soon as the temp starts to go up, the truck wont hold oil pressure. At first i thought it was a head gasket and i checked for that. It IS NOT THE HEADGASKET. I seem to have oil that is leaking into my cylinders from the top end. Its not the plenum gasket again (as there is no pooling in the intake) please help.

 

Did you retorque the manifold bolts?