Hey y'all, I didn't see anything when I searched for this so my apologies if it's already been covered.

Working on truck in sig, up to about 240,000 miles. Just had ECM rebuilt, only throwing 1 CEL, P0455 (large evap leak) haven't been able to clear it (been that way for a couple years) chased down and replaced every hose I could get to including under the truck.

My problem now is the truck starts to almost violently jerk around 50 mph and above while accelerating, also noticed the last time I drove it that the CEL will flash while this is happening. I'm thinking the timing chain is due for replacement (hearing a noise from the motor that sounds like a possible chain, plus at this mileage it's probably due) so I've already got that planned, just wondering if that could be my problem or if I need to look elsewhere while I'm under the hood.

Thanks in advance for any help!

 

A CEL means something is wrong. A flashing CEL means something is really wrong. Check your codes again. you can check them with the key - on/off/on/off/on and the odometer will tell you what they are then end with PDONE.

If you slowly (like 4 seconds slow, not like a minute slow) run the tachometer up to about 3000 rpms will the needle do a smooth sweep or does it jump a little between 1500 and 2500 rpms?
Can you redline the tachometer with a quick hit of the gas pedal?

How old are your plugs, wires and the cap/rotor?

Check all of your vacuum lines for cracks/breaks.
Check the hoses and lines going to the charcoal canister under the truck like in this thread.

https://dodgeforum.com/forum/2nd-gen...-leak-fix.html

Quote:

Causes

A code p0455 most likely means one or more of the following has happened:

Found this in a different thread

 

At about 45 to 50 mph these trucks go into overdrive, which is where you'll start to really feel any misfires that are happening. A flashing CEL under acceleration usually means a misfire.
First thing would be to check codes to see if it tells you which cylinder is acting up. P0300= multiple misfire, P0301-308= which cylinder is missing... IIRC.
You should also do a general check of the ignition system. Look for burnt/ cracked wires, check the inside of the cap and the rotor for build up / burnt contacts, and check the plugs. You're looking for anything obviously wrong, and hopefully and easy fix. If everything checks out okay, then it's time to start doing more troubleshooting.

 

Thank you all for the responses, I apologize for not replying sooner, kinda had a little SNAFU here at home, and just now got internet back online and got everything settled. Problem turned out to be plugs/wires. Did plugs, wires, cap and rotor just to cover everything, but plugs in 5 out of the 8 cylinders were running hot and had that wonderful yellowish/tan glaze and the ECM eventually did throw a misfire code for cylinder 6 before I was able to replace everything. for what it's worth, I was running NGK/R plugs, guess the truck doesn't like them, so I went back to Champion coppers. also got rid of the expensive (overpriced) 8mm Taylor plug wires (half the boots tore off or left the metal clips attached to the plugs when I pulled them) went back to basic OEM plugs, wires, cap and rotor.

 

Glad you got it done and thanks for the update. We always want to know what the final fix was.

 

So I am having a similar problem as the original post. I know this has been awhile but I don't want to make the same post. My truck is giving no codes (2000 Ram1500 with 5.9L) but I jerk above 60mph. Tranny shops says there is a misfire but I have new plugs, wires, cap and rotor, and ignition coil all within the last year. My next guess is distributor or fuel injector? Any tips?

 

Which plugs did use? There is a TSB on proper spark plug wire routing.
A misfire "might" throw a code though.
What does the "jerk" sound and feel like?