Okay guys please help me out here cause I am running out of options. I have 3 codes showing on my 97 1500 for cylinder 4 and 7 misfiring and then P0300 which is multiple random misfires.

Here is what I have already done: I changed sparkplugs and tested the spark. There is spark. I swapped out the fuel injector in the #4 cylinder and checked the ohms and its good. The distributor cap is relatively new so it should be fine, plus i check to see if the plugs are getting spark and they are. I changed the O2 sensor's. Please note that I have headers back to a cat with straight pipe off the cat.

The truck has about 240k on the eng but was running fine until the other day when i was leaving work to get on the freeway and a jumped on it and took it to about 4800RPMS. When i got off the freeway the whole truck was shaking at idle with it about 200/300 rpms low. When i am going about 40-50 MPH with overdrive on the RPMS will be around 1400, if i gas it just a little to speed up they jump to 1500+/- 100rpms and then drap to 1300ish and the whole truck shakes. I figure this has to do with all the misfires. Please I am running out of options other then the timing chain jump a tooth or the PCM when out...someone HELP ME!!!

 

Shaking at 40-50 MPH is the misfire.


There is a TSB for the sparkplug wire routing technique. I think it might be in the 2nd gen faq section. It specifically dictates where to put the plug wires, mainly numbers 4,8, and 7. Go find it, re-route your wires and see what happens.

 

Thank you for the input. I have been searching and can't find that anywhere on the thread. WHich sucks Because I would really like to try it. If you have any idea of a more specific spot could you let me know. That would be awesome

 

If you'd post in the correct section, you'd be able to find it quite easily. :-)

https://dodgeforum.com/forum/dodge-r...s-section.html

I'll give you one hint for the TSB regarding the spark plug wires' routing: its in the 2nd Gen Ram DIY section, and you can find how to get to that by reading whats at the above link.

 

The post in the DIY section is a real good reference but the photo's don't work. I wound up using the link below along w/ the one in the DIY and all worked out well.

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

 

if the rerouting of the spark plug wires doesn't work do a cylinder compression test. with 240k + miles its possible you have low compression

 

I did a compression checkl they are all at like 60 lol so yes they are all low. I look at the sparkplug rerouting. I think its already been done. cause all of the wire holders and what nots are on the truck already.

 

With that low of numbers I would start looking for a new motor..

 

Seconded. OP is 40% below minimum spec. No wonder it doesn't wanna run right.

 

Suddenly I feel a whole lot better about my numbers. I wouldn't even think the engine would run with compression that low.