Long time reader first time poster, I have to say I've absorbed lots of info from this forum and has helped me on numerous occasions. I've done quite extensive searching on my problem before even contemplating starting a new thread but there were so many different variables from mine and the threads tended to end without a resolution being posted by the OP. That being said here's my problem:

Car specs: 2001 Dakota 2.5l 4cyl. 5 speed

I threw a code of p0505 about 2 months ago so needless to say my idle had sucked (would idle 700rpm above normal) I know that's my IAC so maybe after my post it could help with some answers regarding to the problem I've been having (I haven't replaced the IAC valve yet). A month or so after that code showing up while I was driving (car warmed up and had been driving for about 30 mins on the freeway) and when I came off a freeway interchange and started to speed up it started bucking at around 50-60mph I pulled to the side and it stalled. I restarted and limped to the gas station cause the gauge was close to E. But when I started it up and started driving through the parking lot it was bucking at low speeds as well, I pulled out and gunned it (I normally wouldnt be so rough with my car but it was a crap day) and it was bucking till I got to a little higher of a speed like 30mph. All this bucking happens when Im physically pressing the accelerator. I drove for a few weeks like that and it wouldnt happen very often for how much I was driving.

I took time off work to look after my sister who is having health issues so it became a low priority and I also have another truck so I eventually garaged the dakota. A week after garaging I went down to start up the truck and while in neutral I tried giving it gas and around 3k rpm it wanted to stall and did after taking my foot off the pedal. I tried restarting and it wouldn't turn over. I tried quite a few times till my dash lit up like a xmas tree and where the digital odometer is (where you can display trouble codes) it displayed a few letters but forgot to write it down and it was over a month ago and figured it was just a glitch from trying to restart/turning the key on/off rapidly. Plus every week after that I was able to restart while parked, but it would stall again.

I need to get my truck back on the road for multiple reasons but one being I really don't like driving my Ford Ranger cause..well its a Ford. So today I went down into the garage it started up right away like usual but this time I was able to rev it up quite a bit and it didn't hesitate like before (last time I started it was 3 weeks ago, so that was the longest period of time between starting up my truck) but when I let off the gas the last time it stalled and wouldn't start again like prior attempts.

 

So out of the blue when I woke up this morning it hit me what display I got in the digital odometer/trouble code display. It was "nobus". I was only able to duplicate it twice that same morning I mentioned before when I continually attempted to restart my Dak. I'm really gonna feel like an idiot if it's just the IAC p0505 code but I don't see how a bad IAC valve would cause the bucking. I feel like it's a fuel issue like the pump not having enough pressure and I'm only able to start it momentarily because of it priming/building up while waiting between days/weeks of starting.

 

Too me it sounds like your PCM/computer crapped out as my 2.5 did just that before it died on me.

 

Thanks for the input. Yeah I'm getting the "nobus" signal thrown at me again. I'd like to do some more testing to make sure it isn't like the signal from the cps or something minute. We're you getting a bucking while accelerating

 

Very bad bucking very violent it was scary the weird thing was it wasn't constant it was on then off good days then bad days. It also would just cut out at times and be hard to start.

How to test I cant say I had a shop do that for me at that time in my life.

 

Yeah you described it better in one paragraph then I did in 5 haha. I'm gonna go grab a new volt meter cause mine is a piece and then then start measuring voltage coming from the pcm before and after attempting to turn over. Just waiting on someone to email the right diagram now. Thanks for chiming in with your experience I really appreciate it. I didn't really think it was the fuel pump because I can hear it priming just sitting in the cab and a pcm will only set me back a couple hundred.

 

You can download a full copy of the 2001 service manual from this thread:

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

Check the cam and crank position sensors. They can short out the bus.

 

Yeah you described it perfectly. I actually found the culprit while I was unraveling the electrical tape and wiring loom on the harnesses to the pcm to start running the volt meter. 5 wires were dry rotted and one was completely severed which was the reason it was mimicking a bad pcm. So I busted out the soldering iron to lengthen and replace (to run the harness out of the heat from the exhaust manifold) the wires and boom started right up. What would have cost me a couple stacks cost me a couple bucks.

I know most people solve their problem and then never post what the solution was, which gets frustrating, so hopefully this will help someone in the future. Thanks 98DAKAZ for chiming in with your input too.