Krlspokane12

I called ddp and they said there has to be a different issue with the smoke and rough idle. The truck idled about the same as it did with the 100hp dap injectors that were in it and they were matched. DDP said look at the vp or electrical problems. So I could just swap on some dap nozzles and rest pop pressure and be good?

Can I just swap the nozzles? Or set pop pressure higher? If so, any suggestions? These were expensive, don't really wanna ditch them completely.

So, I decided to start a new thread on this. My truck has been running like crap since I installed my 100hp ddp injectors. I know they set the pop pressure at 290, which is low. But when it's idling, or driving under light throttle it almost sounds Iike it has a fuel knock. Not sure what is going on, but is there any reason why I can't pull them and set pop pressure to 320? Not sure if this will help or not. They are really smoky, which is the nature of them I guess, but it leaves a slight clearly visible haze even driving under lite throttle, so not sure if there are other underlying issues. Truck does have a airdog 100 and a new vp.

Should I pull those ddp injectors and reset them? They are all (double checked) set at 290 bar, I know that's low but it what they called for them to be set at. It might help a little bit, but I had the prior dap injectors set at 315 and it still ran like s**t but not nearly as bad

So, im putting a breakout box on the truck Tuesday. So, if it runs perfectly with the break out box on, what should I look at next ECM? I don't know what else it could be at that point...?? Alternatively, if it runs like **** it has to be either the vp or injectors.....correct or could it be something else??

I will do a hot wire test this weekend. I did notice today that the idle was off slightly while sitting at a stop light.. its not as bad as when in park, but it is noticeable.

so if i hot wire the VP and it idles fine, then is it ECM or wiring or something else? Where would be the first place to start?

I have been wondering if doing the WT mod would solve my problems or just help prevent other issues. Either way its a good idea.

I checked the APPS a few weeks back and it was out of spec, so i reset to the specs listed on it. So, its funny that you mentioned temp sensor, my temp gauge is messed up, it reads 190 when cold and 220 when warm, but was 192 from OBD.. more mysteries. So here's a thought, could I hot wire the VP and see if that changes the idle? Wouldn't that eliminate the ECM from being the issue?

LOL, you have no idea man, i appreciate every ones input, but i cant for the life of me figure this out. Its getting old loading up the "parts cannon" and just throwing money at it. I dont know what else there is to replace.

So it might be the ECM or maybe a bad APPS? I spoke with a mechanic I know and he said it might just be a s**t reman VP or the wrong VP for the truck or the keyway was reversed.. i dont know enough about it. But he said that it might be why it smokes so much and the idle is all funky.

I was thinking ECM because a local company was in it a few months back. Something happened with the ECM when the VP failed. I'm not sure what they fixed. Also, it started running better after i had it re-flashed by dodge 2wks ago, then started running crappy again. So not sure if that is related, but ive heard stories about these ECM's doing weird stuff after some one has been in them...just more food for thought. Also today it started idling funky while i was sitting at a stop light, not as bad as when it is in park, but off enough to notice..

I noticed that when in gear the tach is dead steady at 800rpms, but in park or neutral it bounces between 800 and 900rmp,

yes, neutral is the same as park.

I wasn't thinking it could be injectors since it did the same thing before i put these in. In regards to the injectors, i had them all pop tested and flow checked prior to install. This is the procedure i followed when installing the injectors. Once the injector was in the hole, I tightened the hold down to 40in lbs to seat the injector and then backed off the bolt. Then i inserted the connector tube until i heard a "click", and then double checked the tube was seated all the way. Then the hold down was retorqued to 89 in lbs. So is it incorrect to seat the injector first and back off the retainer? I also used new Bosch connector tubes when i installed the injectors. Another thing, it only idles like crap when its in park. If there is any load on the engine, the idle smooths out.

I adjusted the valve lash when I installed the injectors and set to cummins specs. There is some slight idle haze when cols started, but that's normal. Truck runs great, plenty of power and go-go, just a crappy idle.

more brain storming here.. could the keyway be off on the VP, causing the timing to be off, but wouldn't it idle bad when cold too....or does the VP change timing when the motor is cold?

The only codes that i have seen, pointed to a bad VP, so it was replaced, i don't remember what they were. There was one code that had something to do with BUS communication, but don't remember the number. Since then, there has not been any codes. i remember now, it had a P1694 code. The more i think about it, could it be a "heat soak" issue with something in the ECM?

I hope you guys will be able to help me out because I'm at a complete loss. So i have 2002 dodge 2500 with 174k and it has a rough idle when the motor is at operating temp. The truck idles just fine when it is cold, only when it is hot does it start idling like s**t. It almost sounds like it is missing, but I don't think it has a miss, I don't know what else there is to replace on this thing, everything is all new. This is a daily driven truck, it does not have a programmer on it, just 100HP injectors, 60/67/12 FPI turbo, 4in exhaust, BHAF, gauges. Here is a list of everything that have been done to the truck in the last 3k miles and it has not solved the problem. New Vp44 about 1k miles ago Air dog 100GPH about 500 miles ago New MAP sensor New IAT sensor New CPS New injectors (100hp DDP) New connector tubes New batteries All new battery cables( cleaned and checked all grounds) New alternator Please let me know if you have any ideas about what this could be, just need ideas about where to start next.... APPS? ECM? Dodge wiring? Thanks,