Injector issues?

[Krlspokane12]

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.

[Me78569]

Ditch ddp and get better injectors.   

[Krlspokane12]

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.

 

Edited March 8, 2021 by Krlspokane12

[Dieselfuture]

They seem to be proud of their injectors, I'd just get a hold of them and see what they got to say. Tell them people like us with cheaper injectors have no issues, what should you do to have no issues. Maybe they will tell you what else you can do to make it right, maybe something is missing in your set up. 

 

[Mopar1973Man]

That is one reason I like DAP injectors I can specify what I want and them built to my specs. Only had 1 set with  issues that DAP gladly rebuilt them again and swapped to VCO from the SAC I had previously. Those were 7 x 0.0085 but popped at 305 bar. Those were just a touch smokey at the end of life which was about 80k miles.

 

My 7 x 0.010 I had built to my specs 320 bar and never once had any issues with starting, smoke or anything. Still going...

[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?

Edited March 8, 2021 by Krlspokane12

[Mopar1973Man]

Hot wire the VP44 and see if there is change to idle performance. If the VP44 is bad it should stay the same if it changes its possible wiring or ECM.

 

[Krlspokane12]

Will do thanks.  If it still runs like crap, should I replace the pump or injectors? I would assume the vp since it ran the same regardless of which

injectors

[dripley]

If everything was running fine before the DDP's, as you mention in the first post, that sure points a big finger at them.

[Krlspokane12]

It was still off at idle, just not as bad.

[dripley]

How long were the previous injectors in the truck?

[Krlspokane12]

3 wks

[dripley]

Was it running fine before that set went in?

[Krlspokane12]

Yes, but the vp was changed and there was something fixed locally in the ecm.

[Mopar1973Man]

This is why I would suggest hot wiring the VP44. If the ECM is the problem it will idle normal with the ECM disconnected. If its the VP44 then the problem will still be there.

[Me78569]

Please remember that DDP historically runs 155* spray angle nozzles.  DDP injectors are historically Smokey and hot.

 

If it quacks like a duck....

 

 

Agree you should hotwire the pump, but my money is on the injectors themselves.   

[Scarecrow]

15 hours ago, Mopar1973Man said:

That is one reason I like DAP injectors I can specify what I want and them built to my specs. Only had 1 set with  issues that DAP gladly rebuilt them again and swapped to VCO from the SAC I had previously. Those were 7 x 0.0085 but popped at 305 bar. Those were just a touch smokey at the end of life which was about 80k miles.

 

My 7 x 0.010 I had built to my specs 320 bar and never once had any issues with starting, smoke or anything. Still going...

Any particular reason you went from SAC to VCO?

 

Mark

[Mopar1973Man]

Smoother idle and operation. 

[Krlspokane12]

Hot wired the pump and nothing changed, so I'm at a loss... I don't wanna blame the injectors since it did the same with the DAPs that were in it. It's gotta be something with the pump but don't know what, there are no codes.

[Me78569]

On 3/7/2021 at 4:57 PM, Krlspokane12 said:

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.

 

 

8 hours ago, Krlspokane12 said:

Hot wired the pump and nothing changed, so I'm at a loss... I don't wanna blame the injectors since it did the same with the DAPs that were in it. It's gotta be something with the pump but don't know what, there are no codes.

 

 

So the issue did or did not exist with the DAP's?