DDP Injectors Need help!!!

[PaulJohnson]

I install my 50HP DDP injectors today... ... . I sent my stock injectors to them and they honed my stock tips out to 50hp. Installed them, started the truck and drove it to the end of the block and was pretty happy with the power increase. Got of the truck and a loud Hissing sound was coming from under the truck. i crawled under and the sound was coming from the Fuel tank vent hose on top of the tank. I removed the fuel cap and there was a LOT of pressure behind it. Started the truck up again and there is a initial "knock" on start up then it goes away, and a lot of gray smoke. I shut the truck off again and the hissing was back. I called DDP tech support and all they can offer is take it to the dealer. What could be wrong???? I mean obviously pressure is blowing back through the return line and pressuring the tank, but how?

 

[SRadke]

If you had a leak at a crossover tube you would have excessive return fuel. Did you snug the crossover tubes before tightening injector hold down bolts so the injectors could align themselves?

-Scott

 

[sag2]

Leave off or have two copper washers on the injector? Look up my post "injector install with photos" and make sure you followed the torque sequence when you installed them. It does sound like you are leaking compression past the copper injector seal into the fuel return in the head.

 

[PaulJohnson]

I took everything back apart and inspected for a cut or lost O-ring and they all looked very good. Then I seen it... ... . I couldn't last night due to the oil that pooled up on top of the head but since it sat over night the oil had drain back to the oil pan. One lone copper washer sitting between the rocker arms. I pulled #6 injector and yup! no washer. Put it all back together and she runnin fine!!! Just thought you guys would want to know... ... thanks for all your help!

 

[1965LONEWOLF]

How much did you pay for the new ones and do you have the old ones for sale ?

 

[PaulJohnson]

How much did you pay for the new ones and do you have the old ones for sale ?

I paid 50. 00 a injector for mine. I do have a complete set of stock nozzles in my tool box if you are interested... .

 

[sag2]

Don't you just hate it when it's the last one you pull out, and it's the hardest to get to!

 

[1965LONEWOLF]

i wanted to get the ones you had honed out , not the stock ones.

could you tell the extra 50 hp ?

 

[PaulJohnson]

i wanted to get the ones you had honed out , not the stock ones.

could you tell the extra 50 hp ?

I can tell the extra 50hp, but what I notice mostly was how smooth the idle is now.

 

[1965LONEWOLF]

Do you still have the ones that you had honed out ? Are they now rated at 50 hp ?

 

[JMusso]

I think those are installed on his truck.