Engine Knock after new injectors

[hackengineering]

I have an 06 that i just picked up about a month ago. Befor i installed injectors there was no knock what so ever. The injectors were shot and i replaced them with some 60hp II. Injectors fixed alot of the issues i was having including poor/no starts and surging while cruise was on. Right after i installed the injectors i had a very deffinet knock befor the turbo spooled at 1200-1800rpms. This happens in each gear under 1800rpm's. I have spend days looking at forums and threads and i see hundereds of comments about this with no real awnser. There has to be a reason after injectors are installed people are getting this knock. One other thing this knock only shows up after the engine is at full operating temp. When it is cool it sounds great. Which leads me to think the timing is being retarded until a specific temp and then something goes wrong. From what i can see there is not a box or anything else installed on the truck. Engine runs great, fuel milage seems decent. I did call II and they said they can not say much until i have some fuel pressures. I have a gauge coming and i should have it in next week.

Of all the threads i have read there has not been any solutions posted.

If you have an suggestions or if anyone found a solution please let me know.

thanks

CH

 

[TCDiesel]

CH. If You Purchase the Injectors from Us PLEASE feel free to contact Me...

 

[cerberusiam]

One other thing this knock only shows up after the engine is at full operating temp. When it is cool it sounds great.

Timing and event shape are both different after engine is up to temp.



What has cured the knock is running the snot out of it towing heavy, if thats possible. Generally that works for a carboned tip but obviously not in your case. You could simply have deposits on the pistons that are causing pre-ignition, or, it could be the shape of the injection stream combined with the timing at low rpms that is causing it.





A good dosing with Power Service and a heavy hot run towing does wonders for these engines at times.

 

[Walcott]

injector knock

I too have just installed new injectors and have the stinking knock,truck runs great and idles smooth. I hooked the skidsteer and trailer(10500) and hit the road,it does seem to have helped but not completely. Somebody has got to have a fix. Comon fellas we need some help.

 

[hackengineering]

I think i would understand this if it just came after some driving or a poor tank of fuel but it is abosolutly right after the injectors were installed, and it also is completly quite when the truck is cold. It also noticed it does not have as much to do with the rpm's as much as the truck spooling. I drove it and the noise disapears once the truck boosts even a small amount. It really seems Computer timing related to me, somehow the engine thinks its getting hot and retards the timing or the MAP sensor is sending a signal of high pressure befor the turbo spools, beats me, i just see alot of posts about this and hoped for that magic solution.



Todd, i will give you a call as soon as i am around the truck again. Thanks again for all your help.

 

[Wingate]

Are all of these knock situations after installing the same aftermarket injector? It could just be the adjusted fueling thats causing a slight fuel knock unitl the engine gets up to speed/load. It also seems possible that many of the aftermarket parts that are available today get simply re-badged from a 3rd party source. . So various dealers injectors may actually be the same part.

Typically, fuel timing is altered unitl a diesel engine reaches a pre-determined temperature set-point. This all started back at the end of the Tier1 emissions era shifting into the Tier 2 emissions days.

Has anybody tried to alter the fuel timing/pressure at low idle to see if it goes away?

 

[wcjp]

Are you sure there's no programmer on the "new" truck?

 

[hackengineering]

Are you sure there's no programmer on the "new" truck?

There is nothing physically attached ie. through map sensor or ecm, it is quite possible someone had an obd programer like a smarty on this truck but i really have no way to tell. and like i said the knocking started after the install and not a hint befor. I have a feeling somthing was at one time attached because my OBD II reader does not report the VIN number from the truck. From what i know some of the programers delete those.