[02Sleeper]

A couple of weeks ago I posted I have a 96 12 valve that was knocking. I cracked injectors one at a time and found # 6 to make the knock go away. I was going to swap injectors around to see if the noise followed but decided with 225k on the clock new injectors were in order anyways.
Fast forward, the new injectors are in and truck still has a knock on # 6 but it will go away when you crack the line.
I will get guages on it in the near future to see what the fuel pressure is but I am assuming it is good as the truck pulls really hard through all RPM ranges.

P-pump next step, or what? could a weak pump or bad return affect only one injector? the truck runs perfect and idles smooth.

If it is something in the pumo on # 6 is there anything that can be checked or done with the pump in the truck?

I am tempted just just let my son live with it but it bothers me a lot.

Thanks in advance,

David

 

[Haden]

If it were me, I would try narrowing it down even further by swapping delivery valves and then seeing if the problem swapped injectors. Sounds like something isn't popping right and it apparently isn't the injectors so you trace it back to the delivery valves, just unscrew it and swap everything above the big spacer with another one, then you will know if something there is bad. If it's still 6, then you might have plunger issues.

 

[02Sleeper]

If it were me, I would try narrowing it down even further by swapping delivery valves and then seeing if the problem swapped injectors. Sounds like something isn't popping right and it apparently isn't the injectors so you trace it back to the delivery valves, just unscrew it and swap everything above the big spacer with another one, then you will know if something there is bad. If it's still 6, then you might have plunger issues.

Thank you.

Is there anything special I need to pay attention to when swapping the delivery valves? Is it as simple as removing the 2 nuts and pulling the guts out? Any special oreintation I need to watch for?

I forgot to add I checked the valves on #6 today and everything was in spec. I loosen the fule line and the knock completely goes away.
I moved around listening to it with a dowel rod and it sounds like the noise is loudest at the pan. From the top everything sounds great. If your waling around the truck it is loudest behind the drivers door at the bed and same on the passenger side.
I really do not want to get into pulling and rebuilding the pump if it could be a rod bearing or piston noise.
I would think if it was a rod or something the noise would not go away when the fuel is removed but then what do I know.

Thoughts????

 

[Haden]

I have to go to work, do NOT touch those 2 nuts! That is the barrel, what you want is just the thing above that with the 26 tooth or something socket. I will show you in full detail when I get back this afternoon. Those 2 nuts should never be touched though because that barrel is calibrated from the factory.

 

[Haden]

Yeah just ignore this post

 

[02Sleeper]

Got it. Looks easy enough. I appreciate the link. Pictures and videos are work their weight in gold. I will swap them around today to see what I get. Hopefully it is in the DV. I am assuming those can be bought individually somewhere?

 

[Haden]

Yeah search for 181 delivery valves since I think you have the 215 truck and thats the OEM size on those.

 

[GAmes]

You don't need the million dollar socket, vise grips or channel locks work but you will screw those points up in the process and you won't be able to tighten it very easily.

For those of us who believe in using the proper tool. how do you go about retorquing the delivery valve holder to 29 LB/Ft then to 85 LB/FT? "Screw those points up"? Well !!

This is the entire timing process, but the CORRECT way to remove and reinstall the holders is included. TSB 18-10-94 Rev. A

 

[02Sleeper]

OK well I tore it down today with the exception of the DV. All I managed to do was round off the nut and make a mess of it. I need the truck tomorrow so I was not willing to really crank on it and chance destroying the nut and not be able to get it back together.

Now for the good news of sorts. I was searching the net and saw where a guy said to rotate all of the dv assembles to the right to advance the injector timing and gain power. Well I'm not looking to mess with them and get them way out of whack. So i marked the placement of #6 carefully and loosened the 2 hold down nuts and rotated the valve all the way left. Started the truck and the noise was gone but the truck idled rough and missed at all RPMS. I moved it back right a little and the idle smoothed up and the noise is very faint now. I can live with that. The truck is slightly rougher than before but dosent sound like a rod is about to come out the side.
I can live with that until I can find the socket and replacement cap.


I realize messing with the timing of a single injector is the wrong thing to do but sometimes you have to do what you have to do to make it work.

I was afraid to check but from the look of them it looks like all of them are cranked right. I wonder if the PO read the same thing and messed with it. Every other free power mod has been done to it.


Thoughts?