timing knock?

9712valve

9712valve

Turtle Racer
Joined
Dec 25, 2007
Messages
1,879
after having my truck timed to 22.5* it kinda has this knock to it at idle and if you crack the injection line to the number 1 cylinder it smooths out and doesn't really knock much, is this normal or does it sound like an injector issue, if I pull one injector i'm pulling them all and putting something bigger in maybe a set of sdx 5x.014's. here's a short video I took....the truck drives much smoother now.

also I did search and it mostly answered my question. Thanks in advance.

22.5* video by ryan818 - Photobucket
 
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Run some oil through your tank, see if that helps a little. Mine at 21* doesn't make that sound.
 
sounds like it could be a injector. try swapping that injector for another cylinder and see if the knock follows...
 
well I have some injectors headed my way, hopefully thats all it is.
 
9712valve said:
I put in a set of 7x.012's from lee at contagious diesel, set at 290 bar. here's a video of the trucks idle now. Not sure if this is what its supposed to sound like at idle with 22.5* of timing, haven't really heard many trucks with timing close to this.
22.5* with 7x.012s video by ryan818 - Photobucket
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Sounds pretty good to me.

What concerns you about the sound exactly? What are you afraid it sounds like?
 
I thought it sounded ok, quite a few local people that supposedly know quite a bit more then me, said it sounds like its misfiring and knocking really bad. Not ever hearing a truck with more then 18* of timing, I didn't know what it should sound like. post up a video of your 95 if you don't mind.

hoodstack1.mp4 video by ryan818 - Photobucket

here's a video of it running....the afc housing and plate in the stock position is probably the reason for low smoke.
 
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Take a heat reading from each cylinder on the exhaust manifold, sounds like you have a cold cylinder. Three main causes, 1: failing plunger 2: injector 3: delivery valve not sealing. Does it always do it, or only when warm?
 
Smokem said:
Take a heat reading from each cylinder on the exhaust manifold, sounds like you have a cold cylinder. Three main causes, 1: failing plunger 2: injector 3: delivery valve not sealing. Does it always do it, or only when warm?
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It does this all the time. The injectors were new when I installed them back in november, The injection pump was all stock when I got it at 249k now im at 251k, so maybe a plunger could be failing, or delivery valve not sealing. and the reason a delivery valve wouldn't seal would be a fine piece of dirt, or something fell in there at some point throughout the timing process or something. I didn't time it so I don't know but, The guy I have time it has done other trucks for me and they always come back fine, and it was doing this on stock timing, but adding timing seemed to help the issue. what is the best temp. to take the heat reading?
 
9712valve said:
what is the best temp. to take the heat reading?
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Cold, after you start it, check the temperatures periodically as the engine warms up. I'm sure you'll see #1 ~ 30° colder, then you can run down which part is causing the issue.
 
9712valve said:
I thought it sounded ok, quite a few local people that supposedly know quite a bit more then me, said it sounds like its misfiring and knocking really bad. Not ever hearing a truck with more then 18* of timing, I didn't know what it should sound like. post up a video of your 95 if you don't mind.

hoodstack1.mp4 video by ryan818 - Photobucket

here's a video of it running....the afc housing and plate in the stock position is probably the reason for low smoke.
Click to expand...

In the hood stack video it does sound like a minor misfire.

Does it still have stock 131 DV's?

I'm in the middle of building twins on my 95 so it is currently not operable or I'd definitely post up a video of 25* with 5x.018's.
 
Big Blue24 said:
In the hood stack video it does sound like a minor misfire.

Does it still have stock 131 DV's?

I'm in the middle of building twins on my 95 so it is currently not operable or I'd definitely post up a video of 25* with 5x.018's.
Click to expand...

The truck is a 96 so its a 180 pump but no the stock 181's were removed a long time ago for the ddp's 024s
 
K204DR said:
any chance that has the copper washers under the dv valves?
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didn't see any when I swapped in the delivery valves, but if I can use one of my buddies shop's ill check. as we have 2ft of snow and its below freezing here.
 
Sounds like its missing, check temp with a heat gun like Smokem said. Or start cracking lines
 
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