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+--- Thread: loud clatter or knock at cold temp (/showthread.php?tid=4162)
loud clatter or knock at cold temp - DirtDiesel - 12-10-2012
so i got stuck the other day. i had the little girl floor bound and high reved a bit. the day after that i go to start it and it makes a terrible noise until shes warm. performance doesnt seem to have changed. when i give a little rev it seems to quiet a little and when its warm its like it never happened. thoughts?
RE: loud clatter or knock at cold temp - Simpler=Better - 12-10-2012
Injectors that aren't operating properly or an IP timing issue. Since it goes away when warm I'm leaning toward the injectors
RE: loud clatter or knock at cold temp - DirtDiesel - 12-10-2012
so if it is the injectors does greazzer or anybody do larger injectors for more fuel delivery?
also does this render my car inoperable
RE: loud clatter or knock at cold temp - Simpler=Better - 12-10-2012
As far as I know there aren't really any larger nozzles available. if you want more fuel you need to look into the pump, but greazzer/om616 are the guys to answer that one
I don't think it should strand you, just let it warm up before driving under a load.
RE: loud clatter or knock at cold temp - DirtDiesel - 12-10-2012
thanks for your quick response. are nozzles something a machine shop could open up by just a tiny? i will be turning up my pump as soon as i can get some gauges and build me some relocation plates for my oil filter. i just figured it would be nice if i have to replace them to look at the oppurtunity of getting slightly larger ones while i have these ones out.
RE: loud clatter or knock at cold temp - Torkey - 12-10-2012
(12-10-2012, 03:25 PM)DirtDiesel thanks for your quick response. are nozzles something a machine shop could open up by just a tiny? i will be turning up my pump as soon as i can get some gauges and build me some relocation plates for my oil filter. i just figured it would be nice if i have to replace them to look at the oppurtunity of getting slightly larger ones while i have these ones out.Some diesel shops can hone the injectors to increase the amount of fuel.
https://www.dynomitediesel.com/Technology/TheHoningProcess/Default.aspx
RE: loud clatter or knock at cold temp - DirtDiesel - 12-11-2012
is it correct to say our injectors have only one orifice on the tip pointing straight out? the website says that the honing has so much better spacing than the edm. but with a single orifice that wouldnt matter. please correct me if im speaking madness but is drilling a hole that a few thou oversized too crude of a process with very fine sandpaper i would imagine somebody could do a pretty decent job of removing burrs. but maybe theres something to this science i am missing. but it seems pretty simple to be able to chuck up in a lathe and center it. thoughts?
RE: loud clatter or knock at cold temp - larsalan - 12-11-2012
it is sounding like madness to me. It is sounding as if you havent laid eyes on an injector. The pintle or tip or whatever is like the size of a tiny needle.
RE: loud clatter or knock at cold temp - DirtDiesel - 12-11-2012
any idea on the size exactly?
RE: loud clatter or knock at cold temp - larsalan - 12-11-2012
I dunno. Someone can give you the exact spec. I think it is like you can barely see the hole with your eyes. As in no magnifying glass. I have no idea how you could reasonably modify 5 of them to an equal amount.
best start to modify the pump. Push more fuel to them harder or whatever. There is a whole thread on that.
RE: loud clatter or knock at cold temp - Simpler=Better - 12-11-2012
(12-11-2012, 01:05 AM)DirtDiesel is it correct to say our injectors have only one orifice on the tip pointing straight out? the website says that the honing has so much better spacing than the edm. but with a single orifice that wouldnt matter. please correct me if im speaking madness but is drilling a hole that a few thou oversized too crude of a process with very fine sandpaper i would imagine somebody could do a pretty decent job of removing burrs. but maybe theres something to this science i am missing. but it seems pretty simple to be able to chuck up in a lathe and center it. thoughts?
I understand where you're coming from (I'm willing to bet you have modified carb jets before) but like larsalan said the injector is a bit too small/ precise to be modified at home reliably.
RE: loud clatter or knock at cold temp - DirtDiesel - 12-11-2012
this will be done in a machine shop. what im getting at is if somebody cant drill it then how did they do it on the websit torkey listed?
RE: loud clatter or knock at cold temp - Simpler=Better - 12-11-2012
Those are multi-hole injectors. The 617 uses a single hole nozzles with a pintle in it.
You can probably get them extrude honed (they push a fine grit abrasive through the injector)
Can't make claims either way for power gains
RE: loud clatter or knock at cold temp - JustPassinThru - 12-11-2012
I just had this identical symptom start on my '83 300D, immediately upon swapping-in a set of 5 used injectors. They are not rebuilt, just tested for pop pressure, and for no leakage, and checked to see good spray patterns. All five pop a little high, around 2050-2075 and one at 2100 psi. Could it be,...that the 2100 psi one is popping late enough that when the engine is cold the exhaust valve starts to open before the fuel charge is finished exploding? I don't know when the last valve adjustment was --possibly not in the last 75,000 miles. I'll adjust the valves later this week and see what happens. Sounds like it's knocking near the front of the engine, but I did not write down which injector I installed in which cylinder.