johneich
John, 1983 F250
I think you take out or put in shims to adjust pop pressure, can anybody expand on that? I just bought an injector tester, if it is shims where can they be bought?
John
John
Know how to adjust injector pop? with shims?
- Thread starter johneich
- Start date
i get the shims from used injectors.
usually I turn two sets of used injectors into one good set of used injectors.
usually I turn two sets of used injectors into one good set of used injectors.
DeepRoots
Tug Engineer
take the injector apart.
It's pretty obvious where the shim goes.
once you open it up, you'll notice spring, shim, seat.
Pressure works against the spring to lift the seat. Obviously more shims make the spring tighter, hence more pressure.
Drew
It's pretty obvious where the shim goes.
once you open it up, you'll notice spring, shim, seat.
Pressure works against the spring to lift the seat. Obviously more shims make the spring tighter, hence more pressure.
Drew
You better have a 0 to 1" micrometers to measure the thickness of the shims. IIRC the shims are from .003 to .010. TYP4 can probably tell you how much pressure increase each size shim will give.
From: http://www.thedieselstop.com/contents/getitems.php3?6.9L Injectors
"When doing a pop test, there are four things you want to look for. The first is the pressure at which the injector releases the fuel. This is the nozzle opening pressure. You want the pressure to be between 1800-1950 PSI. The minimum is 1425 PSI. If the pressure is too low, you can add shims (spacers) between the spring inside the injector and the injector body (see "Rebuilding" below). Use shims that are 0.001" (one thousandth of an inch). Each shim should add about 55 psi to the opening pressure. "
Is there a supplier for .001" injector shims?
johneich
John, 1983 F250
I got it now, just where to buy? NAPA?
77f250diesel
Full Access Member
You can try...http://www.usdiesel.com/.
You'll have to give him the specs., id, od and thickness on the shims you want.
If you can't find that info here do a search over on fte for injector shims.
Dennis
You'll have to give him the specs., id, od and thickness on the shims you want.
If you can't find that info here do a search over on fte for injector shims.
Dennis
icanfixall
Official GMM hand model
I got all my shims from the two sets of G codes I have. I have everything from 001 to 30 thousands... They can sometimes be found a better injection pump repair shops.... Or find a shop that has a bunch of junk injectors. Offer them $10.00 for a dozen of them....
bigblue85
Full Access Member
what does adding shims do? does it increase fuel flow? and make that smoke come out on the old 6.9 and 7.3's?
johneich
John, 1983 F250
Big Blue - The shims increase the "pop" pressure, so if you are poping at 1,400 psi (too low), you want to add shims so you pop at 1,900 psi, shims that are 0.001" (one thousandth of an inch) should add about 55 psi to the opening pressure.
John
John
icanfixall
Official GMM hand model
About 1850 is what you want to see. I had my G codes poping at 1950 and I had smoke and low power... They are not a very good injector. So I bought a set of BB codes from typ4 and wow... what a differance.... I have just over 5000 miles on them and will be removing them to check the pop pressure. I will reset any that needs shimming to 1850 +- 25 lbs.... The closer you get them to pop at the better the engine runs because of the injection timing.... Figure an injector poping at 1500 lbs and the rest at 1800 lbs... The low injector will be advanced compared to the higher poping injectors. Just think if that low injector was the number one cylinder your using to time the engine.....
The closer you get them to pop at the better the engine runs because of the injection timing.... Figure an injector poping at 1500 lbs and the rest at 1800 lbs... The low injector will be advanced compared to the higher poping injectors. Just think if that low injector was the number one cylinder your using to time the engine.....
Wow, you just made me really think... maybe I need to check my timing on #1 and #4 cyls to make sure it is the same...
Wow, you just made me really think... maybe I need to check my timing on #1 and #4 cyls to make sure it is the same...
Take the harmonic balancer get it degreed and then you can check every cylinder...maybe degree tape?
johneich
John, 1983 F250
I only know of two others, spray pattern and leak down (holding it just below pop pressure and look for drips) what is the fourth?
