Since I bought 40 of the military surplus 6.5 n/a delphi fuel injectors off of egay I needed to reset pop pressure to Turbo specs. N/A pop pressure is:1852.2 psi Turbo is :2087.4. I could have just taken them to the local injection shop and had all 40 reset at a cost of $6-15 each. It could have cost up to $600 to have them reset To what ever their tolerance was that day. I decided to buy a tester and the adjusting shims and do them myself to know that they are set as close as possible. Having the tester also lets me be able to test the injectors in the future and reset if needed.
I had many of the parts needed to make my own tester but was lacking a few key parts. I search on the internet and found a site that sold a tester for mercedes benz diesel cars. They used Bosch injectors. Their tester was $175.Brand new!.I had been looking at used ones on egay that were going for $400 or more and had been well used. So I bought the tester from http://www.mercedessource.com/node/5180
They also sell 2 different shim kits. $128 for a 72 piece kit
Pretty spendy for that small amount of shims. I ended up getting a guys name that post alot on a mercedes forum. He imports injector nozzles and adjusting shims.He's still checking to see if he can get me some high quality german made replacement nozzles for the 6.5. I bought a large 24 size thickness ,12 of each size kit from him for aprox. $280. This kit should last a very long time.I can restock from him also. His name is sean.His e-mail address is:[email protected].
I recieved the tester on thursday and the shims came today. I had a slight problem with the tester. The injector line fitting on the injector end was too small.:mad2: I swapped a injector line from a 6.2 on it and good to go.:thumbsup:
I thought I should play with it some to get familiar with it.I took a couple old bosch injectors from a junked engine to test. I had to make a catch can for the injector to spray into so I used a clear plastic peanut butter jar. I cut a hole in the lid with a hole saw that was slightly larger than the injector.
The first old injector I put on it popped at 1600psi and sprayed a small stream not a cloud of vaporized fuel. Also dripped badly under pressure and after popping. Chances are very good that that injector needed a new nozzle. They can be cleaned and reused some times. New bosch nozzles are only $14 at rockauto. You cant spend much time cleaning a used nozzle for $14. I tried a second used injector and it popped at 1600psi also. This one sprayed much better than the 1st one. Still 500 psi low on pressure.
Ok. Time to get out the new Delphi injectors and see how they do. They seem to be set around 1800 psi. Of the 12 i've done so far the pop pressure right out of the package varied more than 200 psi. Not all that close for "BRAND NEW". The ones I've reset are at 2100psi and are all within 25psi of each other.:thumbsup:
To test each injector I attach it to the high pressure line and close the valve on the pump. Then pump up to 1500 psi fastly then slowly apply pressure after that untill it pops and sprays, watching the pressure gauge the whole time. Then take the injector off the tester after opening the valve on the pump[forgot that step a couple of times:mad2:] Then take the injector apart. The shims are in the very top above the spring and usually stick inside. I have a pick with a hook in the end of it that works pretty well to get the shims out. These injectors all seem to have the same thickness factory shims in them. That's probbly why the pop pressure varied so much. After resetting a couple I would try the mid shim in them 1st to see what direction I needed to go. Each step in thickness raises or lowers the pop pressure 50 psi. I've only used 4 different thickness shims in 12 injectors. The shims vary .05 mm in thickness. You just repeat the process untill they reach the correct popping pressure. It's good to know that the ones going in my engines are set as close as possible.:thumbsup::thumbsup: Got a few pics of the tester and injectors .
I had many of the parts needed to make my own tester but was lacking a few key parts. I search on the internet and found a site that sold a tester for mercedes benz diesel cars. They used Bosch injectors. Their tester was $175.Brand new!.I had been looking at used ones on egay that were going for $400 or more and had been well used. So I bought the tester from http://www.mercedessource.com/node/5180
They also sell 2 different shim kits. $128 for a 72 piece kit
Pretty spendy for that small amount of shims. I ended up getting a guys name that post alot on a mercedes forum. He imports injector nozzles and adjusting shims.He's still checking to see if he can get me some high quality german made replacement nozzles for the 6.5. I bought a large 24 size thickness ,12 of each size kit from him for aprox. $280. This kit should last a very long time.I can restock from him also. His name is sean.His e-mail address is:[email protected].I recieved the tester on thursday and the shims came today. I had a slight problem with the tester. The injector line fitting on the injector end was too small.:mad2: I swapped a injector line from a 6.2 on it and good to go.:thumbsup:
I thought I should play with it some to get familiar with it.I took a couple old bosch injectors from a junked engine to test. I had to make a catch can for the injector to spray into so I used a clear plastic peanut butter jar. I cut a hole in the lid with a hole saw that was slightly larger than the injector.
The first old injector I put on it popped at 1600psi and sprayed a small stream not a cloud of vaporized fuel. Also dripped badly under pressure and after popping. Chances are very good that that injector needed a new nozzle. They can be cleaned and reused some times. New bosch nozzles are only $14 at rockauto. You cant spend much time cleaning a used nozzle for $14. I tried a second used injector and it popped at 1600psi also. This one sprayed much better than the 1st one. Still 500 psi low on pressure.
Ok. Time to get out the new Delphi injectors and see how they do. They seem to be set around 1800 psi. Of the 12 i've done so far the pop pressure right out of the package varied more than 200 psi. Not all that close for "BRAND NEW". The ones I've reset are at 2100psi and are all within 25psi of each other.:thumbsup:
To test each injector I attach it to the high pressure line and close the valve on the pump. Then pump up to 1500 psi fastly then slowly apply pressure after that untill it pops and sprays, watching the pressure gauge the whole time. Then take the injector off the tester after opening the valve on the pump[forgot that step a couple of times
:mad2:] Then take the injector apart. The shims are in the very top above the spring and usually stick inside. I have a pick with a hook in the end of it that works pretty well to get the shims out. These injectors all seem to have the same thickness factory shims in them. That's probbly why the pop pressure varied so much. After resetting a couple I would try the mid shim in them 1st to see what direction I needed to go. Each step in thickness raises or lowers the pop pressure 50 psi. I've only used 4 different thickness shims in 12 injectors. The shims vary .05 mm in thickness. You just repeat the process untill they reach the correct popping pressure. It's good to know that the ones going in my engines are set as close as possible.:thumbsup::thumbsup: Got a few pics of the tester and injectors .
