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Fuel Injector Testing and Tuning

I got this pressure tester through Amazon. I looked at a bunch in ebay, most of those adds seemed a bit too scammish, with last one in stock, only five left, etc.
My thinking if I had to return it for an exchange, then I’d be out of luck.
At least with Amazon return for exchange or refund I think is a little more reliable.
Many other sources and styles available.

I had read the ratings and many said the one they received had a busted fuel container. Against My better, or most times, worse judgement went and ordered in one.
I arrived and was all intact, except it was missing the shown seal kit and the page of instructions. Sent the company a message, see what happens.
And so I installed the gauge and filled the reservoir. Immediately leaks appeared, again mentioned in the ratings.
Installed one of the tubes that fit one of the old injectors and started pumping on the handle. No results after a couple hundred pumps.
Set the entire affair into a drain pan and called it a night.
Next morning there was enough fuel in the pan to nearly cover the base of the pump. Lifted it and wiped it mostly dry and tried pumping on the handle again. Yes, it built pressure and popped the injector. Did not yet bend any pipes in case I needed to return the entire unit.
IMG_5812.jpeg

And so, My thinking was the small 10mm head bolt in the end of the extension that holds the reservoir, is the securing device to keep the container held to the pump. It is not.
Tried to gently pry the container off and it would not budge.
Pulled off the fuel filter and that stem is the retainer for the tank. Cleaned up a deep well socket, unscrewed that retainer and there is no gasket between the bolt head and the container. Pulled the folgers jug marked sealing washers, seals, gaskets and orings from the shelf. Found a nylon gasket that fit the retainer quite nicely.
Used but not abused. 😹
IMG_5814.jpeg

Put it all back together and that nylon washer fixed the fuel leak.
Then I bent the pipes. I did have a little fear of bending them because the material seemed like it was quite heavy and ridgid. I didnt want to bust one trying to get them bent so the injector would set downwards and into a container.
I asked in the forum, AK Diesel Driver responded with, Bend away. To which I did, with much success.
IMG_5815.jpeg

And so it is set up and ready to go.
If I had enough money I feel I would have went to this one mercedes site and ordered in the pump that they offer. I dont remember the price but it appeared to be of a higher quality and much worth the money.
 
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And so testing injectors.
New Bosch. They all popped right at 1900 PSI with varying minimum leakeag, except, Had two real bad leakers and they wanted to pop well before they got to 1900 PSI. Right around 1400 to 1500 PSI they would sometimes pop or chatter. Sometimes they would got to about 1800 PSI but they were spraying out fuel so fiercely that they would not build enough pressure to pop or chatter.
The first leaker. Keep in mind that while trying to get over that 1400 to 1500 PSI that the injectors are releasing copious amounts of fuel.

And the second real bad leaker.

All in all this presure/pop tester functions just fine and the gauge seems to be accurate enough.
I did have to constantly remind myself to not build pressure quite so fast. The oil filled gauge is a little slow to respond and the needle seems to need catching up with the fast rise of pressure. And so a slightly slower increase of pressure seems to yield more accurate readings.
I did measure the gauge threads. They are not a pipe thread and they dont seem to be a metric nor an American thread and, the diameter is slightly larger than a 5/8ths but smaller than the corresponding metric size, IIRC a 16mm.
The threads do match a metric pitch of 1.50 and also the pitch of one of the American diameters, of like the 5/8ths NF but I dont remember what that pitch is. I will measure when I get back to the garage.
 
I have sent an email to the supplier of the new Bosch injectors, informing My request to return all 8 and wanting to go a different route, with a different injector and set up to supposedly marine standards.
I requested some info from them about warranty if I have tested them and find that some or all are faulty if a full refund, without question, will be given.
We shall see.
I am hoping that this next set of injectors are shimmed to pop at around that 2300 PSI range.
Or at least above 2000.
 
The gauge threads are most likely British standard if not metric. if you want a better gauge on it, you might take the pump or gauge down to a hydraulic shop to match up the threads. I am sure you can get an adapter from it to normal NPT thread.

on the jar your have the injector sitting over, cut you a hole out for the lid just large enough for the threads of the injector to fit through. that will eliminate most of the mist getting out into your work area. or just make sure your in a well ventilated area so you don't inhale the diesel mist or it ignite.
 
When a long time ago I made a homemade stand for the DS4 pump, I connected the FSD, used the optical sensor of the pump as a pulse generator for the FSD. Pump rotated by electric drill.
 
The most important thing is to give an impulse to the FSD in time so that it opens the IP dosing valve. The pump has two optical sensors and a wheel with two rows of slots. I took the signal from the Low resolution CAM sensor (pin B). The output signal of this sensor is implemented according to a common collector circuit, so you need to pull this signal up to + 5 volts through a resistor of about 10 kOm. And already apply this signal to the input of the FSD(pin A).
 
denata said:
The most important thing is to give an impulse to the FSD in time so that it opens the IP dosing valve. The pump has two optical sensors and a wheel with two rows of slots. I took the signal from the Low resolution CAM sensor (pin B). The output signal of this sensor is implemented according to a common collector circuit, so you need to pull this signal up to + 5 volts through a resistor of about 10 kOm. And already apply this signal to the input of the FSD(pin A).
Click to expand...
In My scenario.
I disconnected the IP that is mounted to the engine.
Disconnected the CPS and Hooked all the wires to the spare IP. Used a spare LP to feed hydraulic jack oil to the spare IP.
Using a drill, ignition switch of the truck to run position, and, used a drill and spun the IP shaft in a counter clockwise rotation.
Which I would believe should be the proper direction, being the IP gear is being driven from the clock wise rotation of the cam sprocket.
It would not feed through the IP. That was after about a half an hour of spinning the IP with the drill.
 
Rockabillyrat said:
I built a pop tester and have done quite a few sets of injectors already. In my experience you want to build pressure fast and look for them to chatter at the desired pop pressure. Then slowly build pressure and look for leaks.

View attachment 80588
Click to expand...
I tried to build a pump using a 4 ton bottle jack. The first one I thought maybe the jack pump was faulty, could get only about 500 PSI. The second jack was a lot newer, about 300 was as high as it would go.
I welded the lift limit hole near the top of the cylinder shut and also the hole drilled through the top nut.
Just could not make either configuration to function.
 
MrMarty51 said:
I tried to build a pump using a 4 ton bottle jack. The first one I thought maybe the jack pump was faulty, could get only about 500 PSI. The second jack was a lot newer, about 300 was as high as it would go.
I welded the lift limit hole near the top of the cylinder shut and also the hole drilled through the top nut.
Just could not make either configuration to function.
Click to expand...
My father came up with this. We made our own ram that eliminated any welding.

20201127_175532.jpg
jrsavoie said:
How was foot control for a porta power work?
Click to expand...
I'm sure that could work.
 
I did once again run the two injectors that to me seem bad.
I have all 8 new Bosch injectors boxed up and in the morning calling a diesel shop over in Glendive. This shop has rebuilt 6.5 pumps for the DOT while I was still working in the shop.
I had previously talked to Him and He said He would test all 8 for $100.00.
Call him in the morning and get his addy and get these sent off and see what results this guy comes up with and what his recommendations will be. Then I will have paper proving My case one way or another. But to Me, these injectors appear to be mighty weak.
I did do an rebend on the injector line and got the injector and gauge closer together. Then did a video of each injector.
Some of these are leaking so bad that the pump can not keep up with the leak down to reach whatever the pop pressure is that these are set at. Near as I can determine it is about 1900 PSI.





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