I took my junkyard injection pump and injectors to the shop to have them tested and rebuilt if necessary. The technician immediately set about removing the advance piston. He said if it had any wear on it at all, he could not guarantee the pump would run correctly. It had just the faintest wear marks and discoloration. He brought out a serviceable one, compared the two and told me mine was trash. Next he took an injector and it popped off around 1450 psi with no spray, just a sputtering stream. The next injector did the same.
Today I picked up my ip and injectors. The tech said the ip was rusty on the top and he had changed out the rusty parts with some he had from cores. He cautioned to flush the fuel system if it was going back in the same truck, which it isn't. He didn't mention anything else in the pump being bad. They gave me some rebuilt exchange injectors and after watching the moose injector video last night I asked him to put a new one on the tester for me. While not the fog pattern like the moose injector, it had a much better pattern than the stock injector in the video. YMMV.
The advance piston is a common wear item, and I don't think I've seen a Moose Pump come out of the shop that didn't need one. This is also an area where a lot of other rebuilders skimp. Stanadyne issues advance pistons in oversize units, and the bore has to be machined to match. If the original piston is the largest size (due to numerous rebuilds) the bore has to be enlarged, and then sleeved down to the smallest size so that the process can repeat. This definitely adds to the cost of a rebuild. Some rebuilders may choose not to do all that work if the largest piston is already in use, or they may opt to replace just the piston with the same size. This causes timing instability and a pump that may not have that many usable miles on it without a problem developing. The work is labor intensive and consequently expensive.
Actually I might take back my comment that he did you straight depending on what he did with the advance piston.
I supposed he could have determined it was Ok or redid it.
I rebuild these pumps and can say I rarely re-use an advance piston. Advance pistons come in .002, .005, .008, & .012 OS. I ream the housing bore to the size that cleans all the marks out. After .012 I trash the housing & replace with a new one. I don't believe in sleeving housings as it creates more problems than it solves.
I rebuild these pumps and can say I rarely re-use an advance piston. Advance pistons come in .002, .005, .008, & .012 OS. I ream the housing bore to the size that cleans all the marks out. After .012 I trash the housing & replace with a new one. I don't believe in sleeving housings as it creates more problems than it solves.
Thank you and that is the way it should be done.
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91 F350 crew cab 4x4 7.3 ats and intercooled with cut down 2000 ps cooler, bigger turbo comp,head studs, torque cam, coated rockers , balanced. very good power.
pyro,boost and all stock guages ignored with mechanical real ones
Fugitive sandrail. type 4 2840 turbo fi, lots of fun
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