Failed 26 year old original db2, what’s inside? What goes wrong?

Isaac Ristow said:

I was reading this a few days ago and low and behold I started having some very strange issues with my pump I've never heard of or seen I think its related to that advance seizing up. Saturday I was driving along and all the sudden it sounded like my timing advance stuck full advance I pumped the throttle a couple times it went back normal. Sunday was all good until sunday night I was on my way home and it did it again but didn't go back to normal sounds like atleast 20 degrees btdc. No air intrusion, good fuel flow, the timing arm and cam are good on the side of the pump, I unplugged the cold advance just to be sure, I made sure the return line wasn't stopped up or the return fitting on the top of the pump. Another weird part is with the engine off the throttle is normal but with it running it's pushing back and stiff and also very touchy. I'm swapping pumps I guess its sad this pump has low miles on it always instantly started when hot and felt really good its a original pump I believe

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Isaac Ristow said:

I was reading this a few days ago and low and behold I started having some very strange issues with my pump I've never heard of or seen I think its related to that advance seizing up. Saturday I was driving along and all the sudden it sounded like my timing advance stuck full advance I pumped the throttle a couple times it went back normal. Sunday was all good until sunday night I was on my way home and it did it again but didn't go back to normal sounds like atleast 20 degrees btdc. No air intrusion, good fuel flow, the timing arm and cam are good on the side of the pump, I unplugged the cold advance just to be sure, I made sure the return line wasn't stopped up or the return fitting on the top of the pump. Another weird part is with the engine off the throttle is normal but with it running it's pushing back and stiff and also very touchy. I'm swapping pumps I guess its sad this pump has low miles on it always instantly started when hot and felt really good its a original pump I believe

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Laine D said:

That’s what my old pump did!! It scared the crap out of me one time

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Farmer Rock said:

That happened to me over the summer when I was driving.I sprayed the linkages down and it has been fine since.This pump was also rebuilt recently.




Rock

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Thewespaul said:

Which o ring? The advance piston bore seals off the housing to piston fit, no o ring or seal since its under load from the injection cycles on the cam ring.

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Thewespaul said:

When you swap the problematic pump you should pull the 1" advance bore plug out of the passenger side of the pump, remove the cam pin plug on the bottom of the advance bore (1/4" allen), pull the cam pin out and pop the advance piston out the passenger side and inspect it for damage, sounds just like the advance piston sticking in its bore, these are just going to be more and more common problems with these pumps with the dry fuel we are stuck with now.

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