What's the best way to clean a DB2 pump without disassembly?

[Rockabillyrat]

Its not going to flow alot out of the return fitting. If it does that would indicate and issue with the pump. Return volume is a combination of fuel making it past moving parts like the H&R and advance pistion, and the the vent wire in the head. If the H&R or advance piston is worn then return volume will increase.

Like I said return spec is measure at 2000rpms for 1min at WOT, with calibration fluid at 110-115*f. With what your doing a very small amount of return is normal.

If your not getting fuel to the injectors it can be a number of things besides sticking parts... did you confirm that the metering valve is moving? Is it making transfer pump pressure when your spinning it with the drill? Those are two easy things to check. Everything else requires some disassembly to check

 

[spdgofast]

I checked the specs on the drill I'm using and it spins 2000 rpm's, I did spin the drill just for about 45 seconds after I installed the transfer pump gauge and it went to 85- 90 lbs. I want to give the ATF a chance to work before I just waste it all running it through at barely a dribble out of the lines. I'm sure my drill is spinning the pump faster than the engine starter does and more than when it's idling IMO.

 

[spdgofast]

Its not going to flow alot out of the return fitting. If it does that would indicate and issue with the pump. Return volume is a combination of fuel making it past moving parts like the H&R and advance pistion, and the the vent wire in the head. If the H&R or advance piston is worn then return volume will increase.

Like I said return spec is measure at 2000rpms for 1min at WOT, with calibration fluid at 110-115*f. With what your doing a very small amount of return is normal.

If your not getting fuel to the injectors it can be a number of things besides sticking parts... did you confirm that the metering valve is moving? Is it making transfer pump pressure when your spinning it with the drill? Those are two easy things to check. Everything else requires some disassembly to check

What causes the metering valve to open? I understand when the FSOS is powered up it allows the metering valve to open and then the spring in the FSOS pushes the metering valve closed when there is no 12 volt power to it therefore shutting the flow of fuel and shutting down the engine. So is it transfer pump pressure that moves the metering valve open?

 

[spdgofast]

Neverminded, I just went and inspected the pump that is working on the engine and I see that the metering valve spring holds it in the run position and the FSOS spring holds it in the off position when not energized. I ran the drill briefly with 5lbs of lift pump pressure the pump housing pressure goes to about 10 lbs then turn on the drill and the transfer pump pressure goes to just over 100 lbs with the throttle closed, with the throttle at WOT the transfer pressure drops to about 60-65 lbs. It looks like I may be getting a hair more flow out of the injector lines but not enough to get excited about. I'll shoot a video some time tomorrow and post it up.

 

[spdgofast]

I have a simple question, if I had 20 lbs of pump housing pressure and I energize cold advance solenoid wouldn't I see a steady flow of fluid out of the fitting on the top of the IP?

 

[Rockabillyrat]

You should never have 20psi of housing pressure. 12psi is max spec. Also just because it's builds pressure dosen't mean its going to flow alot. Pressure is the resistance of flow, even a low return flow can build pressure.

 

[spdgofast]

Hey guys, sorry for no video yet, I've just been busy working on other stuff like a Continental aircraft motor in an airboat. But I have been walking over to the pump about once a day and running it. It is now pumping out about 3/4-1 gallon of ATF in 5 minutes which it wouldn't do that in 30 minutes when I first hooked it up. I will shoot a video of it running approximately a gallon of ATF, then I will switch it to diesel fuel, if things look right with diesel I will then try and run it on my test stand engine.

 

[spdgofast]

Ok guys, I finally shot a video of the DB2 pump flush I'm doing, I'm sorry that the video orientation is 45* off, I'm not the best at shooting video's so just turn your phone or laptop 45* LOL. I will probably be switching to diesel fuel in the next day or so, so we'll see what happens with the fluid change and then what happens when I install the pump on my test stand engine.

 

[spdgofast]

Well I guess my drill trick with the ATF worked, here is the engine running with the same pump that wouldn't run on the engine but after my force feed ATF with the drill cleaned it out.

 

[dbrannon79]

Wow @spdgofast that engine sounds really good!

 

[spdgofast]

It's a Jasper remand fully dressed with the injection pump that cost $6700.00 that sat for 6 years, I plasti gauged the rods and they are all between .001 & .002". I did the ATF with the drill trick and it runs great. I'm going to offer it for sale for $3000.00 fully dressed with Injection pump & water pump with harmonic balancer.