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Hi all, thought I'd get this done and then post but ran into a few questions:
'89 NA. Car suddenly got very weak, pulled only in a narrow RPM range, 1200-1550, then if you could feather it up above 2000, would run in a narrow range up there.
For a while was still putt-putting around town while I worked on figuring it out, but it got so bad I couldn't keep it up.
I have decided it must be the fuel pump. I made my own fuel pressure gauge, from a Sunpro oil pressure gauge, hooked into a banjo bolt I drilled out, first to 1/8", then 1/4", then 5/16", then tapped it with 1/8" MPT, screwed in the oil pressure gauge fitting. Shows 20 lbs.
I was gonna test with and maybe install a spare-parts pump I pulled from a '96 9000, but it turned out to have seized up while sitting. So I just made the plunge and a new Walbro insert came late today US Parcel Post from Eeuro, $69.95 counting shipping.
All the white plastic (nylon?) parts on my '89 are dark brown, the nylon filter screen is a dirty gray. I cleaned it up with dish soap and water, to get some fine sand off outside of bottom screen. I find, once it's dry, the round screen at basket bottom barely will pass air if I blow hard thru it. And the side panels aren't much better. It would seem, built up varnish over the years makes the pump work harder when fuel is so low in tank that it's not coming in the side panels.
I'm actually switching over the canister and filter basket with lower rubber mount from my '96 9000 pump, identical parts, still like-new white and screen white too, and passes more air.
Any ideas on some solvent that would clean that filter screen, for anyone who hasn't got a newer one to swap? I tried Lysol Kitchen Cleaner and I think it helped some; may try rubbing alcohol before I stow the old parts.
Anyway my question is about the fuel pickup scavenger rig. On the 900 they had it taking the RETURN from the fitting at top. On the 9000 I guess they re-thought things. The RETURN runs straight down into the pump canister, wide open. The PRESSURE line has a tee in it after the pump, half the flow runs to the scavenger fitting, the other half to the pressure outlet, to motor.
Does anyone know if the 9000 setup proved better and is what you get now if you order a complete pump for a C900?
I'd have swapped over but it involves cutting two pressed-on lines and somehow re-installing them, no picnic even if you splice with hipressure fuel hose and clamps.
I find the C900 return line setup offers a lot of resistance to breath if I blow into it. Could that be blockage, or is the returning fuel forced thru a narrow venturi to create a jet flow that helps suck fresh fuel in?
On the 9000 setup, I couldn't get air through the scavenger rig, no matter how hard I blew. (It's a different part no. from C900 one.) Obviously, it needs to have pretty high resistance or the fuel pump's entire pressure would choose to flow that way instead of to the motor and FPR.
posted by 71.173.65...
, Sat, 16 Aug 2014 21:43:17
, Tue, 19 Aug 2014 11:12:40
, Sat, 16 Aug 2014 17:28:59
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