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which fuel pump

Discussion in '40- & 55-Series Tech' started by toddslater, Mar 4, 2007.

  1. toddslater

    toddslater

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    A little background...it's a 76 pig with an 84 2F installed. I have run through ~ one tank of fuel (and 4 fuel filters...starting to clear up..seperate issue) and it has a weber 38 with FP regulator and pressure gauge. The original (1976) set up had no fuel return line associated with the fuel pump. The motor/fuel pump thats in their has the original (came with the 1984 engine) fuel pump with a return line set up. During the initial runnings with the first tank of fuel it would idle and the FP gauge would bounce like crazy from 0-5 psi (coming into the FP reg). It would also fuel starve at any rate of acceleration. Soooo, as an intermediate fix, out came the needle nose vise grips and I clamped the fuel return line (not 100% but enough to stabilize the FP gauge to 4-5 psi). Ran like a champ ..no starvation. That was thru December..and I topped off the tank (and bought a few more filters). I decided that the needle nose vise grips needed to go back in the box, so I blocked the fuel return line in a more permanent fashion. I fired it up a few times in this configuration (replaced a thermostat to get some heat going) and during these times I noticed black schmootz splattering out of my tail pipe...at the time I chalked it off to water/condensation...and it also had some annoying blue smoke. Hmmm, never did that before.

    So today was decent weather and I decided to see whats what. Fired it up...idle was OK, but stumbled on blipping the throttle. Blue smoke was prevalent. Tried to go for a little spin to see if she'd clear herself out. No luck there fuel starved and stumbling and blue smoke. Panic set in...compression is good 145-150 all across. Plugs black and sooty. Pulled the dip stick and oil was thin, overfull and smelled of Sunoco....viola... Fuel pump gone bad dumping gas into the crankcase. Sorry for the length..but now the question. Do I install an old (1976) style fuel pump w/o the return from the FP...or do I install a new style (1984) FP. If I go old style do I need the spacer ? If I go new style, do I block off the fuel return...or is this what made the 84 FP s*** the bed in short order ?
     
  2. Josie'sLandCruiser

    Josie'sLandCruiser Stop calling it a "FJ."

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    Hi All:

    Well, not exactly a straight answer to your question, but hopefully helpful! :D

    A body of mine with a '79 2F ran a Weber carb with the factory Toyota mechanical pump just fine for many years. Sorry, I don't remember if the set-up had a fuel return line or not.

    My rig has a '78 2F using a de-smogged '77 Aisen carb (thanks Jim C.!) with fuel return line and a low-pressure electric fuel pump. It runs just fine.

    But, I would hazard a guess that your problems with acceleration, etc. might be due to crap in the fuel lines (you mention changing fuel filters a lot.) Have you drained and flushed-out the fuel tank yet?

    Good luck!

    Alan
     
  3. grant5127

    grant5127

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    Later fuel pumps with returns wont tolerate the return being blocked off........ spacer is needed on 7/79- up...... and still there are some grey areas.... a test fit is needed to be positive...
     
  4. toddslater

    toddslater

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    I'm leaning towards getting the old style FP (w/no return since it has the weber on it). Otherwise unless someone can confirm the new style should deliver constant fuel pressure to the carb, I'm thinking that it will be seeing the pulsating fuel pressure and that just doesn't cut it with a weber. Thanks for confirming that by blocking the return I made my FP crap the bed :cheers: Kinda thought it was self inflicted :doh: Easy enough to do a side by side look to see if the spacer is needed or not.
     
  5. toddslater

    toddslater

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    Little update...went with the old style fuel pump (ie no return), also running the fuel pressure regulator (2 psi) going into the weber 38. Drained oil and replaced filter...threw in a new fuel filter too. Fired it up and all things except for the blue/gray smoke seemed fine. So, I decided to run it for awhile to see if the smoke would clear (thinking it may have to burn some crude out of there from the gas/oil crankcase mixture). Well, it didn't clear up after a fair amount of running it. Soooo, out comes the compression tester again...still good 145-150 for everyone. Scratch head....and put on the vacuum gauge to see what it says. 21" but not steady..bouncing + or - 2". Hmmm, tech links section on vacuum, points to worn guides (or seals). OK makes sense blue/gray smoke out the tailpipe oil coming down the valve/guide area. I put new stem seals in last night/this AM and have put about 30 miles on it since lunch...smoke at first them after about 5 mins...all smoke disappeared. All is right in pigwald world...at least for a little while. Question is, do you think the gas/oil mixture, that was caused by the fuel pump crapping the bed, also caused the rather abrupt crapping out of the stem seals ? or was it just a coincidence that the stem seals went shortly after the gas/oil mixture in the crankcase was discovered ?