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Is there a way to measure fuel pump pressure???


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1992 ls400.  My service manual says I need a special tool that replaces one of the supply bolts.  Is there a way to check it without the tool?  I tried to remove the fuel filter but the fittings won't budge.  Soaked them in PB blaster, 50/50 acetone and ATF fluid and WD 40 professional penetrating oil.  Nothing works.  Yes, I have rounded the nut and am now forced to try vise grips.  But still won't budge. So is there some other way to measure fuel pressure?  Thanks.

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Have you checked to see if this can be done?

  1. Fuel Pressure Test:

    • Locate the fuel pressure regulator on the intake manifold near the throttle body. It’s usually a small, round component.
    • Remove the fuel line fitting from the regulator.
    • Install a banjo fitting with a longer bolt and attach a fuel pressure gauge to it.
    • Turn the ignition key to the “ON” position (without starting the engine) and observe the pressure reading on the gauge. It should be within the specified range for your vehicle.
    • If the pressure is too low or too high, it could indicate a fuel pump or regulator issue.
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Thanks for your response.  However, I don't have a banjo fitting or a longer bolt.  This sounds  a lot like the special tool I don't have.   See Attached. What I can't believe is they didn't spend the money to put a simple schrader valve in the manifold.  Instead they choose to try and force you to take it to a dealer.  Even my cheap little mazda truck has such a fitting (schrader)  to check pressure.   And don't get me started on where they put the starter.    😞

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I think Toyota tool kit is 09268−45012 EFI Fuel Pressure Gauge.  It comes with the gauge, fittings (banjo and banjo bolts), and hoses.  It appears that this is used on most all Toyota FI engines.

My guess is you're looking at $$$.

You can kluge together a pressure test gauge. It's a lot of work for one-time use.

1) You'll need a banjo fitting of the proper banjo bolt size and hose size that will accept a flared fitting hose:

Untitled_402.jpg.35b51e86d0d9bd17456d74b4a8ba65b0.jpg

2) A double banjo bolt of the proper thread size:

Untitled_401.jpg.33b1bee318ee7b5d26a14a2f3afcb9dc.jpg

3) Copper seal washers of the proper bolt size.

4) A high pressure gauge.

5) Hose to connect the banjo bolt to the gauge.

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Many thanks for your comments.    I bought a new fuel filter for #12 off ebay  and have been trying unsuccessfully to get the old one off.  Once off, my plan is to use a hose on the flared tubing end to measure.  Unfortunately, I've been dosing the old filter in every penetrating oil imaginable for two weeks and it still won't come apart.  Plan B - Junk yards have offered me $330 for the car and that's starting to look pretty good.  I had hoped for $500, but you can't win them all.   My plan at the moment is zero additional dollars unless I can prove it's a fuel pump issue..

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  • 2 weeks later...
Well, I was finally able to get the fuel filter out after 2 weeks of penetrating oil, vice grips and an extra long pair of channel locks.  Put gauge on tubing and pump seems to be putting out 45 psig deadheaded.  According to book this is actually the high end (38-44).  So I think pump is good. Installed new filter today and made no difference. So to recap, checked spark with timing light, replaced coils anyway, removed air filter completely, replaced computer with previously running good spare computer, checked fuel pump pressure, replaced fuel filter.  Only thing I can think of left is maybe mass air flow sensor?  But I would have hoped that would throw a code, and there aren't any codes.  Next stop, junk yard 😥😥😥
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