[T3] Endless Fuel Problems...update...

J. Jonik j_jonik at yahoo.com
Wed Jan 26 15:38:26 PST 2011


I will copy out excerpts from previous replies and add the answers etc.   Answers have >>>>>>>>     Questions, "Q".

Q.   Are all cylinders firing? Check this by pulling one SP wire off the dist cap at a time, to see if the engine slows down the same amount for each cylinder. The gas that goes into a cylinder that doesn't fire may mostly end up in the crankcase. If the engine doesn't slow 
down, that wire leads to a cylinder that isn't firing.  Check the compression on any cylinder that isn't firing. If you have 2 such cylinders, check the SP wiring. You may have 2 SP wires swapped.

>>>>>  All cylinders firing. 
          A while back, all cylinders tested at 127 psi.
            Wires not swapped.

Q.   Do you have the correct '72 pressure sensor? It should have a black plastic cap on the rear end. If you still have the '71 PS, then suck on the hose to make sure it still holds vacuum.

>>>>  Pressure Sensor has black cap.  Months ago I assured that the parts numbers---Control Box and Pressure Sensor---were compatible for this 72 engine and with each other.

Q.    When you turn the key ON (not START) you should hear a relay click and then another click ~1 second later. Do you hear both clicks?

>>>>> Sure....there's the double click. That's been ok all along.
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Q.    Try charging the battery with the ground strap removed. Then let it sit overnight and see if its voltage is low again the next morning. If so, the battery is bad. If not, something in the car is draining it when it's connected.

>>>>>> Haven't done that, but can't, due to weather. Is it important to do this charge while battery is in the car with the plus wire connected?
  Here's 3 days of battery (and VR?) checks:
Day 1:  Battery out of and in car   12.29 v
        Key on                      ?
        Engine idling               13.50 
        Revved                      14.60      

Day 2:  Key off   11.58 v
        Key on    11.41 
        Idling    11.41 to 11.67 (one spike to 12.00)
        Revved    13.60 

Day 3, today:
        Key off   12.12 v          
        Key on    12.02
        Idling    13.91
        Revved    14.79          
 What are the changes about? The weather? Sun spots?
         
Q.    If you understand the concept, you can set your voltmeter to read Amps and connect it between the minus post and the ground strap, and see how much current is there with the car off. It should be almost nothing. The normal draw is just the clock, which is almost insignificant, maybe 30 mA.

>>>>> I used both of my Volt-Ohm meters (old and new), tried at all amp settings, and got zero readings between Negative Battery post and the ground strap. Not even a trace...but clock seems to be frozen. Haven't cleaned it yet.  Hmmm...I should have turned on the radio or wipers or something just to see if amp testing works.
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Q.    I would try removing the fuel line to the cold start injector and plug it with a small bolt and clamp. That would eliminate fuel contamination due to that injector leaking/weeping under pressure. If the problem persists then at least one of the other injectors would be suspect. They can be checked by removing them one at a time and subjecting them to pressure from the fuel line by swapping them out one at a time with a "known" injector that holds pressure. Time consuming and a pain, but worth it to solve the problem.

>>>>>>> Cold start wire and fuel hose have long been disconnected.
The hose has been duly "bolted" and clamped shut. That hose comes in very handy for easy hook-up to Fuel Pressure Gauge.  Can't (re)-do the injector checks in a sleet storm...but no injector leaked, and all sprayed well, when checked etc a few months back. Plus, pulling SP wires showed that all cylinders worked.

NB:  This isn't about just Type 3s...it's about "Senior Citizen" Type 3s...in the plus or minus 40 year old range. Our cars are well over 100, or more, in human years.  The age thing (rust, dried up plastic and rubber, corrosion, dirt, metal wear, etc.) isn't something covered in most (if any) manuals. 





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