Shifty1962
Well-Known Member
Ok so let me explain because I'm stumped.
Today I noticed that my fuel gauge was reading full despite me not having filled up for a week or two. Yesterday the gauge was reading properly so I knew there was only about a 1/4 tank of fuel. I naturally assumed that either the float was stuck or the wiring had shorted giving the full reading or someone had p*ssed in my tank.
Using my handy fuel pump hatch in the rear floor I unplugged the electrical connector to the pump and float and the gauge immediately returned to zero. Replugged and the gauge went immediately to full thus proving the wiring was OK but possibly the float was stuck or the float arm bent (no idea how this could happen) giving a false reading or the sender was shot. Just to confirm the wiring I unplugged and shorted the gauge connectors at the tank and the gauge once again read full. So far so good and all as expected. All the time I was doing this the engine was running.
I pulled the pump and gave the float level tracks a wipe with thinners, cleaned the filter and on reconnecting the pump the fuel gauge now read as normal with full range when the float was manually operated out of the tank. Problem sorted and refitted the pump. Reconnected the electrics and started the engine and all was well except that the fuel light is on all the time even when the gauge reads full.
However I thought back to when the engine was running whilst the pump was unplugged and decided to experiment. I started the engine and disconnected the fuel pump/sender plug. The engine continued to run and I expected it to stop after a short while due to lack of fuel. 30 minutes later the engine was still running at idle so I decided to drive around the block and see how much longer it would continue to run. After about three miles of normal driving the engine spluttered and eventually died. Reconnected the pump and cycled the ignition until the pump stopped. Disconnected it and drove home with no issues. It then ran for a further 20 minutes until it eventually gave up.
HOW CAN THIS BE? The fuel lines dont seem big enough to hold that much fuel and the fuel needs to be pressurised to fill the injectors.
I'm going to try it again tomorrow and see if I can replicate the results. The only explanation can be that fuel is being syphoned from the tank into the fuel lines by the running engine but as there is no other fuel pump on a TD5 I dont see how this can be happening.
Spooky or what? Any ideas?
Today I noticed that my fuel gauge was reading full despite me not having filled up for a week or two. Yesterday the gauge was reading properly so I knew there was only about a 1/4 tank of fuel. I naturally assumed that either the float was stuck or the wiring had shorted giving the full reading or someone had p*ssed in my tank.
Using my handy fuel pump hatch in the rear floor I unplugged the electrical connector to the pump and float and the gauge immediately returned to zero. Replugged and the gauge went immediately to full thus proving the wiring was OK but possibly the float was stuck or the float arm bent (no idea how this could happen) giving a false reading or the sender was shot. Just to confirm the wiring I unplugged and shorted the gauge connectors at the tank and the gauge once again read full. So far so good and all as expected. All the time I was doing this the engine was running.
I pulled the pump and gave the float level tracks a wipe with thinners, cleaned the filter and on reconnecting the pump the fuel gauge now read as normal with full range when the float was manually operated out of the tank. Problem sorted and refitted the pump. Reconnected the electrics and started the engine and all was well except that the fuel light is on all the time even when the gauge reads full.
However I thought back to when the engine was running whilst the pump was unplugged and decided to experiment. I started the engine and disconnected the fuel pump/sender plug. The engine continued to run and I expected it to stop after a short while due to lack of fuel. 30 minutes later the engine was still running at idle so I decided to drive around the block and see how much longer it would continue to run. After about three miles of normal driving the engine spluttered and eventually died. Reconnected the pump and cycled the ignition until the pump stopped. Disconnected it and drove home with no issues. It then ran for a further 20 minutes until it eventually gave up.
HOW CAN THIS BE? The fuel lines dont seem big enough to hold that much fuel and the fuel needs to be pressurised to fill the injectors.
I'm going to try it again tomorrow and see if I can replicate the results. The only explanation can be that fuel is being syphoned from the tank into the fuel lines by the running engine but as there is no other fuel pump on a TD5 I dont see how this can be happening.
Spooky or what? Any ideas?
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