1982 xj6 series. I posted a threat before on cranking time but wanted to create a new one for an update.

The car cranks a good 4-5 seconds before starting up after it has been sitting. On a warm start it always starts right up. I noticed i dont hear a noise when turning the key to the on position and wondering if the fuel pump isnt priming. I need to check the return valve and fuel pressure but was wondering first where the fuel pump relay is and how to test it. Not sure how the priming part of the pump works and what that is connected to to activate the prime. After putting the car into 'D' and starting it does start a tad quicker and sounds better to. Better combustion sound, rather then when it starts normally it hesitates for a split second then fires up. Not a huge issue but sometimes i get annoyed how long it cranks and sometimes if i have to crank it twice to start. Spark plugs and wires are new. I see the relays lined up on the firewall, which one is which in order? Is the starter relay located in here to? Starting to wonder about the fuel pump itself that the shop put. They installed one then it gave out in 2 weeks, warranty for another one which has been going for 4 months. Is fuel pressure always suppose to stay at a certain amount when engine off?

 

I'm no expert but my guess is the cold start injector or the temperature sensor that activates it.

The fuel pump anly operates when key turned to start, when the starter is cranking.

Start it in Drive??? Shouldn't be able to do that. .......

 

Simply turning the key "on" does not power-up the pump circuit on your XJ6 The circuit is powered up with the key turned to 'start' and then, after the engine begins to fire, it is powered up via a switch in the air flow meter





There is no 'prime' feature on your car. The V12 models had such a feature but not yours.

The 'put in Drive and turn key to the start position' *is* priming the system





A tad quicker might be as good as it gets. These engine usually do not start instantly




Pressure should hold for a long time because of the one-way valve. But, even if the pressure bleeds down, a good fuel pump will recharge the fuel lines very fast....like about 2 seconds, maybe 3 seconds at the most.

The only way to check this is with a fuel pressure gauge

As for checking the fuel pump relay, well, the engine runs.....so the relay is working.

Cheers
DD

 

One of the entries in this write-up covers the firewall relays:

Quick Reference: Top Twenty XJ Repair Issues



Info on checking the fuel pump circuit:

Fuel Pump Circuit Checklist


Cheers
DD