Starting a new thread for this!

Tonight I spent a good three hours working on the fuel system in my '86 XJ6.
I got the fuel pump running, thanks to some helpful instructions from the jag-lovers website. I called a friend over to help me run a few tests.

I had him operate the starter while I listened in back for the fuel pump. It whirred like crazy! Next I had him switch the starter while I pulled plug wires to test for spark. Everything worked out.

In my previous post I explained that I only have one fuel tank on the right side. I wanted the pump to draw clean fuel, so I bought some line and a connector, and ran the line into a jerry can full of gasoline. The pump drew the gas up the line as it should.

The problems: I still don't think the engine is getting any fuel! I jumped the fuel pump to build some pressure, then tried starting it: nothing.

I removed the mass air-flow sensor and sprayed starter fluid down the intake: nothing.

I have fuel, air, and spark? What am I missing here? I'm thinking a new fuel filter is the next step. I bought a glass one today (I wanted to be able to see what was coming through) not realizing I needed one that could withstand a lot of pressure. This one is significantly smaller than the one in the car at the moment. The temperature could be an issue, as it was 35 degrees outside today, and I don't think it's going to get any better for a few weeks.

Any and all help is appreciated!

Dino

 

Check the inertia fuel cutoff switch, located passenger side bottom corner of dash, has a black plastic cover over it. It has a spring button on top, press it down to see if it clicks, in which case it might have tripped like a house breaker, but since the fuel pump runs with ignition switch, I doubt it is tripped.

 

Need confirm fuel arrival at the engine and that the injectors are operating, after you do your filter. Then maybe head scratching can begin.

 

Having fuel to the engine is good, but not good enough to ensure starting.

Agreed on making sure that the injectors are working. Do you hear them click? If so, they are at least fundamentally operational. Next, you need 36 psi regulated fuel pressure. Do you have a pressure gauge?


Cheers
DD

 

You may have a spark at the spark plugs, and fuel in the fuel rail, but the injectors won't fire unless the ECU gets a pulse from the ignition system to trigger the injectors. So you need to check the continuity of the wire from the coil to the ECM. All six injectors fire together twice per engine revolution. The system is analogue with no integrated circuits but works very reliably. It is the various connections and cables that tend to give the trouble.