While checking the timing as I was troubleshooting the backfiring problem, I wondered if the timing mark plate may have moved. I decided to check if top dead center was really lined up with the 0° advance timing mark. Continue reading “Top Dead Center”
Over-run Valves
Over-run valves were fitted to the XJ12 and XJ-S with D-Jetronic fuel injection to limit vacuum that can be produced when the throttle is closed and engine is at high RPM (such as going down a hill). Without these valves, the engine can backfire in this overrun condition. Continue reading “Over-run Valves”
Backfiring
After all the changes were complete for the vapor lock project, I took the car for drive. It seemed to to go well….I took it up to about 60 mph and then while accelerating it backfired. Drove home and after a while took it out again and upon accelerating from about 25 mph I hear a couple of pops. Back to the garage and start troubleshooting.
Throttle Stand and Linkage Adjustment
I removed the throttle stand assembly and decided to have it bead blasted at the same time as the intake manifolds.
New Fuel Rail Installation
I am finally to the point of installing the new fuel rail. I started with a rail from an HE XJ-S. It was well worn when it arrived so I cleaned it up and sent it off to get zinc oxide plated in the original color.
Intake Manifold Re-installation
I had the intake manifolds glass bead blasted and powder clear coated in a semi-gloss finish. I am happy with the look and they should be much more maintainable.
Fuel Injectors
In 2004 (10k miles ago), I removed all the injectors and sent them in for an ultrasonic cleaning and assessment to The Injector Perfector. After servicing them, he painted them gold (?) and replaced the fuel hose on each. I have read that these early Bosch injectors are pretty reliable, but with all the effort I am going through to improve the fuel system, it made sense to have them checked again.
Fuel Filter Relocation
My main goals for the fuel rail project are to keep the fuel hoses as short and straight as possible and to de-clutter the engine bay. With those goals in mind I decided to relocate the fuel filter to the trunk.
Banjo Bolts
I have good access to the top end while doing my fuel rail project so it is a good time to take care of the banjo bolts. There are four banjo bolts at the back of the engine as shown in the attached picture. At the rear of each head, at the center oil sender pedestal and the lower one just above the oil filter. Continue reading “Banjo Bolts”
Removing Fuel Rail and Intakes
I have started the project to fix the vapor lock problem.