Join Date: Jul 2006
Location: Valrico Florida
The first test to conduct is the fuel delivery rate. The CIS system finesses the mixture via pressure and opposing pressures. If the deliver is anything less than adequate, every other aspect is potentially influenced. The test is relatively easy if your stock air box is removed because you need to access the plug attached at the front side of the airflow metering device between the fuel distributor and metering plate. Once you have access to this, locate the fuel return line on the left side of the engine bay. It exits the fuel distributor from a hard line visible from the rear and heads to the left. There is a "T" in the line that attaches to the base of the accumulator. While I'm thinking about it, a leaky accumulator will allow supply fuel to bypass your CIS which can also cause undesirable results. The line on the bottom of the accumulator provide somewhere for the fuel to go when it fails, that's it only purpose. I disconnected the line from the bottom of the accumulator and plugged the line itself during the test. The idea is to measure to volume of fuel flowing through the return line to the tank. Once the accumulator has been isolated, locate the connection between the hard line and rubber line and disconnect. I attached a short piece of line here (hard line side) so I could place it in my collection container. I used a .5 liter water bottle for the test. Turn the key on, the pumps should NOT run. Pull the plug previously mentioned loose from the meter box and time how long it takes to fill the .5 liter bottle. You can stop the flow by reconnecting the plug at the appropriate time. A little simple math will determine your delivery rate. Basically, your looking to fill a .5 liter bottle in 10 seconds. I hope this makes sense. Good luck with the test, let me know the results. Once you've eliminated this, we can move on the WUR control pressures.
'77 930 turbo Garretson I/C 1 BAR spring, (2) '82 Triumph Bonneville Royal Wedding Edition
Past rides: '74 914 1.9 liter twin plugged track car, '83 928S, '87 924S, '75 911S w '78 ROW 3.0, '72 911T, '70 911T and various other insignificant domestic examples. Happiness is a grey tailpipe! Turbo lag......it's worth the wait!