

| Subject: | CIS pressure tests - now what? |
| From: | Matt Ratto |
| Date: | Sun, 8 Dec 2002 15:58:20 -0800 |
Hi all, still working on the non-starting of my CIS I4 motor I've installed in my Westy. I've tracked the problem to what I think may be an fuel problem. Mike Johnson (another list member) nicely loaned me his CIS pressure test kit, and I ran what tests I could this morning. Here's the results: Running fuel pump tap closed - pressure 4.9 Bar Running fuel pump tap open (connected to control pressure regulator) 1.5 rising to 3.5 (or so) as control pressure regulator warms up (from heater element, not from engine running) These numbers seem consistent with what the manual states. I also turned off the fuel pump and let the system sit in order to check residual pressure. As soon as I turn the pump off, the pressure drops from 4.9 to 2.5 and then over ten minutes or so drops to 1.5 - I didn't watch it after that. While I did this, I pulled an injector and watched it as the fuel pump was running (I wasn't cranking, just jumpered the fuel pump). Without pressing on the air plate, the injector began spraying intermittantly, pulsing with a little squeaking noise. If I turn the mixture screw clockwise (richer) the time between the pulses decreases, but I never get a constant spray. If I move the plate up about an inch, I get a constant spray, but before that it pulses. Also, I checked the fuel pump by pulling the fuel return line and ran it into a 16 oz. container which it filled very quickly. I should also mention that the fuel pump periodically makes a deeper vibrating sound, but that it doesn't seem to change the fuel pressures or the injector pulsing. So I'm thinking two things; either my fuel distributor is bad (though the numbers seem right to me) or my injector lines aren't working properly. I'm thinking the next test is to go the junk yard and grab a good fuel line and see if it the injector pulses when its connected using this. My current lines are made with 200PSI hydraulic line attached to banjo fittings I salvaged from the original fuel lines. I can't feel them swell or pulse if I hold them while the fuel pump is running. Any advice? Matt ------------------------------------- Matt Ratto Ph.D. Candidate University of California, San Diego mratto@ucsd.edu http://communication.ucsd.edu/mratto --------------------------------------
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