Quote:
Originally Posted by Laird Scooby
A couple of points on your 1990 740, the fuel pump relay passes current to fuse #11 for BOTH fuel pumps - on later 940s it feeds fuses #11 & #13, one for the main fuel pump and the other for the lift (in-tank) pump and Lambda sensor heater. It's worth checking that fuse #13 is intact on yours, just in case yours is a leter 740 with a 940 style electrical system.
Clicking from the relay means it is operating mechanically on the control signal, it doesn't necessarily follow the contacts are passing current to the pumps - hence my test as described above to see if power is reaching the in-tank pump.
Information about the early LH2.4 (as yours is) is a bit hazy about whether it reprimes after the ignition is switched off and then back on again, as Rob says on later models there is a time delay (10 minutes i think) before it primes on first turning the key to position 2 but either way, if the starter runs the engine, it will trigger the pump to run for a second or two after it is released from position 3 - this is normal across the 7/9xx range as long as it's electronic injection.
Run through those tests i outlined and see what you've got. If the tests don't give the results i suggest then let us know. As for the pdf Rob linked to, there are many differences there to how yours is set up, for a start the author claims he has LH2.2 but has a Lambda sensor.  Not for UK models at least, that would be an LH2.4 which yours is. |
Thanks. I've got plenty to work on, so will crack on with those and report back the results.
One extra question. Yesterday I tried to remove the fuse tray and couldn't. I have removed the compartment above the ashtray, and been pushing apart the white clips and lifting up but only the left hand side comes loose. The right hand side seems completely stuck and will not budge at all.
Any tips?