Diagnostic Help

[kw0n3k]

Hi all,

well to start off with got this problem with an eg civic fuel injected.....problem comes randomly.

narrowed it down to the engine management relay, it doesnt click when u first turn the key on acc. and it doenst click the 2nd time, engine light stays on.
shorted out the diagnostic plug but no codes....test for spark and theres spark, compression is fine too.

now, put a brand spanka relay on, still no clicks, no power to fuel pump.
anyways its not always like this, some days u can start it fine as if there wasnt a problem at all, have two clicks, 1st click feeds power to fuel pump, 2nd click shuts it off as it should.

now any ideas what will cause the relay not to function correctly? tried a new relay and still no go.

anyways any help will be greatly appreciated.

[chowdaa]

Check ECU fuse 15A (under bonnet), ACG fuse 15A (under dash), if all ok, switch on ignition, as the engine light still lit, disconnect one of the following to see if the light goes out - Map sensor or Throttle position sensor. If it does replace sensor and try starting. There are other checks to be made but using a multimeter.
Possible ECU issue. you sound like you are pretty handy on the tools, may i suggest following the trouble shooting flow chart from the USDM civic workshop manual pdf file, basic instruction for checking voltages.