mikeyb10supra Posted November 30, 2009 Share Posted November 30, 2009 Right, I am hopefully starting to get to the bottom of this now. I have just been outside this morning messing with the fuel pump again after the on-going issues ive had after fitting a UK spec pump on my j-spec. Now im a little confused. After testing a few things out, the car now runs fine with the stock fuel pump ECU.....BUT, only without it being earthed. As soon as you earth the fuel pump ECU the car stalls and wont re-start until the earth is removed and then it runs fine again Anyone got any ideas why this would be? Mike Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 30, 2009 Share Posted November 30, 2009 Is it earthed off the loom wiring or its own connection off to the bodywork? -Ian Quote Link to comment Share on other sites More sharing options...
mikeyb10supra Posted November 30, 2009 Author Share Posted November 30, 2009 (edited) Is it earthed off the loom wiring or its own connection off to the bodywork? -Ian I ran a separate one off the body work and tried 2-3 locations and still nothing im stumped as the car works as intended but only when there is no earth. As soon as an earth is added it stumbles, idles very iratically and stalls within 5-6 seconds Ian is there any major issues with it not being earthed? Its bolted to the passenger side wing if thats any help Edited November 30, 2009 by mikeyb10supra (see edit history) Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 30, 2009 Share Posted November 30, 2009 I ran a separate one off the body work and tried 2-3 locations and still nothing im stumped as the car works as intended but only when there is no earth Yeah it sounds like you've got quite a nasty problemette there I'm not au fait with the fuel pump ECU and I'm busy at work, hence me asking rather than looking it up. If it's a loom wired earth I'd hit the wiring diagrams to see if anything else is tapped into that earth wire and see if that works too. And check if it's got a +ve voltage on it etc. It must be earthing somewhere. Adding another earth shouldn't cause probs either unless there is a short or something... Quote Link to comment Share on other sites More sharing options...
mikeyb10supra Posted November 30, 2009 Author Share Posted November 30, 2009 Yeah it sounds like you've got quite a nasty problemette there I'm not au fait with the fuel pump ECU and I'm busy at work, hence me asking rather than looking it up. If it's a loom wired earth I'd hit the wiring diagrams to see if anything else is tapped into that earth wire and see if that works too. And check if it's got a +ve voltage on it etc. It must be earthing somewhere. Adding another earth shouldn't cause probs either unless there is a short or something... Well it splits from the loom to earth the fuel pump ECU and the fuel pump but it splits into two. The fuel pump is earthed ok and runs fine so im thinking its just the FP ECU side thats the issue. A mate suggested it could be a short somewhere and hence is earthing itself through one of the other wires.....im assuming thats not good Quote Link to comment Share on other sites More sharing options...
mikeyb10supra Posted December 1, 2009 Author Share Posted December 1, 2009 Ian I have decided to just ditch the fuel pump ECU and use an aftermarket relay as the stock ecu is just giving me way to many problems. Is there a wire I can use to trigger the relay which would shut off and essentially close the relay in the event of an accident? Someone suggested tapping into the oil pressure switch/light in the dash so when the car stalls the light pops on and cuts out the relay if you get where im coming from and I guess would also act as a fail-safe if I ever did lose oil pressure whilst driving. Quote Link to comment Share on other sites More sharing options...
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