TwedleJoe Posted October 15, 2015 Share Posted October 15, 2015 So, been having some odd things happened with wondering idle (unplug/re-plug ECU and it resolves) and most recently, dying on idle until the engine warms up quite a bit (idles around 1300 RPM normally). Been sorting these mechanically and now having a more serious problem. Tried to fire up the car today and nothing. When I turn the key to "on", I can hear the relay(s) in the TRW multi-function relay unit click but the fuel pump does not come on and prime. Then, when I turn the ignition to "start" I can hear the additional relay(s) in the MFRU click but no starter turn over. I have checked the fuses, battery voltage, and have power to all other dash, lights, gauges, etc. 2.0 Duratec in a 2012 R400 SV. Any suggestions on where to start my troubleshooting? Link to comment Share on other sites More sharing options...
maurice1 Posted October 16, 2015 Share Posted October 16, 2015 Try checking your battery condition when your are trying to start your car, e.g. under load. It sounds like your battery is failing under load. Have you tried another battery, not jumper leads. Maurice Link to comment Share on other sites More sharing options...
Off Road SHO Posted October 16, 2015 Share Posted October 16, 2015 Or a loose ground where the Negative battery cable attaches to Frame or the smaller ground wires that ground the ECU or relay pack. A lot of times people have a great battery, just poor connections. Tom Link to comment Share on other sites More sharing options...
TwedleJoe Posted October 16, 2015 Author Share Posted October 16, 2015 Thanks Maurice. Checked the battery both voltage and amperage. Voltage stays well north of 12V even when key is turned to start. Low amperage draw when key is turned to run and nothing additional at start position. Look like something else is either preventing the start circuit to complete or it is otherwise open somewhere. Link to comment Share on other sites More sharing options...
TwedleJoe Posted October 16, 2015 Author Share Posted October 16, 2015 Thanks Off Road SHO I have checked al the grounds (battery to frame, at starter, and at chassis harness). All are tight but will actually ohm them out to ensure completeness. Link to comment Share on other sites More sharing options...
TwedleJoe Posted October 16, 2015 Author Share Posted October 16, 2015 I am going to run jumpers to the fuel pump to make sure it is mechanically sound. After that I will start jumping (fused jumper) around relays and connectors to get power to, first the fuel pump then, the starter in an attempt to isolate the section that may be causing the problem. Question...........All I have are the wiring harness diagrams in my build book and they lack much for detail. Not being familiar with an ECU with a MFRU add-on, I wonder if the ECU "reads" the fact the relays/circuits for the fuel pump and/or starter are engaged or if the ECU "allows" the fuel pump and/or starter circuits to complete. Link to comment Share on other sites More sharing options...
DaveStruve Posted October 16, 2015 Share Posted October 16, 2015 Alternator? I had some similar symptoms with miata motor. Idle was hunting, the engine would shut off randomly. Turns out my alternator wasn't working at all or occasionally, the battery would read 12v regardless of engine running or not, when it should have read 14 when running. So after a while the battery would slowly drain, and once it got below a certain voltage the computer would start having issues because of lack of necessary voltage. This also caused my battery going bad as well. Link to comment Share on other sites More sharing options...
TwedleJoe Posted October 16, 2015 Author Share Posted October 16, 2015 Have I mentioned how much it hate spade connectors. Right where the engine loom and chassis wiring harness come together, there is a spade connector in a big, purple, main power wire. It is disguised inside a pretty, round plastic holder that even has water tight rubber plugs in the ends. But, it is nothing more than a spade connector that flops around inside the housing. It must have worked loose causing the intermittent problems and ultimately became terminal when it finally cam all the way apart. Will post some pictures in the morning........ Thanks for all of the advice. Link to comment Share on other sites More sharing options...
TwedleJoe Posted October 17, 2015 Author Share Posted October 17, 2015 Not sure if this was Caterham's doing or if my builder did it but if you have one of these replace it! Link to comment Share on other sites More sharing options...
jlumba81 Posted October 17, 2015 Share Posted October 17, 2015 (edited) Looks like an inline fuse holder using one of those cylinder type fuses. http://www.orschelnfarmhome.com/20-amp-hd-panel-mount-fuse-holder/ctl16754/cp57937/si5938370/cl1/ http://www.amazon.com/1st-Source-In-line-Fuse-Holder/dp/B0002KR8EE Edited October 17, 2015 by jlumba81 Link to comment Share on other sites More sharing options...
Off Road SHO Posted October 19, 2015 Share Posted October 19, 2015 That could also be a sureptitious though poorly thought out anti-theft device. Tom Link to comment Share on other sites More sharing options...
Wings Aviation Posted October 22, 2015 Share Posted October 22, 2015 Oh yeh, that "immobilizer" only ever immobilized me....... I no longer have it, however I do remember that removing it wasn't as straight forward as it should be. I don't have any of the old Caterham electrics, but there is some funky stuff in there. If you can't get it figured out, I can give you the number of the guy that got mine sorted out. Link to comment Share on other sites More sharing options...
BruceBe Posted November 3, 2015 Share Posted November 3, 2015 This is standard Caterham. It was probably brutalized during initial assembly - haven't seen particular failures with it. Spade connectors will relax with time - this is a common problem with the connections on the keyed ignition switch as well. -Bruce Link to comment Share on other sites More sharing options...
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