maigaard Posted October 29, 2009 Share Posted October 29, 2009 Hi, greetings from Sweden. I installed MegaJolt & Edis8 some months ago in an RRC 3.9, 14CUX. Runs great, pulls well, always starts. The problem : When really warm, e.g. after 30 min highway driving or off-roading, the engine dies immediately after a restart. It doesnt stall during driving, but if I turn it off and then restart, it will start up fine, and then immediately die. It always starts again, but I need to give a bit of throttle after it starts to keep it alive. It then settles to a low idle of 500-550rpm. It needs to be really warm for this to happen. If I just start it up from cold and let it idle for 10-15 min, then the idle settles to a more reasonable 650-700rpm. I am running a very slightly modified version of one of the "standard 3.9" maps posted here, I'll post mine once I get it copied over from the laptop in the garage. What should I do in order to raise the idle RPM when warm ? - Do the "setting basic idle" procedure for the 14CUX (havent tried that yet) ? - Cheat the ECU into thinking the AC is on (no AC is fitted) anf let the ECU raise it that way ? - Advance the timing in the 600rpm area ? All temp sensors and the IAC valve are new, they went in with the Megajolt system. A new standard cam was also fitted at that time. /Peter Quote Link to comment Share on other sites More sharing options...
SteveRK Posted October 29, 2009 Share Posted October 29, 2009 This sounds more like the problem is fuel related rather than ignition to me. Try 'spoofing' the fuel temperature sensor by disconnecting it and shorting the connectors with a range of resistors from 300 Ohms up wards. I would also manually check the fuel rail temperature - will get warm within a few minutes of stopping the engine and should then cool down within seconds after re-starting. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 29, 2009 Share Posted October 29, 2009 Can you post a datalog of this problem and your MSQ file? I suspect it's just that the cranking or afterstart enrichment is wrong when it's hot, it might need a bit more fuel or something like that. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 29, 2009 Share Posted October 29, 2009 Can you post a datalog of this problem and your MSQ file? I suspect it's just that the cranking or afterstart enrichment is wrong when it's hot, it might need a bit more fuel or something like that. Mega*JOLT* Fridge, tsk tsk Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted October 29, 2009 Share Posted October 29, 2009 Pfffft fine, MegaJolt. Chances are it's running lean due to the massive new sparks. Quote Link to comment Share on other sites More sharing options...
maigaard Posted October 30, 2009 Author Share Posted October 30, 2009 great tip about the resistors in place of the fuel temp sensor. Will try that out. /Peter Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 30, 2009 Share Posted October 30, 2009 I'd be checking your base idle and cleaning out the stepper motor extra air valve on the back of the plenum, check the timing manually on the pulley with a timing light and then think about tinkering with the idle advance, could be a mix of all the above. Are you sure the diode arrangement from the coil packs are feeding the ECU properly? Quote Link to comment Share on other sites More sharing options...
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