B787 Posted November 22, 2015 Report Share Posted November 22, 2015 Car, a 1998 WRX with Possum Link ECU has been experiencing starting problem, ie unable to start usually in the morning. This morning, after 6-7 long start attempts, the engine just refuse to fire up. Fuel pump priming ok which I always wiat for the fuel prime to complete before turning ignition switch to START. After 2-3 hours, I came back and try to start her up and the minute I turn the ignition switch to ON, there was some sort of weak detonation in the engine which I can feel the engine turn a bit through vibration and some faint pop sound from the exhaust. This is obvious as excess fuel in all the cylinders from previous 6-7 start attempts. After fuel priming completed, I turned the switch to START and she fired up with ease.What puzzled me is why there is detonation in the engine when ignition switch was in the ON position. The spark plug or plugs must be firing to burn the excess fuel. Spark plugs are two months old. This problem of unable to start usually occurs in the morning but it has occur twice when engine was fully warmed up. Problem occurs about 4 months ago. Ignition coil was replaced about 5 years ago. BTW, once she fires up, all normal.Any advice for me to check.Thanks in advance.Cha Quote Link to comment Share on other sites More sharing options...
Simon Posted November 23, 2015 Report Share Posted November 23, 2015 Could be a number of things causing the non start.The pop that you get is the coils can fire at the initial key on due to them getting 12V slightly faster than the ECU can power up. The first thing the ECU does once powered is to turn the coils off which can then cause them to all fire.Ideally you need to get a hand control or PC link connect at the time the engine is not starting.We need to see if it is getting an RPM signal.If you have fuel but no spark this points to a lack of a sync pulse from the sub-board. This could be a faulty cam sensor, broken wire from sensor, connection issue inside the ECU. Quote Link to comment Share on other sites More sharing options...
B787 Posted November 24, 2015 Author Report Share Posted November 24, 2015 Hi Simon,Thanks for the info. My dealer here reckon it could be a faulty cam sensor or a crank sensor but unfortunately they didnt have any in stock. I managed to get a used cam sensor which is now fitted to the car and hopefully starting problem gone. Problem is this is an intermittent fault and will connect up the hand control once problem arise.If this is an connection issue inside the Link ECU, can this be rectified ? Just thinking and planning ahead.Thanks.Chan Quote Link to comment Share on other sites More sharing options...
Simon Posted November 24, 2015 Report Share Posted November 24, 2015 Hi ChanYep we can still service the ECUs if needed. Most of the parts are still available. Quote Link to comment Share on other sites More sharing options...
B787 Posted November 30, 2015 Author Report Share Posted November 30, 2015 Hi Simon,I couldnt start my car again this morning so I hooked up the hand control device to check if RPM signal was avail as per your advice. Once hooked up and powered up, Test RPM showed 000. When I start the engine, with engine still cranking, RPM still show 000. Is this normal or RPM signal is not available ?Thanks. Quote Link to comment Share on other sites More sharing options...
Simon Posted December 1, 2015 Report Share Posted December 1, 2015 At crank you should see around 200-250 RPMNo RPM indicates either crank or cam sensor issues or a connection issue between sensor and ECU or internal issues in the ECU. Quote Link to comment Share on other sites More sharing options...
Matek0012 Posted October 7, 2016 Report Share Posted October 7, 2016 Was this issue ever resolved? Quote Link to comment Share on other sites More sharing options...
B787 Posted October 9, 2016 Author Report Share Posted October 9, 2016 Hi Matek, unfortunately answer is no. I have replaced both the crank and cam sensor and also coolant temperature sensor since my problem is unable to start early in the morning. Even with new cam and crank sensor, I don't see any rpm (zero rpm in the hand control display). RPM appears immediately after a successful start.Do you have a similar problem ?Chan Quote Link to comment Share on other sites More sharing options...
Matek0012 Posted October 10, 2016 Report Share Posted October 10, 2016 I guess you can call it a similar problem in the way that it doesnt wanna start. i Just can get my thing t fire up i have found some hidiously stupid wiring and will b re wirin most of whats under the dash. Look at my post for similar stuff happening. Quote Link to comment Share on other sites More sharing options...
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