4bakker Posted March 7, 2010 Share Posted March 7, 2010 Hi, My range rover (1993 3.9 EFI V8 ) cranks, seems to catch on, but won't start. Engine stopped while driving (after 5 minutes) and wouldn't start. Been having stalling problems before when idling (with hot engine) where the tachometer would suddenly drop before the engine died. Have checked the ignition; sparks on all plugs are good. Have had the alternator checked (was suggested because of sudden tachometer drop) but no problem found. There is fuel pressure and the injectors all click on signal. The ECU does not show any sensor problems. Switched the airflow meter with one from a running RR. Kind of out of ideas... Any suggestions on where to look further? Thanks, Onne Quote Link to comment Share on other sites More sharing options...
DC_ Posted March 7, 2010 Share Posted March 7, 2010 Dizzy? Bob weights loose? Sha**ed rotor arm/cap? Quote Link to comment Share on other sites More sharing options...
Bille Posted March 7, 2010 Share Posted March 7, 2010 Hi, My range rover (1993 3.9 EFI V8 ) cranks, seems to catch on, but won't start. Engine stopped while driving (after 5 minutes) and wouldn't start. Been having stalling problems before when idling (with hot engine) where the tachometer would suddenly drop before the engine died. Have checked the ignition; sparks on all plugs are good. Have had the alternator checked (was suggested because of sudden tachometer drop) but no problem found. There is fuel pressure and the injectors all click on signal. The ECU does not show any sensor problems. Switched the airflow meter with one from a running RR. Kind of out of ideas... Any suggestions on where to look further? Thanks, Onne I had a similar thing happening with increasing regularity, had heaps of suggestions from Forum members here and on other forums, all very expensive....finally traced it to the faulty temperature sensor located on top of the engine just in front of the injectors which was indicating that the engine was cold so the ECU was delivering more fuel than required...cost $30AUD...all fixed now . Hope this helps...Good luck. Quote Link to comment Share on other sites More sharing options...
ramon alban Posted March 7, 2010 Share Posted March 7, 2010 Been having stalling problems before when idling (with hot engine) where the tachometer would suddenly drop before the engine died. Have checked the ignition; sparks on all plugs are good.Helo Onne, Only have experience with earlier SD1 system, but two possibilities come to mind: # The ignition amplifier is dying, when hot and killing the ignition, only to recover its vitality when cold and temporarily give you back the missing sparks. # Ignition amplifiers have a finite lifetime typically in the range 60,000 - 100,000 miles Alternatively # Your tacho dying as engine stalls suggests an intermittent connection from Coil Negative directly to the Tacho and via a Trigger Resistor to (normally) pin 1 of the ECU. # Check all the White/Black wiring connections there-abouts for integrity, corrosion, breaks. # Hopefully this circuit should be similar to yours. Forgive me if these are false trails. Ramon www.vintagemodelairplane.com Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted March 8, 2010 Share Posted March 8, 2010 Is the car running Oxygen sensors/Cats ? Were the plugs fouled when it conked out ? Was the spark still present at the plugs when it conked ? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 8, 2010 Share Posted March 8, 2010 Check the ignition amp (on the side of the dizzy), as said they have a finite life & tend to get intermittent with heat before finally going. Also check the feed from the amp/coil -ve to the ECU, if this is dodgy the ECU doesn't know the engine is turning and hence doesn't inject any fuel. There's a hotwire EFI diagnostics guide in the technical archive, best thing is to work through it methodically (don't skip any steps because "it's probably not that") and report back any unexpected results. Quote Link to comment Share on other sites More sharing options...
4bakker Posted March 10, 2010 Author Share Posted March 10, 2010 Thanks for all the suggestions! I will be working on my LR tonight checking the ignition amp, coil -ve lead to ECU and work my way through the 3-1.9_Hotwire_System_Diagnostic_24_tests.pdf steps (includes temp sensor). Will post any findings tomorrow. Quote Link to comment Share on other sites More sharing options...
4bakker Posted March 11, 2010 Author Share Posted March 11, 2010 Thanks for all the suggestions! I will be working on my LR tonight checking the ignition amp, coil -ve lead to ECU and work my way through the 3-1.9_Hotwire_System_Diagnostic_24_tests.pdf steps (includes temp sensor). Will post any findings tomorrow. There is a good spark at the right timing (now well before on 12"). Not sure how to check the Ignition AMP? Getting a consistently good spark... There is correct fuel pressure on the fuel rail, no visual leaks. Smell patrol at the exhaust after starting so its getting fuel through the cylinders . Not sure how much though... smells like too much Checked the coil -ve Voltage on the back of the ECU connector: reads 10 Volts (so within 9.5 +/-1V). Not worked my way through all the diagnoses steps yet (up to step 8). Checked temp sensors both readings correct 14 and 15 degrees C. Need to finish the other steps of the diagnoses but above baffled me as I seem to get all ingredients: compression, spark & timing, fuel.... not picking up at all. Can the ECU/injectors flood the engine so quickly that it doesn't pick up even? Have not yet checked the signal on the injectors with a light. Could they be open all the time / too long pulse? I guess I have to pick up at step 8... Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted March 13, 2010 Share Posted March 13, 2010 Fouled plugs? Might be worth popping them out and cleaning them up. Quote Link to comment Share on other sites More sharing options...
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