gav- Posted May 30, 2020 Share Posted May 30, 2020 Hello, I am sorry to have to come back and ask another question but, after resolving my previous issue with a backfire(lead to the coil was wrong from edis) the engine ran well and I decided due to lack of time to disconnect the ecu and put it into safe storage for the past 5 months! so thinking this will be a good time to start work on it again, I plugged it back in and its failed to start. I don’t seem to be getting any fuel through to the injectors, crank is at 130-150rpm and a very strong spark, but removing two plugs they are very dry, and spraying a bit of cold start into the inlet the engine fires and then dies. fuel pump primes and return is flowing back to tank (checked ok) nothing has changed with the wiring for the past 5 months and I really can’t work out where to start! Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted May 31, 2020 Share Posted May 31, 2020 Is this a standard MS1 + EDIS setup? Is the fuel pump running / LED's flashing on the ECU when the engine turns - or to put it another way, is the ECU getting an RPM signal? Quote Link to comment Share on other sites More sharing options...
gav- Posted May 31, 2020 Author Share Posted May 31, 2020 Yes standard ms1 and edis. fuel pumps runs all the time, tunerstudio shows a 130-150Rpm of engine when cranking I have got 12 v feed to the injectors which drops to about 10v during cranking, (measured between injector feed and earth point on engine) if I connect a voltmeter to an injector connector I don’t see Any volts at all, or if I connect a voltmeter to the two wires going to all the injectors. The ecu doesn’t appear to be switching the injectors? I am wondering if I should connect the earths from the mega squirt directly to the battery? They are currently going to a shared point on the engine block. tunerstudio is showing no resets in the real-time display. Quote Link to comment Share on other sites More sharing options...
gav- Posted May 31, 2020 Author Share Posted May 31, 2020 Further fault finding tonight, is reset noticeable by tunerstudio loosing the connection during the crank and the SECL counter restarting? i am wondering if it’s the earths from the ecu yo the engine block?? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 1, 2020 Share Posted June 1, 2020 If you wire a light bulb to a pair of injector wires (or use a NOID light), does it flash? Resets are indeed indicated by the SECL counter restarting, if you're earthed to the engine block then during cranking your starter is raising the voltage of the engine block, especially if there's a bad earth from block to battery. Quote Link to comment Share on other sites More sharing options...
gav- Posted June 1, 2020 Author Share Posted June 1, 2020 By disconnecting the plug at the ecu, I have checked that there is voltage when the ignition is on through the injector circuit to the ecu. And I have rerouted the 3 earths to the engine block. I have one main cable from the battery to the engine block and all grounds connect to thIs same point On the engine block. When I switch the ignition on, the fuel pump primes, and i see all the gauges on tunerstudio. When I turn the key to crank, I loose the connection to tunerstudio (engine continues to crank) and secl restarts, and all the gauges appear with a crank rpm of 130 to 150. There is voltage to the injectors but the ecu is not switching them? The only thing I can think is that the reset (if it is a reset) stops the ecu from switching the ignitors? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 2, 2020 Share Posted June 2, 2020 11 hours ago, gav- said: The only thing I can think is that the reset (if it is a reset) stops the ecu from switching the ignitors? A reset usually means the ECU voltage dropped enough to cause it to stop briefly, so yes it wouldn't be doing much while it's "off". Without knowing your wiring scheme, is it possible you've got a weak battery or a weak 12v supply / bad connection that's causing the 12v side to drop under the load of firing coils & injectors? The ECU itself needs a fraction of an amp from the 12v supply so I'd doubt it would be creating a problem on its own. Quote Link to comment Share on other sites More sharing options...
gav- Posted June 3, 2020 Author Share Posted June 3, 2020 Hello, I have attached a couple of videos, I think the reset issue was due to the battery being slightly flat, its still not firing the injectors during the crank. the videos show the ecu red spark light coming on but nothing else. by the way the lambda and pwm are disconnected, hence the dials reading odd! Is there anyway of testing the injectors, or is there a setting i have missed in tunerstudio that could stop the injectors from operating? VideoCompressor_20200603123423767.mp4 VideoCompressor_20200603123407783.mp4 Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 3, 2020 Share Posted June 3, 2020 What's your TPS reading (throttle position sensor)? If that's over a certain threshold during cranking the ECU will enter "flood clear" mode and shut off the injectors. Quote Link to comment Share on other sites More sharing options...
gav- Posted June 3, 2020 Author Share Posted June 3, 2020 I did think that but with the throttle closed it 31 and foot to the floor it’s 254 during the calibration. Unless this can change during crank??? flood reset is at 200, Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 4, 2020 Share Posted June 4, 2020 17 hours ago, gav- said: I did think that but with the throttle closed it 31 and foot to the floor it’s 254 during the calibration. Unless this can change during crank??? Anything can change during crank if there's a fault, what does a datalog of cranking look like? Quote Link to comment Share on other sites More sharing options...
gav- Posted June 7, 2020 Author Share Posted June 7, 2020 hello, i cant determine if the injectors are openng during the priming pulse or during a crank. I have fitted a spare injector to one of the injector cables but cant hear or feel its opening. All of the plugs remain dry. I am wondering if my multimeter is quick enough to see the voltage pulse of the injector opening or not? I have attached a couple of datalogs, it looks like there is some fuel getting into the cylinders as the RPM does increase and it sounds like it fires and then dies. I am now wondering if its a fuel issue!! goign to try a new fuel filter, nothing seen in the old one though. or am i going down the wrong route? 2020-06-07_18.43.22.mlg 2020-06-07_18.45.19.mlg Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 8, 2020 Share Posted June 8, 2020 Unlikely your multimeter would see the pulses, they're <10ms and 1% duty cycle, with all the electrical noise from the starter it'd be quite hard to make out. Your datalog doesn't look wrong, you said in your 1st post some cylinders appear not to be getting fuel, I've had injectors or fuel pumps seize up in storage and known fuel pressure regulators to stick, sometimes a sharp tap can bring them back. If you can test the fuel pressure on the fuel rail that's a worthwhile one, a tyre pressure gauge on the schrader valve is close enough Quote Link to comment Share on other sites More sharing options...
gav- Posted June 11, 2020 Author Share Posted June 11, 2020 (edited) Hello, thanks for your replies it’s appreciated. I brought a noid light and I the light doesn’t light up when the pump primes or on crank. I know that the cables are ok to the injectors as if I disconnect the db37 and connect the injector circuit manually I can hear them click! I don’t know how it’s happened but I think there is something wrong with the ecu! Edited June 11, 2020 by gav- Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 11, 2020 Share Posted June 11, 2020 If you can, undo the top 4 screws on the ECU, lift the lid and snap a few photos and post them up. Quote Link to comment Share on other sites More sharing options...
gav- Posted June 12, 2020 Author Share Posted June 12, 2020 Photos of the pcb Quote Link to comment Share on other sites More sharing options...
gav- Posted June 22, 2020 Author Share Posted June 22, 2020 Hello, just to close this thread down, the problem turned out to be the ecu and a protection diode had blown! Fingers crossed it will fix things and I’ll have a working engine again! Thanks for everyone’s help Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 22, 2020 Share Posted June 22, 2020 Glad you got it fixed! Quote Link to comment Share on other sites More sharing options...
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