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I have an intermittent starting problem with my RS2. Engine turns but will not fire. I think that it must be an issue with fuel supply. Possibly the fuel pump relay. I have checked on the FAQ page and note that the fuel pump is not energised when ignition key is in position 1 - I thought that the pump was supposed to prime in this position. I have also read that a faulty cam shaft sensor will not prevent the fuel pump energising. Both of these seem slightly counter-intuitive. Any suggestions and/or confirmation of the above and where to start looking for the problem. Car very regularly serviced and recently had new spark plugs. Battery fine. Car runs very well when it does start.
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Cheers
Don
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Everything in perfect working order
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I could be wrong but i though the fuel pump was only energised when the hall sender is sensing a minimum amount of rpm? (Safety measure in case of accidents etc)
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How about Dead Petrol .. i had that problem .. todays petrol is good for only about 6 weeks.
I buy some Briggs & Stratton stuff off ebay for keeping lawn mower fuel alive over the winter & it works very pleased to say. BUT this treatment has to be used into good fuel not fuel already dead.
Biggest problem i had is how to get rid of all this dead petrol after draining it out of the RS2.Comment
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Fuel pump is energised/primed in position 2, i.e. run. Should should be able to hear this with the door open in a quiet area.
It's quite normal for injectors to only be fired or even powered until spark signal is sensed by ECU.Comment
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Get a friend/kid/wife to crank the car , get access to ECU - once the engine starts to crank, in a second or two you should hear a click ! of a relay in the ECU - only if camsahft and crankshaft position sensors have come to a consensus
. That should help you isolate sensor problems ( apart from a temperature sensor )- then you only need 1. Spark ( easy to check ) , 2. Fuel ( not so easy to check - but you can always disconnect the fuel line from fuel rail and use a plastic can or bottle to make sure fuel is flowing )
No MAF, ISV, etc are needed for a car to start
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From my AAN experience (if ADU is similar), fuel pump is engaged if ECU senses more than 13 rpm from the crank position sensor. So if you're missing fuel, that would be where I start. Spark is engaged from cam position sensor.
I once had a bad fuel pressure regulator, and also had intermittent starting issues, when I had to crank the car for a long period and it would bubble, but when started it ran without a hiccup. Bad petrol can also be the cause, I experienced a no start when I tried to start a freshly rebuilt car after 9 months of it staying in the garage.
You can always start going over the underlying stuff, like let the fuel pressure line banjo loose & see if fuel is coming. If the pump is engaged it should come fairly quick. Then just start from there. Injectors get power when ignition is turned on, so you will see +12v on one of the injector wires.
Again this is all on AAN, can't say if ADU is the same.Comment
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Thanks guys. Fairly certain it is not bad fuel. Working on it by a process of eliminationCheers
Don
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Everything in perfect working order
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Originally posted by Don View Post
One issue to add is if you are using the more modern coils ( TFSI ones ) , they seem to need a good battery otherwise do not provide a good spark on startup. Also I recently had a starting issue from a bad ign coil harness ( done by myself ) , a wire was loose from a pin ,and had to crank for 5+ seconds for the engine to start
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Don, any updates?Comment
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