MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: TheBALDpuma on October 25, 2024, 05:31:49 pm
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On two occasions now separated by a few days, I've gone to start my car and it's turned over loads before it's actually fired up. When it has fired up it runs fine but the EPC light is on. If I turn the engine off, and start again it's fired up fine and the light goes off.
Any ideas what's going on?
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On two occasions now separated by a few days, I've gone to start my car and it's turned over loads before it's actually fired up. When it has fired up it runs fine but the EPC light is on. If I turn the engine off, and start again it's fired up fine and the light goes off.
Any ideas what's going on?
Have you got any means of scanning the car? Wild guess would be a low pressure fuel pump issue, as said needs diag running on it
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I was thinking fuel pump too. Is that a big job?
No means of plugging it in I'm afraid, it will be a trip to the garage for diagnostics
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It's accessible from under the rear seat the tank doesn't need to be removed to swap the pump.
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Thanks - just watched a video and it looks a pretty easy job!
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On further investigation I don't think it's the fuel pump. Mainly because it runs completely fine once it starts
Here is a video of the non start. When you turn the ignition on, it will sometimes make this ticking noise. If it's making the ticking noise, the car won't start. Sometimes it doesn't tick, sometimes it does for a few seconds, sometimes it does it for a few minutes.
When it ticks the fan turns on even from a completely cold start.
When the ticking stop I get a whine. And the engine will start.
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From my experience, when you turn the ignition on and the fan turns on, it usually means some ECU issues. If you have a badly made map on the car or some ECU software error, the car refuses to start (it will crank), the epc and check engine light stay on and the radiator fan(s) turn on full blast.
The clicking you are hearing is the throttle body rapidly opening and closing, or just moving between 2 set positions.
Check wiring, check ecu I guess?
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From my experience, when you turn the ignition on and the fan turns on, it usually means some ECU issues. If you have a badly made map on the car or some ECU software error, the car refuses to start (it will crank), the epc and check engine light stay on and the radiator fan(s) turn on full blast.
The clicking you are hearing is the throttle body rapidly opening and closing, or just moving between 2 set positions.
Check wiring, check ecu I guess?
Yeah I think that's the go to.. I am a little embarrassed that I may have mashed the wiring with the windscreen wiper linkage that I replaced a few days before I started getting problems :sad1:
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Hey, at least you have a lead now. Replacing the windshield wipers on these cars is a pain but if you wanna see real pain, try doing it on an Audi A4 B7. You either remove the ecu and it's case or you have a friend bend it and pray to god it doesnt break since it's a 20 year old plastic. You need to wiggle that sh*t around for at least 30 minutes to take it out but funny enough, it slides back in without issues :signLOL:
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So I sent the ECU off to ECU Repair and they sent it back saying it was untestable so I decided to buy a salvaged part from eBay and have mine cloned and replace it.
Replacement ECU fitted today, and so far so good with no issues starting yet so I'm tentatively saying it's sorted!