Yes I have a fuel pressure gauge, seems normal. One of the codes I got was for the second lambda signal being too high, so you think the coolant sensor could be to blame?
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i would not have thought that the coolant sensor would cause the car to not start.... it just causes it to over-fuel (as the ECU always thinks the engine is cold) and this does not get burned correctly so the exhaust gasses have some un-burnt fuel in them - why i was getting the error.
But in saying that the sensor is cheap (£10/20 i think) and if it's been on the car for a while it could be on it's way out, think mine lasted 4 years (two of them with a re-map & track time).
ta, Dave
But in saying that the sensor is cheap (£10/20 i think) and if it's been on the car for a while it could be on it's way out, think mine lasted 4 years (two of them with a re-map & track time).
ta, Dave
It's a green one but is about 3 or 4 years old now. I'll change it anyway as it's cheap, one less thing off the list!
Jim has checked the ECU for any signs of water ingress but found nothing, the connectors are fine too. Almost at a loss as to what's wrong now.
Jim has checked the ECU for any signs of water ingress but found nothing, the connectors are fine too. Almost at a loss as to what's wrong now.
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Well it seems that after trying many different things my car is still cutting out and not starting, so it may be a faulty ECU! Anyone know how much a new ECU is - I'm guessing alot! 
Anyone got a spare Leon Cupra AUQ ECU lying around?
Anyone got a spare Leon Cupra AUQ ECU lying around?
Nope, car is still randomly cutting out and not starting, plus not making boost, with Apexi set to 1.2 BAR it only makes 0.7 BAR.
Just had an update from Jim, he has had the electrics checked over by a specialist and apparently the battery cable from the boot to the engine bay isn't heavy enough for more than 2 cranks. I used 4awg cable but it seems it has to be 0awg cable. The car is also over-fuelling on startup.
Finally we're getting somewhere. New battery cable and a map adjustment should hopefully fix it.
Finally we're getting somewhere. New battery cable and a map adjustment should hopefully fix it.
Long time - 9 months to a year! I think the cable is breaking down inside and isn't rated for the ampage of the alternator, I think I need 25mm 170 amp cable.
The electrical guy has probably told Jim what cable to use.
The electrical guy has probably told Jim what cable to use.
It would melt the cover before breaking down Rob. Is the cable ever hot to touch? The actual core on my battery cable is only about 10mm and that's been there for a few years now.
No idea, just relaying what I'm being told. Might just stick the battery back in the engine for less hassle. The water injection tank and pump will be going in the boot anyway.
Do you knowif they have tried the battery in the engine bay with a normal cable to see if it makes a difference. I think they're clutching a straws personally.
Some of that does make sense....
If the cable is not heavy enough then what will happen is that when it's under load (starting or all the lights/ICE running, but no engine running) you will get a voltage drop across the cable, so if it should be say 13v you will get that at the battery but perhaps only 12v at the engine - the other 1v is lost in the cable (numbers for example only!!!!).
And what happens to the cable when it's under-rated is that the voltage drop generates heat in the cable - and that heat incleases the voltage drop - ever-worsening circle (follows for the two-cranks comment as well.)
So that bit could hold true.
All comes down to the sparky, is he guessing at this or has he actually measured it, and as Baz said - have they tried just sticking it back (perhaps need the cables for this??)
If the cable is not heavy enough then what will happen is that when it's under load (starting or all the lights/ICE running, but no engine running) you will get a voltage drop across the cable, so if it should be say 13v you will get that at the battery but perhaps only 12v at the engine - the other 1v is lost in the cable (numbers for example only!!!!).
And what happens to the cable when it's under-rated is that the voltage drop generates heat in the cable - and that heat incleases the voltage drop - ever-worsening circle (follows for the two-cranks comment as well.)
So that bit could hold true.
All comes down to the sparky, is he guessing at this or has he actually measured it, and as Baz said - have they tried just sticking it back (perhaps need the cables for this??)
Well this has come from an electrical specialist who has taken a look at my car, not from Jim, so this guy must know what he's doing. I believe he measured it when trying to start the car and there wasn't enough juice after 2 goes.
If it's just some new battery cable and a map adjustment then hopefully it's an easy and cheap fix.
If it's just some new battery cable and a map adjustment then hopefully it's an easy and cheap fix.
Undersized cables can be an issue but should have shown sooner. My money is on the battery. Do you know if they tried a new battery to eliminate it.
Can't see it being the battery but I can understand if the cable can't carry the juice required to start the car. Might just put it back in the engine bay, but I'd need a new battery tray and cables from SEAT to do that. I'd also need a different air filter too!
Got my car back this morning, still not fixed yet though. I'll have to replace the battery cable to the boot and it appears it's not making boost due to a knackered actuator or the Apexi solenoid.
At least now I have it back I can get stuck into it and try and fix it.
At least now I have it back I can get stuck into it and try and fix it.
Yes thanks Bill, will take my time and go over all the points raised by the elec. guy and address them, need to find out why it's not making boost too. Star tested and found no boost leaks, Jim thinks the actuator may be goosed. I've asked Forge if they can supply me with one of theirs, if I send it to them they'll do me one.
OK the non-starting and cutting out issue seems to be fixed, since replacing all the battery cables with heavier duty stuff and replacing the battery with a larger one - seems to be all good now, starts great from cold or hot, first time.
Still no boost though, I disconnected the Apexi solenoid and fitted a manual boost controller - still nothing, won't go over 0.5 BAR.
Any ideas???
Still no boost though, I disconnected the Apexi solenoid and fitted a manual boost controller - still nothing, won't go over 0.5 BAR.
Any ideas???
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