Ghost issues

[Michaelc5086]

Hi guys having some issues with the gti. 

Car wouldn't start this morning and the dials were bouncing up and down! Managed to start it and kept it going by reving the tits off it.

But as usual the car has fixed itself and gone back to normal. For now! Has anybody got any ideas?

[RetroPug]

Check and clean up all of your earths. Even if that isn't the issue it's worth doing anyway to avoid similar issues in the future.

[Michaelc5086]

Aye I'll give it a go. I'd forgotten how fun French electrics were. No issues like this with the old Saab

[cully]

check all the following to start with as bouncing clocks tend to be low voltage
Battery itself,battery leads and both + and - terminals
chassis earths under battery and gearbox
also check the Positive on the alternator with the engine loom + take off

[Michaelc5086]

Cheers again. Unfortunately it's pissing it down now. But it does seem to be working for now. I'll have a look in the week and fingers crossed for work tomorrow.

I don't want to be pedalling the rest of the week

[Michaelc5086]

Still no luck with this car. Taken the earth's off and cleaned the points. I'm charging the battery again and also tried the car jumping it off another. Still has bouncing gauges and isn't starting.

Can anybody else suggest anything else?

[7057sam]

Mine once cracked really slow but still started.
But hasn't done it since even started it yesterday at -2 and was ok.

It always does the dial swipe once aswell

[Michaelc5086]

No such luck for mine. I've given up today. Charging battery tonight and tomorrow is a new day.

The gauges don't just stop through. They are continuously bouncing.

[RetroPug]

Have you borrowed another battery just to try?

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When it doesn't start what is actually happening? Symptoms of low voltage? Starter motor turning or not?

[Michaelc5086]

Have you borrowed another battery just to try?

---

When it doesn't start what is actually happening? Syhi mate.

Symptoms of low voltage? Starter motor turning or not?

Hi I tired to use jumper cables of somebody else's and it wouldn't work. The starter motor turns and it tries to fire but doesn't. If it does start it cuts out pretty much straight away

[Michaelc5086]

Hi back to my gti worries sorry if I'm bugging everyone . I have charged the battery and the car is still trying to fire. But I have a clicking noise from the box behind the ecu and the fuel rail. It's getting to quite a bit of pressure because some petrol has escaped.

Does anybody have any ideas? Iv tried uploading a video but it won't let me

[RetroPug]

Those are screenshots. Is the clicking noise from the box in the top one? That's the fuel/ignition relay, if that's playing up it could cause issues.

I'm sure someone has a known good one they could sell you.

[Michaelc5086]

Those are screenshots. Is the clicking noise from the box in the top one? That's the fuel/ignition relay, if that's playing up it could cause issues.

I'm sure someone has a known good one they could sell you.

Thanks again. 

I have replaced the relay with another and it is still clicking. If these click does it definitely mean they are broken or could another issue cause it to click?

[RetroPug]

I've no idea to be honest!

[Toms306]

Relays should click... Its when they don't you have a problem lol.

When you say some petrol has escaped, is it leaking from the pressure regulator (round silver thing in pic)?

[Michaelc5086]

I realise that :-) it was continuously clicking on and off. It seems to have stopped now and only clicks once with the ignition on to prime the fuel pump.

[Toms306]

Still sounds like a poor earth then tbh.

[Michaelc5086]

In all fairness I think it might have been. It stopped clicking once I took of the earth's and RE attached for the second time.
Last night I went through slot with a multimeter. It turns out my crank sensor isn't giving a resistance reading I.e isn't making a circuit. So I think that's my problem

[Toms306]

Ah I see, yeah they won't start without a crank reading. Hopefully a new one fixes it.

[adam b]

You cleaned the gearbox top earth point yeah?

Also could be connection through the bulkhead getting damp, earth points under the dash or a blown fuse

[Michaelc5086]

You cleaned the gearbox top earth point yeah?

Also could be connection through the bulkhead getting damp, earth points under the dash or a blown fuse

Hi Adam.

Yeah I cleaned the earthpoint on the gear box and checked all my fuses. I haven't checked the internal earth's though. I shall do it this weekend.
I have however checked the voltage to the fuel pump, all the coil packs and the crank sensor and all is fine. The only thing (so far) that hasn't given the correct readings is the resistance of the crank sensor. Also I have no spark. So I'm hoping replacing that will do it.

[cully]

Checking resistance - (pic)
Technical Data
Terminals Resistance
1 & 2 300-400 Ω

Ensure ignition switched OFF.
Disconnect CKP sensor multi-plug.
Check resistance between CKP sensor terminals (pic)


Checking signal - (pic)
Technical Data
Terminals Voltage
1 & 2 1-4 V ac (fluctuating)

NOTE: Disconnect injector multi-plugs before cranking tests, to avoid damage to catalytic converter(s).
Ensure ignition switched OFF.
Disconnect CKP sensor multi-plug.
Adjust voltmeter to measure alternating current.
Briefly crank engine.
Check voltage between CKP sensor terminals (pic)

   

[Michaelc5086]

Checking resistance - (pic)
Technical Data
Terminals Resistance
1 & 2 300-400 Ω

Ensure ignition switched OFF.
Disconnect CKP sensor multi-plug.
Check resistance between CKP sensor terminals (pic)

Cheers cully that's what I've done and the sensor isn't giving a resistance reading (no circuit).

Checking signal - (pic)
Technical Data
Terminals Voltage
1 & 2 1-4 V ac (fluctuating)

NOTE: Disconnect injector multi-plugs before cranking tests, to avoid damage to catalytic converter(s).
Ensure ignition switched OFF.
Disconnect CKP sensor multi-plug.
Adjust voltmeter to measure alternating current.
Briefly crank engine.
Check voltage between CKP sensor terminals (pic)

[cully]

   

[Michaelc5086]

Thanks again cully I assume mine is dead then :-)

[cully]

looks that way

[Michaelc5086]

SHE LIVES :-) it was the crank sensor.

But I dropped the stupid f#$#ing bolt. I can't see it in the dark so cycle patrol again tomorrow

[Toms306]

I doubt its gonna jump out without the bolt... But I hope it hasn't dropped into the bellhousing lol.

[Michaelc5086]

Ha it better not have done. The job was to fiddly for my stupid hands.

Meant to say cheers for all your help guys