Last chance to save my Mk3!

[ineson]

Starting to lose the love for my mk3 at the moment and at the end of this week it could be going (sold or broken) if I cant fix the faults. It our only car at the moment and me and the mrs are having to drive my dads cav sri around until we are sorted.

Its just been serviced and was running fine but has developed a fault of cutting out and not starting again. It started off by just not starting, I noticed it was onshorter runs around town etc that it wouldnt start but after a long run it was fine. Then it started cutting out and would not start again, only on a bump start.

Got a mate who runs a garage so took it in there for him to have a look at. He has put it on a vagcom but nothing has shown up. His inital thoght was the crank sensor so replaced that. The wiring had broken so thought it would be fine then, but no nothing changed. Since then it has had a new dizzy cap and sender, coil pack, and hall sender.
He has had a look at the ecu over the weekend and found that it has been tampered with by the previous owner so he is sending that away today to get tested etc.

I am close to spending more than I would like to on the car and am seriously thinking of breaking it this weekend if all else fails.

Any suggestions?

[kells]

id have done the usual relay swaps, ecu one and the other one, cant remember off hand

then id check the ignition switch

i had exactly the same issue, mine was the ignition switch

[ineson]

Yeah had all the relays checked and swapped, just phoned him to make sure he has tried the ignition switch, really am getting peed of with it now, just need my car back.

[kells]

Yeah had all the relays checked and swapped, just phoned him to make sure he has tried the ignition switch, really am getting peed of with it now, just need my car back.

i was the same matey, its only issue iv ever had, i worked out if i held the ignition wires it would run haha, so i tie wrapped them up and it got me around till i could get it sorted...  you just gotta try keep the faith

[ineson]

I will try mate but not good not having a car over the bank holiday and needing to get the mrs sorted with a new car but cant go anywhere to look for one.

Damn VW, lets hope its sorted this week or there will be a few gti parts for sale on the forum!

[slicksps]

Never give up!

I'm just throwing this in for ideas but it's very unlikely to be the case in yours.

I had a killswitch relay with my alarm which I needed to wire up to the coil, I'm sure it was wired up properly, but it cut out a couple of times at low speed. (scary stuff when the power steering cuts out with it)

Luckily I always keep a few tools in the car so disconnected it and crimped the wires back together, it's been running fine since. Looking through other cut-out problems, it could be all sorts of things, but think logically. The engine needs fuel, air, a spark and to be moving to get the cams and sparks working.

Rule out the last one and you're left with air, fuel and electricity.

Air is the easy one to check so unlikely.

My vote is on the electrical system as above. It sounds like a loose connection or damaged wire. Like my problem, it disconnected and reconnected on vibration so if you can, run at idle and shake it. (bouncing it probably won't be enough)

Does the stereo switch off as well?

[ineson]

Yeah it has done mate, has switched off on its own and then come back on without warning. Only just installed a new one a few months back aswell. I think its electrical aswell and thats what they are looking at now. Fingers crossed.

[slicksps]

That's good, it rules out immobilizer, and billions of other things. (assuming it's caused by a single fault)

Ignition lead is probably fine then, but the problem is going to be somewhere between the battery and the ignition switch. As this wire is always live, it should be relatively easy to wire up a voltmeter and twiddle the wires en route.

I believe (but I could be wrong) that the only connections are the battery terminals (+ to igntion switch and - to body) in the fusebox and the ignition wiring harness, so assuming the wires themselves are ok, there shouldn't be too many places to check.

My first bet is the Earth and battery terminals as they're the easiest to reach, then check ignition harness and fusebox together as you/they would need to remove some of the same panels. If you've fiddled with anything in that system though, always check there first.

The electrical wiring is much simpler than it looks and all follows the basic circuit system, the only difference is that the entire chassis is wired to the negative terminal so I found that many things only seemed to have a positive connection.

[Mikester]

I had the same problem. Was the ignition switch too mate.

Very very comment fault on the mk3. And it seemed like it was other things. When in fact it was just the ignition. I would sit there tryin to start it. Get pissed off, push it bloody hard, and it would start. eventually it got worse and worse till it wouldnt work at all. Had to bump it to the auto electrician.

Check it mate Aint expensive either

[Guy]

dude... just checking, although you probably have... have you cleaned the throttle body?