Engine Won't Start

[scbond 15 1 Cars]

Last night, during heavy rain, I tried to start my car (1.9 8v standard, phase 1.5) but it wouldn't turn over. The key turns, the normal dash lights come on and the fuel pump primes. There is sometimes a few clicks from around the steering column but they don't continue and rarely happen.

 

The voltage on the battery is about 12.67v. I haven't touched the starter or the feed wire and the brown plug was removed several months ago.

 

Only thing I've done recently is dissasseble the rear earth and clean it. After doing that the engine started before I could even turn the key fully.

 

Yesterday it did crank slowly once so I stopped the engine and checked the oil (knowing there's a leak) and other than a small bit of mayo I didn't see anything wrong so topped it up and it started fine.

 

Bit stumped as the battery seems perfectly healthy and I haven't had any issues with it. It's only struggled the past day and now it won't even crank.

 

Any suggestions? Tried aearching but could only find suggestions about a knackered or seized starter or a dying battery.

[scbond 15 1 Cars]

Anyone?

[jackherer 543]

As a test unplug the small wire from the starter and hold the bare end of a spare bit of wire on the starter terminal then touch the other end of the wire on the battery positive terminal. Make sure it is in neutral first or you risk running yourself over...

[borufus 17 4 Cars]

Check for a starter signal at the starter motor, ( small wire) when the key is in crank position!

[jackherer 543]

That is only a worthwhile test if the wire is connected to the starter at the time. If there is no load on it you may well see the full battery voltage but as soon as a load is applied (i.e. when it is plugged back on to the starter) that voltage drops right down due to resistance caused by corrosion.

[scbond 15 1 Cars]

Haven't had chance to check that yet Jack as time has been very limited.

 

I have tried another battery and there was no change. Could it possibly be the rear earth block connection? This is the only thing that would affect the starting of the car to have been touched as I described in the first post. One instantaneous start, some normal and then a couple of struggles and ultimately nothing. All I did was take the block out and dismantle it to clean it with solvent. Noticed that not all of it was shiny but not sure how to clean it up good as new and only thing I can think will solve it fully is to put a ring terminal in instead.

[jackherer 543]

Do you mean the earth in the behind the rear light cluster? That wont stop the engine turning over, it could stop the fuel pump getting power but the starter would still work. The only earth that can stop the starter from turning is the main one from the battery to the gearbox.

[scbond 15 1 Cars]

That's odd then...I've had the earth cable behind the rear light cluster unplugged before and the car wouldn't start at all, same as now.

 

Biggest issue I have right now is that I can't access the starter motor...the loom running under the manifold is in the way and I don't want to risk disturbing the signal wire for the starter by pulling it all aside.

[jackherer 543]

Does it have an immobiliser? That could be earthed at the rear I suppose, would be an odd way of doing it though.

 

It's worth persevering with hotwiring the starter, you should be able to access it without too much difficulty.

[scbond 15 1 Cars]

No immobiliser but like nearly all of them, it has had an alarm in it at some point. A previous owner had removed that.

 

Will try and have a look at the starter tomorrow and will check the gearbox earth strap. Not sure if I have the wire to bridge the starter but will try and work something after looking at it.

[jackherer 543]

You can use a really short bit of wire and just bridge between the main power cable on the starter and the blade for the solenoid but you need to be very careful to not let it short to the inlet manifold or anything else metal.

[scbond 15 1 Cars]

Short isn't as mush the problem as much as thickness is. I know it'd only be a brief bridge but still!

[jackherer 543]

It's just the solenoid feed so it doesn't need to be very substantial.

[scbond 15 1 Cars]

Ok, managed to get to the feed wire and pull it off. Has been messed with in the past as there a insulated female spade on the end and a crimp connector a few inches down. Cleaned up the wire but can't see signs of that playing up...as dodgy as it looks. Will hook the battery up and try your test.

 

Out of interest, what is the amperage of the solenoid feed? I'll try and get the wire replaced asap.

[jackherer 543]

The extra crimp connector doesn't sound good! Even a little bit of resistance leads to enough voltage drop to stop the solenoid triggering.

 

I don't know how many amps it is, probably a max of 8-10 ish. I think that is only a very brief peak though, once the solenoid is triggered it uses a lot less current to hold it there.

[scbond 15 1 Cars]

Ok, so basically there's a crimp near the spade as I said before...this is in addition to one I put in as a temporary measure at the brown plug. It has always appeared to work fine previously though.

 

Just did the test and nothing happens other than some sparking at the positive battery terminal. No cranking. Not sure how good a connection I got though as I had to squeeze my right arm in to hold the wire on without touching the copper and then touch the terminal end with my left arm.

 

Did notice that, with the key to ignition, when I connected the battery I could hear a whining from the fuel filter. Perfectly normal?

[jackherer 543]

If it was sparking at the battery terminal there was definitely a complete circuit! As long as the other end of the wire was touching the terminal and not shorting to earth on the starter body etc. that rules out the solenoid feed. BTW it is only 12v so it is fine to be touching the terminal.

 

It's worth checking the gearbox earth, battery clamps and the high current cable between the battery and starter but it sounds like a problem with the starter motor itself.

 

The fuel pump shouldn't run continuously with the ignition on but the engine not turning over, if it does either the tachymetric relay is sticking or it has been bypassed, i.e. the pump has been hotwired with an ignition switched feed.

[scbond 15 1 Cars]

Awww...more stuff to check then! Will try and find the Tachy relay but that's for another time I guess. Couldn't actually hear the pump itself from inside the car, just a slight noise from around the filter.

 

Thing that confuses me with the starter motor is that it worked perfectly a few days before it wouldn't start. Like, it literally started the car before I could fully turn the key. Is it normal for a motor to just suddenly die like this? I mean, I know it can happen on a tired one if the battery goes but it turns out the battery was fine.

 

I did find the gearbox earth but didn't remove it, just sprayed it with contact cleaner and it looks a little better now. It was rigid and doesn't look damaged. Will try removing it tomorrow and give it a full clean. The battery clamps seem fine...the positive looks a bit suspect if I had to pick at something but the cables are still secured.

 

As a precursor, how many bolts is the inlet manifold? Any unusual sizes and any that are hard to access? If it is the starter then it'll need to be manifold out as the car is half parked on a kerb and I also have no jack, let alone a suitable one, so radiator out is out of the question, as is getting under the car.

[jackherer 543]

The tachy relay is under the dash on the drivers side by the ECU in a p1.5.

 

Starters can just die but it is normally wiring problems with 205 GTIs. The gearbox earth should have a toothed washer to help it make a good contact so it's worth unbolting it to check it's there. There should also be one on the high current cable where it bolts to the starter.

 

I know it's hard to believe but you can remove the starter (even fat body original ones) without removing either the radiator or the inlet manifold, I've done it many times.

[scbond 15 1 Cars]

Definitely a toothed washer there.

 

Is there any other way to be sure it's the starter motor?

 

Also, would prefer to have the inlet off just to make life easier.

[jackherer 543]

Confirming the electrical connections are good is the only way to test it in situ really.

 

Once it is off the car you can connect it to a battery with jump leads then touch a wire to the solenoid terminal and it should push the pinion out and spin fairly fast.

[scbond 15 1 Cars]

Ok, and shouldn't it have done that when I bridged the solenoid to the battery before? I had the key to ignition or does it need someone to turn it to crank while I bridge it?

[jackherer 543]

Yes, it should have done that when you bridged it, there is no need to turn the key, that is what you are bypassing.

 

That proves that the solenoid wiring is not faulty (or if it is you have more than one fault) but testing it on the bench with jump leads bypasses any wiring faults on the car (the main power feed and earth) leaving only a faulty starter as a possibility.

[scbond 15 1 Cars]

Ok, I'll try one other thing and will check the voltage of the solenoid feed with someone turning the key. Hoping to find any fault other than the starter motor

[jackherer 543]

Make sure you check it with it plugged in to the starter, with no load on it you might still see 12v even if there is some high resistance somewhere.