starting problems

[cartandpeg]

Hi,

car is VW Golf 2003 Mk4 2.0 lt sport.

Going back 4 days ago, the car refused to start, the engine cranked over fine.

I am having a problem with one of the door locks not locking or opening, so as last resort I messed about with the door lock knob and the car started.

So at that time I assumed it was something to do with some form of security issue and the lock was causing the starting problem.

Since then the car has started and driven fine.

Drove home from work, 5min trip, went to start car approx 10 mins later, same issue would not start.

So messed about with door locks assuming it was the issue, all to no avail.

Locked car went away for about 30 mins came back and was going to crank engine over to see if the tacho would show some reading and then do spark test.

Car started up straight away, so was unable to carry out further tests.

It still starts ok now.

Any clues please.

I am thinking maybe crank angle sensor, but, thought I would ask here rather than spend dollars on various sensors.

Many thanks.

[Alex Mckenzie]

Do you hear the fuel pump charge when you open the door ?

If not, maybe pump relay (I think it’s labeled 409)

If pulled them apart, cleaned the contact (light sand with 2000 grit sand paper) as A’s short term fix.

But before you jump to that, if you done’t hear the pump prime when you open the door it may also be the door sensor
Easy check, do the interior light come on when you open the door.

May also be the fuel pump,

Check the relays under the dash #409
Hope that’s all it is, and where I’d look first.

Good luck


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[Alex Mckenzie]

Oops sorry I missed the part of your post where you advise it started

May still down the track



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[cartandpeg]

Thanks Alex,

I will keep would you have said in mind,if it does it again.

Cheers.


Just went to VW dealership, they think it may be the ECU at like a price of $1900.00, I think I will trouble shoot for the time being.

[jmcc]

Sounds similar to my crank angle problem on a 1.8t, but mine would stop running occasionally, and seemed to be affected by heat, so after running a while and not wanting to start, leaving it for a while it would start.

On the fuel pump, my mechanic who is a 60+ year old petrol head told me once the best way to test is if its not running, give the tank a wack near the fuel pump, if its got a dead spot it move it just enough to get spinning again.

[cartandpeg]

Thanks jmcc, I might just change this crank angle sensor over and clean contacts on fuel pump relay.

After pricing parts from VW Dealership, I shall be going for after market ones.

Cheers.

[littlegldgti]

I had warm stall/start issues with a V5 Bora for a while. Car started perfectly all of the time when cold. Struggled a bit when warm and would occasionally stall the engine when it was warm and refuse to start up for about 30mins. That was a crank angle sensor.

The fact that the car is having issues on a cold start makes me think it may not be a crank sensor problem, but I'm happy to proven wrong.
The lock on the door may be a coincidence - Whats the issue you're having with it?

*Happy days in Mk4 land*

[cartandpeg]

littlegldgti, no issue at present it is running fine. On 16/02 it would not start, hence what I thought was the door lock (security) causing the problem..The car engine was cold, after awhile it started

Drove home 3hr trip and the car started with no problems, I switched it off let it sit for 10mins and went to see if it would start, no problems with starting then.

On 20/02 same problem.

Messed about with door locks, still no start, the engine was warm, not up to operating temp.

Had a few things to do, came back and it started no problems, been running fine since.

Though more than likely the problem will arise again.

Today 22/02 I took the fuel pump relay out and apart, contacts looked fine, but just ran some 2000 grit wet/dry over them.

I removed crank angle sensor, though that really told me nothing, I needed the part number from it, so that was main reason for removing that.

I have not had the opportunity to check if it might be fuel or spark as the car has not refused to start.

[cartandpeg]

Ok I have been unable to go any further with this problem due to knee replacement, how ever I have managed to teach the good lady of the house on some basic mechanics.

Removed induction pipe sprayed in some aero start ( engine start) and no worries the engine wanted fire up with that going into it.

Would I assume a fuel problem, seeing there is spark there to ignite engine start.

Thank you.

[Bozfromoz]

I have the same problem, but I bought a car that didn’t start. It’s my little project. I have good spark so it must be a fuel problem as I used the starting fluid spray and it worked with first crank and it drives perfectly. I will keep people update with my findings !

[jmcc]

These cars have "for life" fuel filters, but alot of people on forums have pulled them off after 100k km and you can barely blow through em, maybe check there

[Bozfromoz]

Hey guys just following up. I fixed my starting problems and now she drives like a dream and the petrol pump primes ! I can’t believe it was all because of the 101 fuel pump relay but it was !

[cartandpeg]

Thanks for replies.

I am sure it is the fuel pump, I have voltage to the pump with ignition in on position and voltage when cranking.

Ohm meter is showing 5.8 resistance on number 1 and 4 pins on pump.

[Bozfromoz]

Thanks for replies.

I am sure it is the fuel pump, I have voltage to the pump with ignition in on position and voltage when cranking.

Ohm meter is showing 5.8 resistance on number 1 and 4 pins on pump.

When you put the key into the ignition does the pump prime (hear a noise from the back) if not try taking out the fuel pump relay and bridge the connection and see if it primes. It’s more likely to be a relay than the actual pump.