Starting Issues

[Ben Allen 8]

Right, I'm having some issues with my 1.9 GTi. It's now only a week until I'm supposed to be taking the thing to the Nurburgring and it still isn't working!

 

Basically it's not starting. The story goes that the other day it stopped getting fuel. I decided to hardwire the fuelpump to the tachymetric relay to get it running, so did that, rigged up a switch and Bob's your Uncle - it started and ran.

 

So, I left the car on the drive for another day while I went to Cadwell Park, and went to get in it and go out today, and it won't start again. Great. The fuel pump is working fine off my switch sending fuel to the fuelrail. I've checked the spark on all 4 cylinders with a spare spark plug and it's sparking on all of them.

 

Any ideas? I know the hardwiring of the pump isn't ideal by the way.

 

Someone mentioned it could be flooding the engine due to too much fuel coming through from the pump being hardwired.

 

Any help would be appreciated as I'm about to go mental with the thing and set fire to it.

 

Cheers

[pug309twin40s 1]

if the engine was flooding then you would smell it. take a plug out and see if its wet or very black.

 

 

have you tried another tachemetric relay on the car?

 

hard wiring the fuel pump shouldnt cause problems

[Alastairh 47]

Replacement taccy relays and the ecu temp sensor have both been swapped.

 

Likely the fuel regulator would cause these problems?

[James_R 3]

If it's getting fuel and sparking, then next is compression.

 

If it's over fuelling, then AFM, or coolant temp sensors, maybe the hall effect sensor in the dizzy.

 

HAve you got RAC home start??

[TEKNOPUG 3]

Try changing the ECU and tachy relay.

[Rob_the_Sparky 9]

Probably ignition amp. I have had a car with intermittant starting issues that gradually got worse over a few months. Initially just refused to start and keep cranking and it was fine once it fired. Eventually refused to start point blank. AA tested the ignition amp, said it was fine.

 

I tried its ignition amp on a car that ran fine, and no start...

 

Symptoms sound very similar. Pretty certain it is due to the sensor type in the dizzy. Its output is stronger the faster the engine turns so is pretty weak when cranking but a good signal once it fires. I think the ignition amp becomes a bit "deaf" so it no longer works at cranking speeds but if tested with a big signal looks fine.

 

Rob

[TEKNOPUG 3]

I'd say that it was the signal to the injectors to open that's at fault, as you have fuel pressure and spark, therefore I suggest swapping the ECU.

[Anthony 1,003]

If you're getting fuel to the rail and you're getting spark, then make sure you're getting fuel being injected - should make the plugs wet and you should see a sort of fuel "haze" from cylinder(s) with the spark plugs removed.

 

If you're getting fuel being injected OK, then it might be chucking in too much fuel and instantly flooding itself. Try to start it, and then unplug the injectors - if it fires up OK for a moment or two then overfuelling is your issue.

 

Compression check should rule out anything like a slipped cambelt or cam timing being miles out. Snapped cambelt would lose you spark so won't be that, and it sounds odd when cranking over as well

[Alastairh 47]

Well yeah Anthony from pre loom swap that what it was doing.

 

Wouldn't start, so cracked off the fuel and would start for a short period, then die. connect back up would run. then Say switch it off to take for a spin and wouldn't start again.

 

Its getting too much fuel i say.

 

Alastair

[Ben Allen 8]

Fixed it

It was the tachymetric relay. Turns out my spare tachymetric relay was also dead so it made no difference when I fitted it.

 

Got one from 205parts instead (cheers people) and it works fine now

 

Thanks for all the suggestions everyone, I'll see you on the ferry!