Random GTI running fault

[forbeslongden 32 13 Cars]

Hey all, I was driving my 205 GTI on the motorway the other day and noticed that I was getting a 'hiccup' from the engine every now and again and after a while the car began to lose power for a few seconds, if I pushed the accelerator to the floor it would then come back eventually and drive fine again but every ten minutes or so it would either hiccup again or lose the power once more, this certainly made for an 'interesting' (read, scary) drive back on the A38! Can any point in the direction of what maybe causing this? Fuel related possibly? 

Thanks in advance 

[trashy 1]

DId the engine bay get wet?  Water in a spark plug well?

[Telf 224 2 Cars]

sounds like ignition/spark related- check all the usual things, sparks,plugs,dizzy rotor arm. Mine had a hiccup type fault- it was a crack on the rotor of the dizzy. is it misfiring or popping at all?

 

[jackherer 543]

Add the ignition amp and the signal wire from the dizzy to that list too.

[forbeslongden 32 13 Cars]

5 hours ago, trashy said:

DId the engine bay get wet?  Water in a spark plug well?

Not that I'm aware, I could well have a look at the plugs though as I haven't touched them for a good year or more

1 hour ago, Telf said:

sounds like ignition/spark related- check all the usual things, sparks,plugs,dizzy rotor arm. Mine had a hiccup type fault- it was a crack on the rotor of the dizzy. is it misfiring or popping at all?

 

My dizzy has always had a slight bit of oil collected in the cap, I get a slight pop ever so occasionally and usually coming down gears laying off the pedal.

 

1 hour ago, jackherer said:

Add the ignition amp and the signal wire from the dizzy to that list too.

Yeah I remember that my compound behind the amp is a little crap, the car doesn't often start first time when cold, it'll have nothing on the key aside the electrics and after 3 or 4 frantic turns it'll crank and fire into life

[jackherer 543]

The non cranking is a classic 205 fault and nothing to do with your other problem!

 

Check the wiring to the starter solenoid and the brown multiplug it is routed through. Also check the battery terminals and the ground wire on the gearbox.

 

That wont affect running though, you should change the ignition amp thermal compound and fix the dizzy oil leak to rule them out. Problems like this are infinitely harder to diagnose when you have more than one fault so fix the things you know about first.

[PhilNW 44]

Can be a sign of low fuel pressure check the pump pressure they don't last forever

[forbeslongden 32 13 Cars]

I've picked up some thermal compound first as I have a spare ignition amp, I think a look at the sparks and leads as well since that's all cheap. 

I certainly need to replace the fuel pump at some point as I have no idea how long this one has been in service for. 

Bloody petrol 205s and their gremlins

[AlexRS2782 136 1 Cars]

I feel your pain - had similar this afternoon on the way home when the car hiccuped then cut out at 50 and i coasted to a halt onto the verge at the side of the A331   Not run with a massive truck bearing down on you even with the hazards flashing away 

 

I had the plugs, leads, rotor arm, dizzy, etc, changed on mine earlier this year so (hopefully) can rule those out and will start looking at the ignition amp, any related wiring & also the fuel pump side of things as those are probably the only remaining original-ish parts i've never replaced to date.

 

Ran fine in the hot summer - colder weather sets in and mine seems to have complained - i don't think it want's to be used at this time of year 

[steve@cornwall 100]

simple check, make sure the connections to the coil are tight and not corroded.

clean the contacts in the dizzy cap and rotor arm.

[PhilNW 44]

My money still on the pump but try using some of the inline spark plug testers (halfords have them) to see if you are losing spark as it happens

Edited November 2, 2018 by PhilNW

[Roeland_Vester 5]

Keep a close look on the tach. If the needle moves erratically during the hiccup it's definitely in your ignition.

[forbeslongden 32 13 Cars]

Well I took the car round the block after putting some thermal compound behind the ignition amp, I changed the throttle sensor as well as I had a spare, more alarmingly, I found my SAD was unplugged so I connected it again and it ran fine. I'm hoping it's sorted it now as I've put her up for sale! 

[Gaz205 50]

I had a similar fault cured by having my injectors cleaned after I did everything you have done as well. Kinda glad as the next on the list for me was a fuel pump.