Hot starting problem .. tried everything !

Hi all,

First post so be gentle please
Got a hot starting problem on my 1.8 Mk1 GTi, and checked the Cold start valve and warm-up reg (both working fine), wired up a switched feed to power the fuel pump and even unplugged the Auxiliary air valve but still takes 20-30 seconds of turning over before it'll start when the car has been left for 10 or so minutes. The car will always start eventually, and starts first turn of the key when cold but infuriating and embarrassing when hot ..
I've replaced the injectors, fuel pump, accumulator and countless other bits but still not made on any impact on the situation.
I wondered if the replacement accumulator was duff but isn't it unlikely to give exactly the same symptoms as the last one ? Other thought was evapouration in the fuel lines but have run the pump for a five or so seconds before trying ignition and still no difference.
I'm going to swap out the distributor next with a spare one but it seems like a fuel problem to me .. any ideas gratefully received !

sounds like my problem but I'm convinced it's leaking injectorss on mine  :dontknow:

have you tried repleacing the Fuel metering/distribution unit?

must get my injectors out and test them  

Thats the next thing after the ignition distributor to be changed but it all works fine when its running apart from once when it all died in Coulsden which lead me to thinking it may be an electrical problem .. so infuriating though ! I've also replaced my tank to fuel filter fuel line with flexi hose but noticed no difference after.

when it starts does it sound lumpy like it's running on 3 cylinders?

mine has definately got worse because now for the first minute of running it's really lumpy

I don't think it'll be the ignition distributor as it wouldn't run fine

…had exactly the same prob, a new hall sender fixed mine - but wish I'd gone for a replacement dizzy - would have cost only a few ???? more.

Prowler, would a faulty hall sender also cause erratic running?

PhillTMK1GTI said

Prowler, would a faulty hall sender also cause erratic running?

…possibly….as it was explained to me by the auto electrician, the hall sender can 'break down' when it's hot, giving bad starting, and bad running if it's really bad…..all I know is that once he replaced the hall sender my GTI started 'on the button' every time, and still does.

I did have a bit of intermittent rough running after, but that was down to a jetting injector, hence my injector test.

I see, there you go Tyler, hopefully you have the same problem and your spare distributor will sort it out

I'll have to source one and see if it fixes mine

Tried replacing the electronic brain today but no difference, also gave the dizzy and 3-pin connector a thorough spraying with contact cleaner but still no dice. To be honest, I'm starting to wonder if it is electrical since it's never died since that time in Coulsden (nor before) and it runs just fine once it's started.
It'll start fairly easily if it's only been turned off a minute or so but any longer than 5-10 minutes and it takes a good 30 seconds of cranking.
I found the air flap was way below the conical part on the metering head and wondered if that may have affected the amount of fuel that would be drawn in at start-up (especially with the extra pressure from the WUR once it's warmed up) but no difference after bending the spring a bit to make it seat at the bottom of the cone either.
Timing seems fine but it does run on for a second or so if I haven't turned the fuel pump off before the ignition but thats the only thing I can think off that might be wrong on the car.
I'm stumped .. anyone got any other ideas ?

have you done an injector test? I know they're new but they could be leaking causing the engine to flood making it difficult to start after a few minutes

Thats on the list but I pulled them out of a car (that went to the scrappy, despite the new injectors that worked and started perfectly so doubt that would be the case. I'm wondering if my injector seats are up to par since I think one or two may have been damaged from my previous injector swaps leaving air to be drawn in at this point. Can the plastic or ceramic (or whatever they are made of) bits in which the injectors sit be replaced ?

ta again

Did the injector test (which was fine - they all flow pretty much the same amount of fuel) but noticed after pulling them out that the plastic seats in which they sit are broken on 3 out of the 4 injectors .. not sure if this would affect the start up to the degree where it won't start when hot but guess it'll need fixing anyway.
It looks like an allen key job to get them out, any idea what size please and if they can be got at without pulling the inlet manifold off ?

Thx again

think your right that the broken seats wouldn't cause the hot starting problem, would more likely effect the overall running

I have no idea how these come out.. do they not just pull out?  :dontknow:

Got some new injector inserts as they're known to VW, but am still searching for the right tool to get the old ones out now

No change in the hot start problem after changing the inserts and metering head .. thinking of changing the engine now