Cold start circuit diagram / description required

Hi,

My '86 1.8 GTi cabriolet is nearing the end of it's refurbishment. The whole fuel system from tank to injectors has been renewed and rebuilt but the garage now has a problem with the cold start circuit. They have described the problem as " we need a diagram to show where the wiring goes to and from the various items. I know the wiring from the cold start injector goes back to the fuse box so I need a diagram that shows specifically where it goes, failing that we will have to trace the wiring physically".

Can anyone point me towards a suitable reference please?

any help much appreciated

Jonathan
 

With the 5th injector thermoswitch in the flange on the front of the head, this has a red/black which is starter cranking live which goes to a 2 male pin spade connector behind the fusebox. The mating connector for it is a single pin female spade on the fusebox yellow plug C pin 18.

the thermoswitch green/white goes to the 5th injector, providing the earth for it. usually in the mk1 this goes from the 5th injector to the same 2 male pin spade connector as above behind the fusebox, then back to the thermoswitch. you dont actually need to plug anything into this spade though, it does nothing.

for the 5th injector you have a cranking live which is either red/black, or black. if red/black it goes to the 2 pin spade connector above as well, if black it goes to the starter motor terminal 15a.

Thanks for the response, sounds pretty comprehensive to me but I dont have the car here to put it into practice! I'll forward it on to the garage and see if it gives them what they need.

Much appreciated.
 

Just a quick Q about your document store, is there a naming convention that would let me filter on Mk1 Golf? I see 6n1 on some that I assume are Polo related?

cheers
J

I've got a mix with the naming convention, the older stuff will be mk1/2/3… or g1/2/3… then as I get to know the VW chassis codes I start using them so 6n for polo etc.

plus some of the diagrams are just named as found so golf91, jetta89 etc.  There aren't many mk1 diagrams about on the internet as it happens, I had to scan the pre-83 fusebox ones myself from the haynes. I'm planning to get the CE1 fusebox diagrams out of it at some point as well since no-one seems to have any of those either!

the jetta89.pdf is for the CE1 fusebox which is the same one as used in the later mk1 golf, so it has some of what you need.  plus if you check the mk2 16v wiring diagram g2krecuce1.pdf you can use that for the basic cold start wiring as its all the same for the mk1 CE1 fusebox

if you have the older ceramic fusebox then use the g1wiring81gti.pdf

OK, the garage are moving forward on this but have one question remaining:

Where does the live feed for the cold start injector come from please? They assume its from the ignition or a cranking feed from the starter motor. They think the wire is black(!) at the injector but it has 0.2V on the meter so this seems to be the point where the cold start is failing.

Really appreciative of the help so far this has moved us on a lot faster than having to trace every wire through the loom.

cheers
J

if the wire on the 5th injector (cold start injector) is black then it is fed from starter pin 15a. if its red/black then it runs back to a male spade in a 2 pin plug behind the fusebox along with the 5th injector thermoswitch red/black. Either way, it should see 12v when cranking on the starter as should the red/black on the 5th inj thermoswitch.

note the 5th inj green/white should only be earthed when the engine is stone cold, as soon as its been cranking for a bit or the engine warms the earth path is broken

Just a quick update here. The car's running perfectly now, the garage found that a wire from the starter motor had been cut and joined and the joining connector (I'm assuming a scotchlok) had corroded and broken the circuit. I'm collecting the car next week and then need to only locate a new roof, get the interior refurbished and then get the wheels sorted!

Many thanks for your advice,
Jonathan

good stuff

Rabbit69 said

I'm collecting the car next week and then need to only locate a new roof, get the interior refurbished and then get the wheels sorted!

Many thanks for your advice,
Jonathan

And so it goes….. One thing after another…
We have all been there… Shoot, I am still debating on an interior scheme… But the top, and all will be replaced again sometime later this month of I can get the time…

Yep, its a long term project, I'm not expecting it will be properly finished for years!. The cabriolet has the CC logo on the seats / door cards / roof lining so I'm hoping to keep as much of that as possible and where I cant I want to be sympathetic to it. 

Sorry, didnt mean that to sound rude. Just have a massive list of things I need to fix!.  Any advice / contacts / sources you can think of could be really useful. I've had the car for almost 10 years but only started to rebuild in May last year.