Cold start testing

I need to get a MOT on my 1.6 GTI tin top. It failed on emissions. The garage said the 5th injector was constantly on.

I've just tested the thermo swith. Pulled the plug off the 5th injector put a multimeter on the connections in the plug. Grounded the king lead against the engine block and had someone turn over the engine.

There was no voltage reading on the multimeter at all. What do I test next? Surely if there was no voltage then the injector would be perminantly off? The garage were grumbling about the wiring in the engine bay. But the wires that weren't connected are for the temp gauges in the cockpit not part of the CIS.

Thanks for the help

Dan

Hey Bud,

I know it's a late reply.  Might be that the 5th injector is actually leaking.  Take it out with the fuel supply still attached.  Plug the hole in the manifold and with the engine running verify fuel isnt leaking from it.  Might be the injector that's dirty, not seating properly and sue to the fuel pressure its causing it to dribble and supply some fuel even though it's not getting a signal to do so.

Mike

 

That is one possibility, as the spay of the 5th injector is more like spraying Ether in to the carb.

if you do remove it get new seals and use Berrymans B-12 to clean it.  This is more a product of the WUR needing a tad bit of clean up of the contacts, IIRC they make a WUR kit that you can rebuild it.  Where a lot of folks that I have seen take it apart and clean it up to restore proper functionality of it.

But since your above post is a iffy Battery issue I would suspect your Grounds or Power side to be the issue that I would look in to first as iffy grounds cause a whole lot of strange things to happen to electrics, and the simple
cleaning connectors and such eliminates a whole lot of electrical gremlins from getting prodded to cause oyu grief.

Read the Riddle in my signature, as take if fro some one who's whole career was working on High Voltage/Computers….I have seen electrics to really strange things if grounds and such aren't perfectly operational… I got a 10,000.00 dollar check from some one who wouldn't believe me over the Phone that he had a ground fault on his network….A 5 hour drive and a quick check with a meter proved that his 3 servers all had different grounds and that by plugging in his network cables between them caused all sorts of issues.