Mk3 Gt Engine Problems

Baredd · Post by **Baredd** » Fri Apr 15, 2005 11:04 pm

Mk3 Polo Gt Coupe Sat in the car engine running fine. Revs drop so I rev it happens sometimes fine. Pours down and I mean pours with rain and I turn engine off, 2mins and yes 2mins later it wont bloody start.

Ive tried:
New distro cap
Clean rotor arm
Clean spark plugs
clean HT leads
check battery
bump starting
jump starting
check every visible plug for water
check oil
check temp
check water levels
full tank of fuel
had a new fuel tank, filter and pump 6months ago
fuel getting to engine as spark plugs stink of it
check exchaust for blockages stinks of unburnt fuel
so, pulled HT leads out stuck screwdriver in end, touched screwdriver on the rocker - no spark...

SO ANY AND ALL IDEAS WELCOMED!!!!!!!!! Car not even at my house so sooner the better

GroovyCarrot · Post by **GroovyCarrot** » Sat Apr 16, 2005 8:50 am

Have you checked the ignition coil? Sprayed WD40 on all electrical contacts in the ignition system?

Tahrey1043 · Post by **Tahrey1043** » Mon Apr 18, 2005 8:44 pm

ok i know i go mental over these little bits of copper and rubber, but.....

when you say "clean HT leads", do you mean you cleaned them, or replaced them with "clean" i.e. new parts?

GroovyCarrot · Post by **GroovyCarrot** » Mon Apr 18, 2005 10:31 pm

Tahrey1043 wrote:ok i know i go mental over these little bits of copper and rubber, but....

<Pedant mode>
Silicone and rubber.. unless he's got something very wrong whilst ordering parts.
</Pedant>

Apologies.

D4V1D · Post by **D4V1D** » Mon Apr 18, 2005 11:00 pm

blue temp sender

minis84 · Post by **minis84** » Mon Apr 18, 2005 11:57 pm

if there's no spark at the plugs it definitely sounds like the coil.

If its in the same place on a GT as a 1043 CL then it will be on the nearside inner wing near the headlight. If the bonnet was open when it rained then its likely this is wet. Spray some WD40 or GT85 onto all the connections, then try it.

The only time my Polo ever stopped was due to me driving through a ford a bit fast and getting the coil wet. A quick spray and it was sorted.

Tom

Tahrey1043 · Post by **Tahrey1043** » Tue Apr 19, 2005 8:00 pm

GroovyCarrot wrote:
Tahrey1043 wrote:ok i know i go mental over these little bits of copper and rubber, but....
<Pedant mode>
Silicone and rubber.. unless he's got something very wrong whilst ordering parts.
</Pedant>

Apologies.

I thought it was a copper core with a silicone rubber sheath..... I.... I... I.......
*head explodes*
*headless torso goes off to root the old Beru box out of the garage to look*

certainly doesnt look like silicone at the end. isnt that stuff non-conducting?

In any case, cleaning them shouldn't do jack sh** if they're in good condition, as, after all, they should be watertight and whats on the outside shouldnt matter.
Blow Â£30 on a new, good quality set if you're feeling flush and haven't already tried it. Might clear the prob up. Don't go for Hotwires whatever you do. And only Halfords if you can't get OEM grade stock (they're decent when brand new, but they can't measure an accurate length of cable to save their souls, and the stuff doesn't last as long)

GroovyCarrot · Post by **GroovyCarrot** » Tue Apr 19, 2005 8:13 pm

Copper cored HT leads haven't been used for years, they burnt out quickly and weren't terribly reliable. I imagine it's a compound involving silicone that they use in new leads, but it has a very high resistance up to a certain point (about 6-7 kOhms I think), but conducts well at high voltages. Much more reliable and long lasting than the old copper leads.

Tahrey1043 · Post by **Tahrey1043** » Tue Apr 19, 2005 8:53 pm

coo eh.... thats a mighty fancy thing

learn summat new every day or your dead was my grandads catchphrase (..was..)

GroovyCarrot · Post by **GroovyCarrot** » Wed Apr 20, 2005 9:24 pm

In the name of science, I decided this afternoon to prove that silicone cored leads do indeed conduct electricity extremely well, by unplugging one with the engine running. Somehow the current managed to bridge the gap between the end of the lead and my fingers and earth itself through my body - that's a lot of voltage. And it bloody well hurt

Maybe I'll listen to the sticker under my bonnet warning me of high voltages in future...

optima21 · Post by **optima21** » Wed Apr 20, 2005 10:23 pm

erm I understand that copper isnt used as the conductor because it causes interference with radio, due to electro magnetic emissions. Hi performance racing engines still do use them .

the silicone on modern leads is the outer casing and its the insulator. the conductor normally has a high proportion of carbon in its core to conduct the electricity.

GroovyCarrot · Post by **GroovyCarrot** » Thu Apr 21, 2005 1:37 am

How odd.. why would you classify a lead according to the insulating material? Especially when copper leads are classified by their cores?
I didn't realise copper was still used in performance engines, but I think one of the main reasons that they stopped using them in regular cars was that they burnt out very rapidly, although I'm sure as you say they were particularly bad at causing interference.