mk1 running problems

[malmac]

Hi,

Finally got my mk1 scirocco gti on the road but it aint running that well.

When you put your foot down it's quite sprightly and pulls well but when you accelerate more slowly it starts holding back and isn't very smooth.

Its had new HT Leads & dizzy.

Any ideas?

[the edmundator]

Mine does that. Ant suggested possibly throttle cable adjustment.

[malmac]

think it's something more sinnister than than, feels like a fuel problem although i'll still check throttle cable.

cheers

[Nate]

When I first bought my scala it was similar to that - ran fine if you gave it a decent bootfull, but coughed and spluttered if you were nice to it. Turned out to be the timing belt slightly loose. Worth checking, and if it is I'd be tempted to just bang a new belt and tensioner on it

[mark1gls]

Did you also fit a new rotor arm? Check timing and all the timing marks around the cam belt.

[malmac]

Hi,

Thanks for the replies, have checked all suggestions and ok my end.

When you first start car up it runs on 3 cylinders then on to 4, been advised to replace injectors.

I'll update thread with the outcome, hopefully on a positive note.

Thansk again.

[JDUB]

Worth a thought. It could be as simple as old fuel if it's been standing a reasonable time without use ?
Have you tried draining the tank and putting some fresh petrol in ? It would be worth adding some REDEX cleaner too, made a big difference to my carbed MK2 after a winters layup.

[malmac]

Good idea that, i'll buy some of that and see what happens. might just fill the tank up to help dilute any old spoilt fuel, never drained one before.

cheers

[JDUB]

That sounds like a good idea. Just adding the new fuel should make a difference but, if you do decide to go with the cleaner as well, I don't know what the difference is but there's a REDEX for carbed angines and a different one for Injected engines ? probably best to use the right one ? Round here it's cheapest in Wilkinsons, about half the price it is in the petrol stations.

[malmac]

gonna use injector cleaner in the tank aswell as filling it up with fuel, fingers crossed it will do the trick.

thanks again, i'll update my progress............

[malmac]

Still doin' my head in this motor, so far i have:

1) done the timing
2) put injector cleaner in tank
3) replaced injectors
3) new dizzy and ht leads

but i've still got the 'hot starting' problem, it instantly dies when you turn the key then takes a while to fire up again, just keeps spinning over. when it does fire up it's on 3 cylinders for a few seconds then onto 4.

It's still not accelerating as smoothly as it should when driven gently, fine when given a boot full.

Any ideas ??

[Nate]

.

[Nate]

Is this one points and condenser, or electronic?

Sure the correct dizzy cap and arm fitted, and fitted correctly?

checked engine timing (as opposed to ignition timing) correct?

tried unplugging 5th injector? (Could be overfuelling if it thinks the engine is cold)

[bensspares]

Sound to me like fuel starvation to me, that or weak mixture..

before you spend any more money, check the pick up in the tank isn't blocked and check if the system maintains its pressure....Ie run engine then shut down, leave for 10 mins then undo the feed pipe to the fuel filter and see if there is a squirt of fuel as the pressure is released...

[malmac]

Hi all and thanks for the advice,

Just to re-cap:

My cars electronic ignition, dizzy looks fine, i never got round to replacing rotor arm as they were out of stock, so i should replace it as cheap. With regards to 5th injector, i pulled it's lead out but didn't cure the hot starting unfortunately.

I also did that pressure test and after about 15 mins i got a good jet of fuel when i cracked the filter.

I'm watching a cheap metering unit on ebay in good working order to see if that changes anything, if it doesn't cure it it's getting burned out !!