my golf gti mk1 is misfiring when start in morning.?

Question

my golf gti mk1 is misfiringwhen start every morning, but after couple minute on the road, its seem better but the car still under power.what is wrong with the car? pls help !! any suggestion with appreciate. thanks you.

Answer 1

First question I'd ask is "is it actually misfiring, or is it just running rough?"

Is it a regular misfire (on the same cylinder) or random?

It might also be a fuel fault, if it only does it when it's cold I'd suspect the cold start injector or some associated part of the cold start enrichment system.



That car has a fairly basic fuel injection system, it should be a relatively straight forward process to trace the fault. Try one of the VW forums, you'll find a lot of knowledgeable people on them.

Answer 2

First thing I'd do is renew the distributor cap and rotor arm,genuine parts if you can afford them,then the HT leads and spark plugs.

check for any vacuum leaks from the inlet manifold small bore pipe that runs to the distributor vacuum capsule,they're cheap enough to just renew them.

And I'm going to assume that the fuel filter is new,same with the air filter?

Then if it still persists then I'd be looking at the fuel pressure and the thermotime switch.

There is no check engine light on that car with its age so if you get stuck then you will have to find a real mechanic,either somone over 40 or a specialist,those old time mechanical fuel injection systems can be a little tricky.

and hope no rust from the tank has got into the fuel distributor manifold.

that was a killer even back then!

Answer 3

Your check engine light should be on and in that case you should take it to a mechanic and pay the 60 dollars for and engine diag, even if the light isn't on, you should still get it checked and it should be the same price. There are just too many things that can cause that and you will spend more time and money chasing it down than what it would cost for you to atleast have a mechanic diagnose it for you. Just a few things it may be though, fuel pump/clogged fuel filter (not producing enough pressure), ignition (morning dew will often find its way in distributors and things), tps (throttle positioning sensor may be giving a bad readout), vacuum leak, due to the difference in temperature from cold start to normal engine temp it can be a load of different things and a could make a list a mile long explaining it and without actually being there to look at it its too difficult to tell. Just try a mechanic, and don't waste your time with some cheap AutoZone code reader, those things are almost useless, you want a full computer diag that will read ignition, air flow, fuel flow, air/fuel pressure, and vacuum.

Answer 4

Could be poor fuel flow / blockage some where. I would check your fuel filter. Possibly run through some treatment additive along with a fresh tank of fuel. A vacuum leak will also cause a vehicle to run worse, leading to starting issues & loss of power.

Answer 5

Several possibilities here, to me it sounds like a failing spark plug or lead. That's certainly what I'd check first.