Having stalling issues!

[Kalahati]

Car: 1.4cl 8v 1997 Manual

My brothers Polo has been standing for a good 2 months. When he came to get his car it refused to start as the battery was dead.

Got it all charged, but now the engine runs somewhat weirdly.

It idles fine and revs up fine on partial throttle. But as soon as you go full throttle, the engine surges or just cuts out completely. It's perplexing as with little throttle it revs up nice and healthy.

I took off the TB and cleaned it to perfection, however, issue still persists.

I ran a VAG-COM/VCDS scan and it reported:

00533 - Idle Speed Regulator
08037 - Basic Settings not Performed

I tried aligning the TB through VAG COM but it just came with an error. The TB just made a weird noise for a short while and resisted any alignment.

I'm all out of ideas. What do you guys think?

[alexperkins]

The coolant temp sensor may have failed

It could also be a failing on the idle valve in the throttle body

[alexperkins]

Also, you need to ensure you clear the fault codes and then run the alignment otherwise it will fail with an error

[Kalahati]

The coolant temperature was the same on both VAG-COM/VCDS and the dash board. I don't think it's this. Perhaps a new TB is needed?

[Kalahati]

I did that indeed, however, it was still a no go. I made should I met every condition needed to run the TBA, but it refused to even with the requirements yet. Perhaps just a faulty TB?

[alexperkins]

Its possible. I have seen faulty TBs on these in the past

The only way to rule it out is to get a known working one and go from there

The coolant temperature can register right but the circuitry inside can fail (4 wires, 2 independent circuits)

[Kalahati]

Changed the temperature sensor but the issue still persists!

I'm going to try and unbolt the downpipe and see if it runs as normal just in case the cat-converter is blocked or any other section of the exhaust. Strangely, after starting the car from cold, there's a lot of smoke from the down pipe bendy section as well as from the backbox as well. I will have to investigate these.

Does a 1.4 8v have a MAF sensor? Thanks.

[alexperkins]

Might be a leak on the inlet manifold

No maf. Only a map sensor

[Kalahati]

I don't think there are any leaks, I'm going to replace the throttle body and see if that cures this problem.

Wish me luck!

[Kalahati]

Changed the throttle body yet problem still persists.

However, I noticed there is a continuous arcing from the ignition coil when cranking the engine. While its arcing, the engine refused to start, when it stops arcing, it starts perfectly.

When I full throttle the car, the ignition coil sparks again then the engine dies.

Definitely the ignition coil, right?

[alexperkins]

Could be a failure in the hallsender, distributor or ignition coil

Try the coil first.

Check all the earths are good too.

[Kalahati]

There was a crack on the ignition coil where the king lead goes in to, which was were it was arcing. I closed the crack using a soldering iron as its plastic. The arcing as stopped but he problem still persists. Under high rpm, the ignition smokes a little and it has a burning smell. I checked the cap rotar, plugs, lead etc and they all seem alright. They're somewhat new.

Definitely the ignition coil?

[alexperkins]

If it was cracked that's a sure sign that there's an issue there

Could be unrelated but I would say its a problem.

[Kalahati]

Ordered one, please let this be it.

[Kalahati]

The new ignition coil has cured me of the problems, and now the car runs pretty good.

Thanks for your help man. Can finally stop thinking about this car.