Backfire, lack of power, cutting out

Hello, 
Ive been having trouble with my mk1 backfiring then cutting out, after a few minutes it will start agian and be fine sometimes for only 15 minutes sometimes for a couple of days! It does it when engine is hot or cold.
Could it be due to the immobilizer switch ive wired from the tci unit? I have used good cable and a 30amp switch.. It starts and runs perfectly..
Or does this sound more like fuel problems? 
I have checked the timing with a timing light, replaced the dodgy ht lead i thought it may have been but still no joy.

Theres definitly fuel at the filter with good pressure. 




Any help would be much apreshiated 




Thanks  

Hey there, sounds like you have a mixture issue. Backfire/loss of power is usually because you're running "too rich". Unburnt fuel ignites in your exhaust system causing it to back fire. Also, check your air filter. If you have a dwell meter laying around you should go to http://www.cabby-info.com/cis.htm and try adjusting your mixture. But be careful, because if you get it wrong you may get to a point where you need a new engine….

Good luck!

Would help if you tell us more about the car, carb or injection? What year? What engine code?

Sorry yeah, its an 82 gti running a 2.0 8v dx head 3a audi bottom end still running kjet injection

Cheers