Misfiring Twin Spark
I am the father of a son who recently acquired a 1999 Alfa GTV twin spark Lusso with the five circle wheels - after the V6 Mazda 323 ZXi he bought from me had met its maker rather spectacularly.
So he bought the car and went 300 miles to Darlington to get it and now its my problem....
It has done 79,000 and its basically OK but has not been serviced since 60K. It looks like a company car, filthy engine, round door frames, etc, but has FSH. it was last owned by a sales gorilla for a scaffolding company by the paperwork left in it. Lots of clumsy/ unnecessary minor interior damage - but nothing serious. Already cleaned up and shiny and looking more like it is cared for by proud owner.
I can usually fix everything except stuff needing specialist diagnostic garage equipment, a pit or heavy tools. Even change ECUs and throttle blocks, drive shafts, suspension, etc. I avoid the big and protracted stuff - no garage. I look after 5 cars.
So the Alfa came back from Darlington and ran for few weeks fine. It has some slightly loose rotating rattles (variator belt he was told) but nothing nasty obviously related to the crank, pistons, valves, cam, etc. The lad is going to get it serviced at a local Alfa specialist (Thoroughbred Cars of Laleham)..
But it has started misfiring suddenly. Not when stone cold but as soon as warm. I guess an ignition coil. It feels just like when my SAAB 9000 direct ignition failed. Do they fail at this mileage.
It idles smoothly - with no missing - but hesitates and then misses on probably one cylinder when the accelerator is depressed (load?).
My guess is one of the direct ignition coils. But I guess an experienced Alfa Twin Spark owner already knows what this is?
Have already had the top cover lid off, no visible sparks. I now plan to disconnect the LT leads to each coil one by one and see which one has the largest effect to maybe isolate the culprit.
Having seen what the twin spark arrangement does I have to find out how it works......
I have also given him some injector cleaner in case its that, but I doubt it if they work at idel OK..
Last edited by alphabravo; 23-06-08 at 22:06.