SPICA microswitch

[dcalfa]

I've had a steadily worsening problem on my 78 with several symptoms, including lots of popping/backfiring on deceleration in gear, a lot of whiffs of gas smell, some weird starting behavior and excessive gas consumption (12 mpg if i'm lucky). Plugs are clean, no gas in oil, etc. None of this was happening a few months ago.

An experienced Alfa mechanic tentatively diagnosed it as a bad or going-bad microswitch on the SPICA (continuing to feed gas when it shouldn't essentially). He says it will cost 700-900 to fix all told, but I see the part is only $52. Does this sound reasonable? Can a non-wrencher like me handle it or does it require too much followup adjustment? (I usually limit myself to peripheral and cosmetic stuff since I'm no mechanic and don't even have a garage) He hasn't steered me wrong before but this seems excessive

[Wolfman]

Actually you can fix the "fuel solenoid" yourself, you can even test it. Get a good maintanance manual and some basic good quality tools to do the job.
A good manual will also show you how to set up the Spica correctly. While you are at it, check all your fuel lines for cracks (use a correct "injection fuel line" connecting to your spica pump to handle the high pressure) and check fuel pump and filter for "dirt". These are basic things you can do yourself and will save you money, head aches and lots of fuel.

I had the same problem with my 77' with Spica, which is now running 24mpg, even with engine mods. Apparantly your mechanic did not want to do the job, so therefore a very high quote.

[Roadtrip]

A bad microswitch might cause some backfiring or popping. However, if the car is in tune, the microswitch isn't really essential. The microswitch in my injection pump has been inoperative for a couple years now and the engine does not pop or backfire. Next time I have the pump off the engine for something else, I'll replace it.

More likely the problem is a Thermostatic Actuator going bad on you. It causes the mixture to be way too rich once the engine is warm and thus the backfiring. The plug would also probably show a very rich mixture.

If you'd like the Spica manuals, PM me an email address.