Alfa 33 Bosch electronic ignition problems

[ScoopJumps]

Hi,

Sorry if this is the wrong place but I couldn't find a technical area to post this...

I'm really hoping someone can help me out here.

At the end of last year, as some of you know, I purchased an Alfa Romeo 33 8V racing car. When I bought it it still had the standard wiring loom in it. This seemed like madness to me so I ripped out the old loom and rewired the whole car myself.

After doing this I couldn't get the engine to start. I had no spark. After much head scratching I decided the best bet was to buy a new amplifier. I did this and the engine run. It was tuned up and driven and seemed ok. Sounded like a bit of a misfire but put that down to poor quality fuel and running a bit wet.

On going to restart the car its not working again. The dizzy has been tested and is fine, new HT leads, rotor arm, dizzy cap etc. Then I recalled I hadn't replaced the ballast resistor I had removed when I took the loom out.

What I suppose I'm hoping to hear is that me not running the ballast resisitor has fried the two amplifiers. Would it do that? The only other thing I can think of is the signal cables do go close to an HT lead so I shall use shielded cable and rewire those as well.

Anyone got any ideas or can confirm/deny my suspicions? Its doing my head in and costing me money everytime I get it wrong

Many thanks,

Sam

[GORDON STREETER]

Not being familiar with the Alfa ignition system, But I do know that if you run ballast resistor "coils" without the resistor in line they will burn out pretty quick as you are sticking too much juice in to them , it will also make the engine misfire ! . Being lower voltage than the battery the 9v coils only receive the higher volts via the starting system when starting. If you run an alternator it will be even worse as its approximately 14v and will cook things pretty quickly !

[inamo]

Might be worth asking the folks here: http://www.arcaforum.com/

[ScoopJumps]

Thanks Gordon,

Do you mean the amp will cook or the coil?

inamo - Ta, I did post on there but got told some weird **** about an Italian summer which made no sense at all.

[GORDON STREETER]

I actually stated "coils" but as I said I am not clued up with the system used on the Alfa. So in this case I may be talking b******s (it wouldn't be the first time)

[ScoopJumps]

Thanks mate,

I just can't think of any other reason why it would fail after a period of time. Its definately not a wiring issue, plus it wouldn't run at all if that was the case. Pulling my hair out.

I think my best bet is wire a resistor in line and shield the signal cable from interferance and see what happens. I ****ing hate electronics. One tiny black box on the whole car and shockingly it breaks!

[Al Weyman]

Funny enough I have just been playing with electronic ignition on my Chevy and although may not be relevant here I did find a nice easy way to test the system off the car which may help. In my case its a modified GM HEI distributor with MSD amplifier and rev limited and MSD coil built in to the dizzy cap and all reprofiled and rebuilt to match my engine (well meant to be!). Anyhow it was working OK when the engine let go and is virtually new and now I have put it all back together I cannot get the thing to spark or fire up. Now cranking a new V8 over to try to test for a spark can be a pain so I decided to pull the dizzy out again and try to bench test it. When I was pulling it out I noticed a rattle in the cap, pulled the coil cover and discovered one of the bolts that hold down the coil floating about in there (thanks FBO systems in the US!) worse still it was the one that anchoured the earth wire and you could see the wire had been arching out so problem hopefully solved but I still wanted to test it as its no mean feat putting it all back in and routing the HT cables etc.

So what I did is get a pair of jump leads one to the dizzy body and to negative, connected an HT lead from the cap to a plug and ran another jump lead to the body of the plug and to negative. Then put a positive feed into the dizzy and wearing a nice pair of rubber gloves (big whack on these modified HEI dizzys!) spun it over by hand and presto nice fat spark in fact as soon as I spun it I could hear it popping in the cap as the spark jumped to the terminals. So maybe a nice way to test yours off the car to save a bit of grief. Just got to try to start the car tonight now! My mechanical period was way back in the points dizzy era where what you see is what you get and diagnosis is much simpler (I have left that side complete with external coil intact on the car BTW and take a spare points dizzy with me to the track just in case) so it was nice to find a positive way of testing one of these gizmos off the car.

BTW on the wiring side and during my research they did say you need a 14 guage wire to feed the system which requires a full 12 volts and sometimes another feed from the main terminal that kicks in when cranking the engine to ensure the full 12 volt hit.

[knighty]

sam - is your engine an alfa-boxer flat-4, the 1.7 version......what year is it?.....mechanical or hydraulic heads?.......I have just installed a 1.7 8v alfa-boxer from a G-plate sud into the back of my buggy and I'm concerned this problem will hit me too........please let me know........I have asked the question on the www.alfa-pages.co.uk site too, they will know for sure.

[ScoopJumps]

yeah its a 1712cc boxer. As for the heads... forgive my ignorance. I bought the car and havent fiddled with it (apart from the electrics) so couldn't tell you.

EDIT: Oh, it is an 8v