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Re: [alfa] looking to borrow or buy a Jetronic ECU for 3L Milano Verde



Just guessing, but what is supposed to happen if the O2 circuit fails in a 
way that says the mixture is very lean? (I forget wether low voltage or 
high is the lean signal) If it is low, then maybe an open in the O2 sensor 
circuit would give 0 volts and signal the ECU to supply more fuel.

I am sure there are some on this board that know in detail how this works.

Gwynne Spencer

At 09:57 AM 11/17/2004 -0800, you wrote:
>I've been trying to troubleshoot an annoying and very very intermittent
>fault in my 3L Milano Verde. The basic difficulty is that it has a very
>infrequent driveability/stall condition, and since it happens rarely, and
>then clears up magically on it's own, it's been really hard to diagnose.
>I've been driving around with a scope on various signals - as best I can
>tell for several seconds it likes to run the injectors at 95% duty cycle,
>then magically restore proper operation ( it's not the overrun fuel cut
>off - that works right, and my problem is the opposite - it wants to flood
>the injectors ON). I've watched the AFM and temp sensors during these
>transients, and they look just fine.
>
>This is happening infrequently, say a couple seconds a month, and has been
>a longstanding situation ( like 10 years). But I'm motivated to really fix
>this - it has gone from a couple hiccups a year to several times a month.
>If it really is in the ECU it is something which fixes itself. I've banged
>and shaken the ECU with no result, and looking at it it looks
>well-soldered, etc. I haven't tried freeze spray or a heat gun, though.
>
>I'm wondering if anyone has a good Jetronic ECU for a 3L, which I could
>either buy outright or rent for a couple months of driving to see if
>changing the ECU changes the behavior. Let me know - John Fox (
>jdfox@domain.elided)
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