Omega Owners Forum
Chat Area => General Car Chat => Topic started by: cam.in.head on 03 November 2023, 18:06:31
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hi. all .the jetronic efi system fitted to many 1983-1986 vauxhalls such as senators and carlton 2.2's have a variable idle air valve controlled by its own seperate ecu.these ecu's often fail and cause issues. looking inside them pretty much reveals nothing of note to suspect and close examination of solder joints and replacing capacitors doesnt solve anything.
swapping the ecu with a known working one makes everything ok again
SO
do we have any experts on these ( or a known link to any sites that do ?)
ecu repair facilities dont reply (obviously as they want the work !)
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Post a photo of the internal boards and I might be able to tell you how to fix it. If the semiconductors are standard parts they can be replaced.
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il try and open up the old one and send a photo to you . dont think il be able to post in in my post ?
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If the engine was also available with a carb, do Holley produce a bolt on injection kit for it? Or could something from a newer Astra/Cavalier be made to work?
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yes i was wondering wether other cars used a similar setup but i think later stuff was another form of jetronic or motronic where the idle speed control was incorporated in the main ecu rather than a seperate box.carlton mk3 for example but like some omegas they use a 2 wire valve anyway so not the same .
there are many 3 terminal valves listed on ebay for various other cars such as vw,bmw,jaguar etc so they MAY use a seperate ecu ? im still digging around the internet but it seems hard to find any relevant info with most idle speed issues been related to the control valve rather than the ecu which is not the case here. proven by substitution.
i have a working ecu on now and the other ecu swaps symptoms to other car so its definately something in there !
i may have to just resolder every joint and replace every electrolytic for starters and go from there
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I was thinking along the lines of updating the whole system... ;)
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Like you I'd be sceptical of most repair places having any kind of test harness for such a thing these days, and therefore unable to say they'd "fixed" it versus they'd "opened up the box, had a poke around and done some basic electronics checks". You're needing to confirm both the hardware and the functionality, not just kicking the tyres.
All my random googling efforts last night amounted to not a lot more than what you've already got. The most extensive thing I found was your own thread on a Manta board - I won't bother post a link for you ;D Couldn't even see a pinout or circuit diagram. Is there a Haynes or GM service book for the Carlton/Senator/Monza? I'd searched on the "Bosch 0280220028" part number that gets banded about, before I noticed that was 2.5 and 3.0 specific and flipped over to "Bosch 0280220019" for the 2.2. I tried looking under "leerlaufregler" to see if I could pick up any of the Opel-derived mentions across Europe. Nowt though. Even searches on the usually trusty motor-talk.de (https://www.motor-talk.de/) proved fruitless. Maybe at a push you could track something down to at least give you a steer using all the different part codes for item 39 here - http://www.senator-monza.de/?MTPElERNZiMyETPElUTT1kJzUjNx0DRJVUTTZSM5ITM8NDOyEDf0EzM9EkUBBVT (http://www.senator-monza.de/?MTPElERNZiMyETPElUTT1kJzUjNx0DRJVUTTZSM5ITM8NDOyEDf0EzM9EkUBBVT) Aha, at least they have some wiring diagrams available it seems - http://www.senator-monza.de/?wM9QUSE1kJzMTPElUTT1kJ5UzM9QUSF10UmMjM9EkUBBVT (http://www.senator-monza.de/?wM9QUSE1kJzMTPElUTT1kJ5UzM9QUSF10UmMjM9EkUBBVT)
And then slight improvement as I'm typing - is this a wiring diagram for the Jetronic on a Z22E with a leerlaufregler at K40 ? :D - http://www.senator-monza.de/daten/2/2/bilder/Bilder%20Einspritzanlagen/Schaltplaene2020/Z22E%20Jetronic1024.jpg (http://www.senator-monza.de/daten/2/2/bilder/Bilder%20Einspritzanlagen/Schaltplaene2020/Z22E%20Jetronic1024.jpg) It's a big assumption on my part that's even the engine/year/ECU combination you're talking about, but at a glance the pinout seems to match the numbers on the ECU casing that I've seen in pics.
Given all of that and the fact that you're progressing down the 'verify/replace the components' path, plus the fact that you've acquired a second working ECU (until it too fails), as a longer-term pastime for my own amusement I'd adopt a different tack. If you're able to measure the known inputs and outputs on a working ECU, one might perhaps be able to reverse engineer a map if it's a linear change. Then 'quickly' knock something up with an Arduino derivative to mimic that. Far, far easier if you had any kind of better source material to work from though, I grant you. But given the seeming cost of unknown provenance ECUs, I'd spend minimal cost and chuck some evenings at it, and give it a go :y
Cheers, Stu
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hi stu and thankyou very much for your detailed reply and obvious time spent researching as well.
the working one which is perfect and the one that went recently faulty have both been studied very carefully .one was for a manual and one was for an auto (no's 0.......017 and 018).both do identical functions except hold a different idle speed.
i spent a few evenings looking for differences in the two and found 4 resistors different to each unit. i swapped these from unit to unit and also replaced the electrolytics in the good unit too.
so far i can confirm that the resistor swap worked. the manual ecu now holds auto idle speed and vise versa and both units ( including the faulty one ) are working ok so far. i did resolder loads of joints even thou they looked ok but as you know some cold joints are not always visible.
pm sent too .cheers.