Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: V6Astra F on 10 February 2010, 17:16:09
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Hi
How are you guys doing ? . Been a while since I have been here . When was on here last my car still had the x25xe installed . Now im running a Z32se from a Vectra C :) . Im still using the Motronic 2.8.1 ecu from a Omega B .
Heres my problem when you drive the car and the fans kick in its fine no powerloss or hesetation . But as soon as you switch it off and start it again with the fans comming on as you start , it hesetates and feels like it does not have any power :( . As soon as the fans go off its better . Thinking that it might be my ECT/CTS sensor acting up . Anyone had something like this before ? . The EML light does not come on and I have no error codes stored .
Thank You
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I was mistaken does it when you are driving and the fans kick in . Going to swap out the CTS sensor with the spare one I have at home . I will post the part number to confirm that I have the correct one
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It sounds to me like the fans are drawing current through either a dodgy chassis ground or a supply circuit that's also shared with something sensitive so the current flow is upsetting the engine management system.
Try, as a first step, measuring the supply voltage(s) - permanent and switched, and the ground pin voltage at the ECU with the fans both on and off relative to the battery negative terminal.
If you can get something that can read live data off the ECU this would also be a useful step. See if any of the parameters are changing.
Also make sure that any supply or ground connections to engine management sensors are taken back straight to the ECU connections rather than being connected to local ground points and supplies. How they are in the factory loom, in fact.
Kevin
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:)
Will check my ground connections this weekend , I can use my laptop with a generic tech 2 and "My Naff Code Reader" to check the supply voltage . Will give you guys feedback as soon as I have done it .
Thank You
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:)
Will check my ground connections this weekend , I can use my laptop with a generic tech 2 and "My Naff Code Reader" to check the supply voltage . Will give you guys feedback as soon as I have done it .
Thank You
Have a look at coolant temperature, Throttle position, Mass air flow and the Lambda sensor readings while you're there. :y
Kevin
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Just checked it , I cant see any drop in voltage . But I did notice that the fan comes on when the coolant temp hits 106degrees :o , and only my one fan comes on . The AC was removed so the other fan does not come on , will connect it with a relay that it comes on together with the other fan . And try to get another switch for the fan , maybe one that switches on at a lower temp . All the other readings MAF and tps was normal .
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when the fan kicks in the current it pulls is large have you got a large enough alternator,also the two front fans are aircon ones.but deffinatlly check all earth connections,
chassiss to block,
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Going to check the earths tomorrow , I have a 140A Alternator its the one I got with the 3.2 .
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I had something similar with my 3.0 . The engine would get up to ~100 then the main fan would kick in full blast accomapnied by a massive drop in revs.
Turns out a fuse had blown and the fan wasnt coming in at low speed at ~92 deg. So nothinghappened until the engine got too hot and the fan kicked in at high speed drawing lots of juice.
Replaced the fuse, problem solved. A few weeks later the battery gave up. So the final diagnosis was that the high speed fan was cutting in drawing mega amps from my very tired battery which then dropped the voltage causing the engine to falter.
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Just checked the system , looks like the one switch on the radiator is loose its the top one with 2 wires , if you bypass it both fans come on at a lower speed . Going to see if I can find a replacement one tomorrow . Will keep you guys posted and thanks for the replys :y
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Hey guys
It was the top switch , its the low speed fan switch on the astra f/Kadett the bottom one is working fine since its the fan highspeed switch + ac cut-off switch.
Bridged it out since im still waiting for the new one , car is running better now .
Thank You :y