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1989 subaru legacy RS boost and ignition issues


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hey guys, my 89 RS is playing up on me for once :-/ when you flick the ignition all the dash lights come on as normal but when I turn the engine over the car starts perfectly but the lights still stay on.

 

ignition

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car on and fully running

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boost issues - as you drive along normally and not boosting car is perfectly fine. as i start to boost around 2.5k rpm it gets a tad jerky but then hits boost nicely but once you reach higher rpms the boost dies completely and feels like super VOD and doesnt pull and sometimes starts coughing. my idle is not too bad but sometimes when im warming the car down it will idle slightly higher around 1500rpm but will drop once again after a few mins. normal idle is around 1000rpm. how do i check that my icv is set correctly?

 

anyone know where these ecus are from?

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am i running the right ecu?

 

any help would be much appreciated :D

 

cheers

 

P.S it is a JDM legacy

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You likely have a ground short issue causing all the lights to stay on. All of the warning lights in the cluster are switched ground and none of them are common at any point except for right at the cluster.

 

Check over all of the vacuum and breather hoses under the hood. Any leaks will cause problems with boost pressure. If the boost is bleeding off competely it could be a mechanical problem with the waste gate, but with idle or stumbling issues a vacuum leak makes more sense. You want to be careful when driving with it like that, that boost needle can very quickly change direction and go way over before you know what's happening, then you get a hole in the block.

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The test circuit for the warning lights runs through the alternator field circuit. To verify that the trouble is within the alternator disconnect the connector on the back side of the alternator and then turn on the ignition to the RUN position. If things are ok with the wiring the warning lights should not turn on and it means the trouble is within the alternator. If the warning lights still turn on then there is a short to ground somewhere on the field lead of the rear connector to the alternator. I think the wire color is white/red or possibly white/black. The lead will have no voltage on it if there is a short to ground problem on the wire. Normally there would be about 12 volts on the lead when it is isolated from the alternator.

Edited by Cougar
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