Bad idle when using electrics.


Scottek

Scottek

Member
Joined
Sep 28, 2010
Messages
971
When i have my lights/heaters/wipers etc my idle lowers and starts to bounce a little. The needle on the rev counter doesn't move but you can hear it bogging down abit. The more things i have on the worse it is.

you can also feel the car bog abit whilst driving if i put my window down.

Someone suggested the alternator might be on its way out but id like some more opinions first.

any ideas?

Thanks.
 
bad earth is a possibility but more than likely the altenator. Have you checked the voltage its at when the cars running?
 
If you have aftermarket injectors and the battery table in ecu hasn't been modified to correctly compensate for system voltage drop under load conditions this can cause that. Check your earths first I guess and if they check out ok you may need to look at what I wrote above.
 
Earths are ok but i havent checked the voltage when running.

Ive got aftermarket injectors so ill look into the battery section on the ecu

cheers guys
 
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I've got the exact same problem in my EJ9 and its all completely standard, im pretty sure its the alternator. Possibly the belt needing tightening
 
I've had this problem when I was using a chipped OBD1 ECU but when i stuck standard one back in it stopped think it normally does rev a little lower if you whack the aircon on full straight away but almost instantly the engine comensates now and revs higher untill stable again
 
I would say it is most likley your alternator mate
EDIT*
Check it an average car charging system should usualy produce betwren 13.8 and 14.4 volts
:nice:
 
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Cheers for the help. I'm going to check over the battery tables in the ecu first and if that's all ok I'll look at changing the alternator.
 
Should be alternator had same problem in my old fiesta when under load it struggled
 
The ELD system is disconnected as when your car was tuned they use the ELD input for the wideband ;)

This is relevant to Hondata S300
 
I had the alternator belt changed today as it was very slack and worn but the problem is still there. (Didn't expect it to fix the problem but thought I'd do it first just incase)

The alternator was reading at 13.7 volts with nothing switched on. Then with the lights/heaters on it dropped to about 12. I've got a new alternator coming soon anyway but does that drop to 12 mean the alternator is buggered or is that just what happens?

If that's normal I guess it must be something to do with what vtec6000 was saying :(
 
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Have you checked the condition of the battery?
I would change that first?
 
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