View Full Version : My sr surges at idle when I turn on elec. components
bluezenkis14
11-29-2011, 08:46 AM
First off I tried to search it but my I phone won't let me for some odd reason
Anyway...
I have an s14sr with electric fans and hid headlights the car idles fine when nothing is on but as soon as the electric fan kicks on the idle dropps and It goes really rich and when I continue to put the headlights and/or rear defogger it's almost/does stall I basically have to keep it revving to keep it running I can't find the problem I checked my alternator and battery... Also checked vacuum and boost leaks nothing came up I also have noticed that the alternator clip has two wires connected to it and one wire hanging close by to it off the harness but when I searched that up all the clips had two wires coming off it... I don't know what to do any suggestions/known fixes would be much appreciated thank you
badbob2121
11-29-2011, 09:22 AM
honestly sounds like a bad alternator, but i assume you mean you had it tested when you say you "checked it"...
bluezenkis14
11-29-2011, 09:26 AM
Yes I tested the alternator and battery Im really not sure what the alternator is supposed to put out voltage wise but the battery read 14.1 volts so I assumed the alternator was good
DJDANGER24
11-29-2011, 09:30 AM
Like badbob said, it sounds like your alternator cant hang with all the extra amps being drawn. You could have 14.1 volts all day, but if your alternator isn't pumping out enough amps under load, then you will continuously have a huge drop in idle like you do. How exactly did you check your alternator? You just checked the voltage reading on your battery while it was on?
bluezenkis14
11-29-2011, 09:34 AM
I also tested the alternator but couldn't get a reading on amps but got a good reading on volts
bluezenkis14
11-29-2011, 09:51 AM
I'm going to change the alternator I know the ka alternator fits... Is there any difference in output? And can I buy an alternator for a ka at like car quest or something of the sort?
silver350z05rb
11-29-2011, 11:59 AM
my alernator 2 wire clip was loose once and car idled like shit and wanted to shut off after it warmed up, noticed cluster was dimmed, went to go check the ground, ground was good, the clip was not in all the way, there was something blocking it inside so i wouldnt feel or hear the "snap" the clip makes when you plug it into the alternator.removed the debris and it finally clicked in
bluezenkis14
11-29-2011, 12:06 PM
I will look at the wires also after I get out of work today
Croustibat
12-01-2011, 05:25 AM
The ECU compensate voltage drop on neutral by revving the engine. If it does not, that is either because it cant act (check your idle actuator is working and you have no leak), or because it does not detect it (gearbox neutral switch not working, or wires cut).
You can check if the neutral switch is working quite easily, it goes to the ECU, check the pin (i dont have the SR20 ECU pinout but you can find it quite easily) .
It could also be a faulty alternator problem though.
cbcm2435
12-01-2011, 07:13 AM
probably alternator, i think you can take it to autozone and they can test it to see how many amps its putting out
bluezenkis14
12-01-2011, 08:22 AM
The ECU compensate voltage drop on neutral by revving the engine. If it does not, that is either because it cant act (check your idle actuator is working and you have no leak), or because it does not detect it (gearbox neutral switch not working, or wires cut).
You can check if the neutral switch is working quite easily, it goes to the ECU, check the pin (i dont have the SR20 ECU pinout but you can find it quite easily) .
It could also be a faulty alternator problem though.
By actuator you mean the iac? And where is the neutral switch? This is on the the 5 speed trans?
bluezenkis14
12-01-2011, 09:31 AM
ECU Pinouts - Nissan 240SX Forums (http://www.240sxforums.com/forums/sr20de-det/118010-ecu-pinouts.html)
Here is the Pinout I have a couple of lose wires which I'm almost positive that this will solve my problem but time hasn't been on my side lately so I havnt been able to really tackle this I know a green wire is cut on my harness on this Pinout it says the green wire is the scitx out. Any word on what that is?
bluezenkis14
12-01-2011, 10:49 AM
Just checked the harness all the pins actually checked out only thing I found was wires were branched off to what seemed like they went to some modual that was possibly previously on the car like an safc so im pretty sure it's not the harness
Croustibat
12-01-2011, 10:53 AM
i dont know what it is. TX stands for transmission, so this might be part of the OBD2 system, but that is just a guess.
I also dont know what your ecu is :p
pin 35 on the first 2 pinouts are the neutral switch. Not green though. The switch is on the 5spd manual yes. There are 2 position sensors on it, one near the rear, the other in the middle. One is the rear drive switch, the other is the neutral one.
bluezenkis14
12-01-2011, 10:58 AM
I have the s14 ecu I will check when I get home if that pin even exists on my particular harness for the previous owner did some bad hack job to all the wiring and I've been fixing it ever since(2 years ago)
bluezenkis14
12-01-2011, 11:02 AM
pin 35 on the first 2 pinouts are the neutral switch. Not green though. The switch is on the 5spd manual yes.
On the s14 ecu it is pin 44
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