Engine stumbles when electric fan kicks on

[marcrx5]

I'm working on my 240sx, trying to get it drivable, and I hooked up my electric fans, flex-a-lite dual fans. The car idles fairly smoothly, but when the fan kicks on, it will start to stumble and die. I tried grounding it in another place, and it does the same thing. There is a sr20det in the car. Is my fan causing a draw on the engine, and if so, what can I do to fix this. Thanks.

[myshtern]

Check all your belts

Maybe alternator?

[HONDA GHANDI]

Its probably a large electric load that the ECU cannot see and is not bumping the idle up for. See if there is any way to crank up your base idle a bit to compensate.

[myshtern]

Do Nissan ECUs have problems with that?

[Weston]

Electric fans don't have belts. It sounds like what Tobi said... the electronic load detector (if it has one) is probably not working correctly. The fan kicking on will change the idle for a second, but it's not supposed to stumble.

[myshtern]

Electric fans don't have belts. It sounds like what Tobi said... the electronic load detector (if it has one) is probably not working correctly. The fan kicking on will change the idle for a second, but it's not supposed to stumble.
I read it wrong

Do really old subaru's have the same "mechanism"?
I've been working on some old subaru and we got it to start but something starts sucking all the juice out of the battery after it idles for like 2 minutes. I was thinking it was some sort of fan or whatnot.

[marcrx5]

Thanks for the help, but I think I figured it out. I tried adjusting the idle higher, and it worked better, but still seemed like to rough of an idle when the fan was on. I decided to work on some other things that needed to be done instead. Before, all I had was the turbo inlet connected to maf, with no filter or anything. Obviously I wouldn't want to drive around with out a filter, so I made a ghetto pipe with what I had, connected it between the maf and turbo, and put on the filter. I started it up to see how it ran, make sure there were no leaks after the maf, and to my amazement, when the fan kicked on, nothing happened to the engine. I think my problem was the turbulent air messing with my maf sensor readings. Either that, or the maf never had a good connection in the first place, and when I reconnected it, I connected it better. What do you think? I'm just happy it works better now.

[HONDA GHANDI]

Maybe the fans were cramming hot air from the radiator into the MAF freaking it out. Either way, good job on the fix.