Low rpm help

[Jaesx]

Rpms drop to about 300 400 rpm in neutral what do you guys think is wrong?

[S13_RB25]

It would help us a lot if you tell us more about the problem, and give us the car spec, then just rpms dropping down to 400rpms! Does it do it when coming to a stop or just when idling?? And also trying searching, cause most likely a problem similar to yours might've been on here already!

And welcome to nico

[Jaesx]

Haha sorry 92 coupe ka24de and it doesn't do it all the time mostly when comming to a stop. And the rpms float around from 300-700

[S13_RB25]

Well it could be couple of things! But start by checking your plugs, wires, rotor and cap! Oh also try cleaning your maf and use the search feature on here, lots of people have the same problem, but end up with different solutions!

[Jaesx]

I checked the maf clean as a whistle, everything seems to look fine theres a couple hoses im going to replace becuase they are dry rotted. I didnt really find too much information on this problem here in the search besides spark plug wires. Anyone else had this problem or know what could be causing it, maybe the iac valve?

[S13_RB25]

It actually can be that, try cleaning it! There's write up on here in the 240 tech articles, use that and you should be set!

[Jaesx]

Couldn't find anything on here any chance u could help locate it I'm limited to an iPhone takes forever

[S13_RB25]

iacv-aac-cleaning-and-testing-tutorial-t251133.html
There you go!

[Jaesx]

went to take the intake manifold off to get to the iac valve and found a big hole in a vac line im pretty sure that could cause the problem right? But i have all of the bolts and stuff off the top of the manifold i just cant get it to come off how the hell do you get this thing over the studs?

[S13_RB25]

went to take the intake manifold off to get to the iac valve and found a big hole in a vac line im pretty sure that could cause the problem right? But i have all of the bolts and stuff off the top of the manifold i just cant get it to come off how the hell do you get this thing over the studs?

Well why you trying to take the intake Mani off? You can get to the Iacv w/o taking off the Mani! Also replace that vacuum line with the hole in it, that is what usually causes symptoms like your describing!

[Jaesx]

I was going to clean it and paint it, but I got it far enough to see into it and it's clean. I still want to get it off to paint and replace the gaskets they don't look in the best shape and I also want to check the iac valve since I'm this far along. Any tips to get it off easier? I can get it to where I need 3/4 of an inch more on the top studs but that's about it, and it doesn't seem to be hitting anything.

[S13_RB25]

There are, IIRC 2 hoses underneath the intake mani, that you want to disconnect! Also did you take bottom half off already? Cause then you should be able to see the 2vacuum hoses im talking about.

[Jaesx]

So I need to take the bottom off first? How?

[S13_RB25]

Well there is bracket that runs from the bottom of the intake mani to the block, its held by 3 bolts! 2 on the block and 1 on the bottom intake mani! Also, IIRC, you have to take the bottom off first! Also get fsm, it'll help you with taking stuff off, putting it back on, and how to trouble shoot other problems!

[Jaesx]

I'm new to 240s I don't understand what you mean by fsm can you explain what it is and where I can get it?

[S13_RB25]

FSM is a factory service manual! I think if you search it in the 240 gen you'll be able to download it!

[Jaesx]

Finally got it all off now time to clean it out what can I use to clean the inside out I tried brake clean but it didn really do much anything I can soak it in or a stronger product to remove all the black grime

[S13_RB25]

Try throttle body cleaner!