acfalconhawk

for the past few months my 89 240sx will idle straight at 1000rpm then drop to 500rpm and then climb to 1000 then back again repeatedly. after awhile it will idle straight at 1000. i can't figure out what it is. anyone have an idea?

revolutionz_s13

Mine does the same thing, I think it has something to do with the vacuum lines, but I'm too lazy to tear them all out and redo them.

2fast4y0u

could be a lot of things....some one correct me if im wrong
fuel filter, MAF, and vaccum lines. all possibilities of random idle.

wikd240

yup all of them are suspect here... start there and see how things go from there...

Fast1One

Try your fuel filter. 10 bucks problem solved. At least for me.

acfalconhawk

no, we just replaced the fuel filter a couple of weeks ago. this started in january.

Hyaline

fuel regulator?

drew935

clean the maf with some brakecleaner. Mine was doing the same thing for a lil while. Now it does something else. STUPID MAFS

revolutionz_s13

DO NOT CLEAN THE MAF WITH BRAKE CLEANER!!! It can ruin the sensor. To clean the MAFS, use carb cleaner. Much safer.

KAsingleC

lol, I staight up used acetone *iotch

drew935

thanks revolutionz_s13 for setting me straight on that. I'll do that tonight then..