KA20DE Performance

My friend has a 91' 240SX and lately we've been trying to hook up a custom cold air intake. We basically ran a tube down from the mass airflow sensor through the hole in the chassis, and then connected an air filter on the end. Only problem is that every time we try it, his car won't idle. It goes way low, then pops up to 1500, then back down....and won't idle steady. So do any of you know what we're doing wrong, or if there are any cold air intakes that he can buy? Also, what other suggestions would you guys make to go naturally aspirated? We were thinking underdrive pulley, intake manifold, and cold air intake....but we can't find any of these. Any help from you guys would be awesome. Thanks.

alright heres some info that may help a little:

first I'd say rebuild the engine, port and polish, low compression forged pistons, forged connecting rod, increase bore slightly for bigger pistons, forged or billet crank, titanium valves and retainers, valve springs, camshaft, cam gears, rods, gaskets, manifold, and throw a heat shield or two in if you'd like

then some other stuff:
in ( ) are some examples of companies that make that product

cold air intake(AEM, INJEN)
exhaust(A'PEXi, HKS)
downpipe
light weight pulleys(GReddy, ASP, Vernier)
header(Hotshot)
fuel pump(Walbro I think is one)
high flow fuel rail
larger injectors around like 650cc should work fine(Nismo, Denso)
iridium spark plugs and wires(Denso, Splitfire)

yea well I think you can handle anything more on your own, good luck and let us know how things go

Ah dang...thanks for the reply, but I guess I should have mentioned that he's only got about $1,000 to work with. That why we were thinking just a few things, like intake, manifold, pulley...

alright heres some info that may help a little:

first I'd say rebuild the engine, port and polish, low compression forged pistons, forged connecting rod, increase bore slightly for bigger pistons, forged or billet crank, titanium valves and retainers, valve springs, camshaft, cam gears, rods, gaskets, manifold, and throw a heat shield or two in if you'd like

then some other stuff:
in ( ) are some examples of companies that make that product

cold air intake(AEM, INJEN)
exhaust(A'PEXi, HKS)
downpipe
light weight pulleys(GReddy, ASP, Vernier)
header(Hotshot)
fuel pump(Walbro I think is one)
high flow fuel rail
larger injectors around like 650cc should work fine(Nismo, Denso)
iridium spark plugs and wires(Denso, Splitfire)

yea well I think you can handle anything more on your own, good luck and let us know how things go

u cant be serious can u? i remember when i used to install intakes on vw's there was a screw that u adjust and it opens the intake tube and as the car is on, u turn it with a long screwdriver and it changes its idle, until u find the sweet spot.. in no way will u have to do all that soyo just mentioned.

ok I wasn't saying he had to do that to fix the problem man, he asked for other N/A mods so I gave them not knowing he had 1000 bucks, but thats just a list of things you can go without turbo

u cant be serious can u? i remember when i used to install intakes on vw's there was a screw that u adjust and it opens the intake tube and as the car is on, u turn it with a long screwdriver and it changes its idle, until u find the sweet spot.. in no way will u have to do all that soyo just mentioned.

sometimes i wonder if you're running on all four cylinders :screwy:

What's a KA20DE? :uhoh:

What's a KA20DE? :uhoh:

hey isn't that the 200sx motor!? lol :loser: :rofl: :lol2:

i gotta hunch of what it could be. when installing a intake, i think you're supposed to reset the computer by taking the negative off the battery and let it stick for a minute then put it back on and start it up and then let it sit for another minute. if that doesn't work theres something else that's messing up the idol and its the sensor thats close to the throttle body. i got the same problem. i disconnected it and it was working perfectly. i don't know what that sensor is but if you know please share the wisdom

Violator, I'm sure soyo ment to say High compression pistons.

Get a thinner Head gasket to raise CR.
Port and polish is a low bang for the buck when early stages of N/a
I would go in this order
Cold air, headers, head gasket, 11:1 pistons, tune with more advanced timing.
but then you'd have to run high test

they actually have a KA20DE in japan, they use it in some mini-bus or van