1990 240sx with a KA24E idles at 1500-2000

[Jprosak23]

I just recently bought a 1990 240sx with a KA24E. When I bought the car I was notified that it had a bad fuel injector causing it to have a rough idle. I picked the car up and drove 2 hours back home. The day after picking it up I noticed that the throttle was getting stuck open and when I had my foot off the accelerator I was still gaining speed. When I start the car it idles at about 1500-2000, and the when I put it in drive it drops down and starts accelerating without me touching the gas pedal. After driving it around the block I put it in the driveway and put it in park. Once in park it goes back up and jumps between 2000-1500 when idling. I've tried to search everywhere and just need some advice. I already have cleaned the throttle body and checked to see if it was bent. There was a bunch of gunk and nasty stuff stuck in the throttle body. After cleaning it it didn't get stuck for a little while but now it's back to the same thing. Could the fuel injector be causing this or some other things I've seen are bad tps or vacuum leaks. If anyone could help that would be awesome

[Rogue One]

Welcome to NICOclub!

Sorry to hear that your car is having trouble. I've re-titled your post to get the best responses from those that know the most about your engine.

Unfortunately, I'm not all too well versed in your vehicle, but can offer an option for you. Here at NICO, we have Factory Service Manuals available free to members. Take a look at the link in my signature and you'll find the FSM for your car.

[centralcoaster33]

You could check the resistance of your fuel injectors with a volt meter tool. Stuck throttle could be the cable to your gas pedal, not just the throttle body.

[drewusmaximus]

Def sounds like the cable. Maybe the previous owner adjusted the cable too tight but, at the same time the cable is getting stuck? Can you take off the cable from the throttle body, start the car and see where the car idles at. Then rev the car manually with your hand to see if the throttle body goes back to normal or if it is getting stuck.

[Jprosak23]

I'm gunna try and see if the IACV needs to be adjusted first and then go for the cable. Thanks for the advise really appreciate it. The only reason I would think that it's not the cable is because the previous owner let it sit in the garage for about 4-6 months

[PapaSmurf2k3]

Vacuum leaks could definitely do that as well!

[Jprosak23]

Yeah I forgot to mention that I had changed all hoses that could have been a vaccum leak so that wasn't it

[drewusmaximus]

have you tried cleaning the intake section? Buy a bottle of Gummout engine treatment (white bottle that looks like the seafoam bottle), take a third of the bottle and pour it into a bowl. Start car, pull hose from brake booster that goes toward the intake, suck the solution slowly while car is running. Make sure the car doesn't shut off. so keep the trottle open to around 1500 RPMs so that the car doesn't shut off. Once the bowl is empty, plug the hose back in the booster, shut off car for 5 minutes. Turn car back on and rev between 1500 to 300RPMs until all the white smoke is gone from the exhaust. Then throw a half of a can of the engine treatment into the gas tank with at least a half tank of gas. Don't buy Seafoam because Seafoam is for two stroke motors. A lot of people don't realize that. That process should clear up the intake system i.e. EGR, IAC, etc..That might not resolve your initial problem but, it will clean out your intake and fuel system. Good luck!

[centralcoaster33]

All of the vacuum hoses? There are 5 hoses on the PCV that all have vacuum on them from the intake. I had the one from the PCV break and it caused significant problems. To replace all 5 hoses, I had to take the entire intake manifold off. Please see the photo of the PCV manifold and 4 of the 5 hoses (hose to PCV not shown in photo) here:
http://www.nicoclub.com/archives/intake ... embly.html
7th photo down, under "PCV System" title.
Hmmm, brake booster is also on vacuum... I figure you checked/ replaced that.

Also, you started off with mention of potential injector issues. Did you check the resistence? Were the numbers good? Here's how:
how-to-test-fuel-injector-resistance-t416697.html