Nissan engine trouble. KA24E (Long sorry)

[Malibu]

Hello, First off id like to thank you all for this wonderful forum. Ive been searching for a good nissan group that will help me with my car troubles. Finally here it is!

I have a 91 Nissan Stanza that has practically the same engine as a 240sx (KA24DE). I bought it 3 years ago and it has 120k on it. Its been a great car up until about a year ago when the transmission failed. I had that repaired drove it for about 4 months trouble free. I bought a 4x4 truck for work and decided to park the Nissan for While for the winter season. I would occasionaly go outside and start it to make sure everything was ok. The gas tank had about a half tank it and I added some Stabil gas treatment to it to keep the gas in working order.. Everything was fine. When spring time rolled in I decided to put it back on the road and thats when I discovered an Engine problem.

The engine would start fine. And Idle roughly. I tried to rev up the RPM's but as soon as I gave it gas it would want to choke right out. I Imediatly let off the gas and it went right back to idle. I experimented for a bit and noticed that if I baby the gas very lightly add pressure to the gas pedal it would eventually rev up. I tried to put it into gear (Automatic Trannsmission) and it died right away. Basically the engine apparently cannot handle any load.

I started troubleshooting.. I checked the simple things first. All the fuses were fine. Air filter was acceptable. Took a close look at all wires/connectors everything seemed to be fine, no corrosion seemed to be present. I then went to the local parts store and bought a fuel filter, air filter, PCV valve, spark plugs, O2 sensor, wires, Dist cap/rotar. After installing all those i became confident and started her up. Problem was still there. I then started asking local garages about it and they seemed puzzled like I was. Many suggested to check the fuel pump, MAF, and Cat/converter. I tried the key in the "On" position and noticed the fuel pump primed fine. Since the garage had told me to test it that way and if it works in a prime cycle then it would be fine under normal operation I figured it was fine and didnt want to go further with it if that wasent the problem. I then got desperate and had a hunch that the cat converter was plugged so i removed it. I could see light on the other end of it.. it seemed to be firm with no loose parts inside. I reinstalled it. I removed my MAF and brought it to a Nissan dealer and they tested it (Free of charge) and said it was fine.

Since after all this and it doesnt act right I gave up on it and parked it. This all still bugs me very much and ive been reasearching on the internet quite alot latley and came across this web page. I found the FAQ topic

http://www.240sx.org/faq/articles/carstalling.htm

very helpful and it gave me some insight as to what may be the problem. Although I did try gas cap trick, and that didnt work. This page mentioned something about a "Coldstart valve" I would appreciate if someone could elaberate on this some please and give me a hand. =]

Thanks, Malibu

[Mayhem_J30]

bump

[drjohn]

That model is a KA24E single overhead cam eng. The cold air regulator is used to add air to the mixture when cold and is more likely what they are talking about. It sounds as if the throttle position sensor connection is corrodided or the sensor is bad. This tells the ecm the throttle position and adjusts the mixture to what the eng. needs.