I own a 1990 Nissan 240SX 5 speed manual Trans. My Problem is this.....

Lets say I was to jump on the freeway, I shift to 3rd, 4th, or 5th gear, I floor my gas pedal and after i floor it for about 6 sec. (It has never does this to me while i am in 1st or 2nd), the power just cuts off for about 5-8 seconds. The engine is still running, but the RPMs are going down. It just behaves as if I took my foot off the gas pedal. But as soon as I kick the clutch in and out, right after it begins to lose RPMs, it overwrites its self and it begins to drive like normal.

What do you think is wrong.

Here are some details about my car.

The Tranny Raddles when i let go of the gas pedal in every gear except direct(4th gear)

After the engine warms up, my clutch makes my car shake when i slowly release the pedal.

The Speed Sensor works when it wants to.

The Speedometer gauge doesnt work and the car doesnt count miles(SWEET!)

The EGR system is faulty.

My check engine light turns on randomly.

you might have a compression leak somewhere. listen to your engine. listen for some whistling sounds.

Fight one problem at a time. I would start wiht the trans as it sounds the most messed up.

Get the trans and clutch working right so you can make the most of the power you have.

What codes do you get from the ECU when it is displayin a check engine light?

Have you cleaned the MAF?

Done a General Tune-up Latly?

Does the "cut out" happen at the same RPM all the time?

Make sure all of your trans sensors are plugged into the trans. Almost sounds like your hitting the gear limiter in 3/4/5 gear

I have checked all that.

I diagnosed the ECU manualy, it tells me that my Speed sensor is faulty and my EGR valve is faulty as well.

I cleaned my Air flow sensor and and the input connection.

Its still doing it.

Im doing a leak down and compression test next saturday, maybe thats the problem.

Wires have just been nicely cleaned and tight on the sensors, but still doing it.

This is a shot in the dark but I had a similar problem recently. Remove the AIV hose running back into your intake. Go buy a little cone filter to put on the black box where the hose was. I got a 90 ka24e (autotragic) and was experiencing the same symptoms as you describe only it lasted for about 3-5 seconds. It only did it when I was cruising on the freeway at around 65-70 mph. Whenever I would give it gas to speed up, it would stall. Since removing that hose, I've yet to experience the issue again. Now it runs good as H-E double Hockey Sticks!!!!

Hope this helps
Modified by cbt240sx at 7:46 PM 6/4/2008

Thanx! Yes, it was that, and something else, actually 3 things. I got about 20 pages of OEM Specs. Checked everything and 12 hours later.......

-Timing was off-Thottle Position Sensor was WAY-Off!- Air Flow Meter was really dirty because the EGR (the Little Black Box on the right hand side. Right before the air filter, was broken from the bottom part) was wrong and contaminated the Air Flow Sensor.

Thanks for all the Advise!!!

Sorry to bump an old thread buti just swapped a ka24e into my s12 and it does the exact same thing. Im only pulling ecu codes 14 and 41. I'm not sure what you are talking about when you say aiv hose.. My egr and vacuum system is mostly deleted. Any extra info or words of wisdom would be much appreciated