Hello everyone, I am new to the forums here at zdriver.com (great site and I have found a lot of info as I browsed and searched). I have not found an answer or hint to my specific issue though...

My '92 300zx non-turbo cuts out when it's above 40mph. If I engage the clutch the rpm's drop instantly and the engine dies, same if I just engage it long enough to take it out of gear and put it in neutral. As long as the car is moving above 40mph is the only time it dies. It remains running perfectly at any lower speed and I am completely puzzled.

I have cleaned ever contact I can find and I am not getting any fault codes or errors.

Any help on this is greatly appreciated.

Thanks,

 

does this mean that you can't shift at all above 40 or is it just going into nuetral? can you start the car with the clutch out?

 

I can start it in neutral or in any gear with the clutch engaged.

I can shift above 40 and at any speed. The engine however only cuts out when I am moving faster than 40. So if I am changing from 2nd to 3rd at 30, nothing happens, but if I go from 3rd to 4th (or any other gear) while going faster than 40 the engine will cut out if I don't shift fast enough. Also happens if I go into neutral completely. Thanks for the questions, its really bizarre and two different dealers and two different shops haven't been able to figure it out.

 

i feel like ive heard this problem asked before. cant remember what was said. i wanna say something with the MAF of some wierd air intake problem causeing a wierd MAF reading.... its so vague in my memory, try searching those terms in the Z32 section.

 

there is a switch that stops the car from starting when the clutch isn't in. mine has been disabled by a previous owner, maybe it might help you to do the same. that way, the computer won't even know when the clutch goes in. or maybe the problem is that this switch is bad. this is just a possibility. good luck

 

that switch does nothing other than to tell the car that clutch is engaged so that the car can be started.

 

http://www.twinturbo.net/ttnetfaq/FAQpages/stall.html

 

correct. but how else does the car know that the clutch is in? his problem is only occuring with the clutch in. if it can idle sitting still and up to 40mph, it just doesn't seem like an engine problem to me. just my thoughts. possibly worth a try.

 

haha ^^^ the stalling isnt because the car "knows" the clutch is in, its because there is no more load through the drivetrain. Zlover poster what i was talking about, im so surprised i remembered it.... in a way

 

No, Willkrom is right.....how else would the computer know when to engage and dis-engage the electric clutch?

 

lol, totally. wilkrom, all that is is an inhibitor switch, aka it just induces a ground i believe which is a fail safe in the starting system only. with out it, the car wont have the ground to properly engage the starter selenoid. aight! why do you think you can push start a manual car

 

if it was the clutch switch, he would have problems every time he pushed the clutch pedal in.

 

Stop making sense.

 

ok ok. got it. i'm a little stuck in the train of thought required for a british car. no computers

 

I'm going to continue beating this dead horse.....Your statement still makes no sense....the computer has less then nothing to do with this. I friend of mine drove an '82 Ford Pinto. The neutral safety switch went out and I'm pretty sure that car didn't have a computer. If it did, then it was no more advanced than an E.T. Speak & Spell. Just admit that you have no idea what you're talking about here so that we can move on.

 

youve been pretty malign lately. why so?

 

I'm pretty sure Speak & Spell was manufactured by Texas Instruments and not E.T.

lol i know you were just referring to the movie in which the Speak & Spell was most prominently featured.

now back on topic.
I'm going to go out on a limb here and say it's a fuel probelm.
FPR, Fuel Dampner or fuel pump, check'em all, but my money is on the pump.

 

^ Try this. Make sure all of the oem plastic shields are in place. The problem is most likely caused by turbulent air going thru the MAF. You need a smooth flow of air.

This should also be helpful:

http://s95014253.onlinehome.us/63104/80397.html

 

yea that just happened. two posts ago.. thats why wou were "continuing" to beat a dead horse. not conected to the computer. understood.

 

and i had stopped. i wasn't stopping you from "moving on".

 

I had a similer issue with my N/A 93 a few years back. It would idel fine but if there was wind moving past teh front it would want to stall, it was REALLY bad in a car wash with those blowers...it would stall every time the dry cycl would start.

Turned out to be a 3 inch long vacuum hose with a worn spot on it. Had the replaced, bam, no more issues ever.

 

This part f*cking disturbs me...

 

Ditto. How can you take your Z through a Car Wash... You don't know how long it's been since some Lazy hick in a mud covered pickup decided to run his rust-bucket through the auto-wash to get the old mud off... Do you really think those brushes are clean? They scratch the $hit out of paint/clear coat. Take the time to wash it by hand... or at the VERY least in the 'do-it-yourself' bays...(just remember to spray the brush first)

 

i dont even use the brush. just a spray wash, and sometimes an absorber

 

I don't even wash it!

hahah i'm kidding, but i don't think you need to be that extreme, most likely your paint has other flaws that would make freaking over it not worth it. If it is, then I guess it works for you