i recently bought a 92 2+2 300zx 5 speed and i love it to death. Whenever i'm exiting off the freeway after being on it for over a coupe minutes the engine shuts off. I'll be going like 80 then put the car into neutral and then coast until i exit. In the middle of that coating is when the car turns off. I look at the rpm and it starts jumping right under 1000 and right above 0 until it eventually shuts off. I avoid this by down shifting every time i exit. If i down shift down until 3rd gear and then go to neutral the engine is fine. I have a feeling it has something to do with the drive train but that's just a guess. Can anybody shed some light on how to fix this problem? Thanks

Ricky

 

it's happened to me before and i can't put my finger on what fixed it. it seems a good tune up would fix it up well. i have to go to class now, i'll say more later.

 

Do you have a pop charger?

 

If you are coasting in neutral, I don't think it's the drive train.
Is this only after being on the car hard, and then coasting?
I.E., getting the engine nice and hot, and then trying to idle?
Idle will be lower on a manual car than an auto to begin with.
Will it do it with the A/C on?
If you turn your A/C on while at idle and parked, will the car bump the idle speed up regularly?

Could be numerous problems.
Could be fuel pressure from an old filter or pump. Injector spray pattern from dirty injectors, or something like IAC that is not able to compensate. Even a good vacuum leak can cause a problem.

Any more answers you can give us on the specifics would be cool. Like the engine temp, actual rpm range when it dies, wether you are coasting in gear with the clutch engaged, etc.

Could even be timing that is slightly off. Does the car idle well warm and cold, and at the same RPM?

 

Does it do it right after you rev up? Like the needle goes straight down into a stall? If so I 'd check your vacuum lines for leaks (or in my case a rag in the throttle body) but yeah sounds like when you leave a vacuum line off.

 

I missed reading about the rag....
You car was on the rag? hahahahahahahahaha!

 

Basically

What happened was I bought it from some kid who couldn't get it through emissions/safety. I don't have emissions testing up here so I bought it and fixed the safety problems. The car ran ok but I figured it justed needed to be tuned. I thought the timing was off or something.

Then one day after a long drive the throttle got stuck open. Pulled the left intake off and found a rag jammed up into the throttle body. The painter two or three owners ago put it in when he was painting the engine bay and then put the intake on over it.

When I pulled the rag out and buttoned her up she ran, obviously, like half the engine wasn't there before. While it did cause some sudden stalls when I drove hard (or as hard as I could with half a motor) I doubt it's the problem in this thread.

 

... I guess the thread started didn't want an answer...

 

Or maybe he found a rag?

 

thanks guys. Now i know what to look for. The engine turns off when the rpm is at 3000 or over for a constant period of time and then i hold the clutch in while i coast. I think the quick transition from high rpm to idle while coasting shuts it off. Thanks for your help again.

 

You didn't answer my question... DO YOU HAVE A POP CHARGER?

If you do, install it properly and your problem will go away. Turbulent air is causing your MAF to get a bad reading and your car to die. Installing the pop charger with the splash shield where it's supposed to go will remedy this issue. Search... I've provided a diagram for installing it before (in the "Performance/Technical" subforum).

 

It sounds like a dodgy MAF to me. 3000rpm seems to be the point at which it kicks out.

Check your MAF or its sensor. One way of checking is after it cuts out, pull in, remove the sensor connection and turn the ignition. If it starts straight away and was giving problems before doing it, its telling you what it is.

 

im still with zlover its a VERY common problem with the pop charger many people neglect. and also the most likely culprit. time to open the nose section and take a peak