Hi, I bought a 1983 280zx from a friend. It had been sitting at her house for at least 5 years. I replaced the fuel filter, fuel pump, put gas in it, and got it started. I've done a few things to it, new exhaust, changed the oil and air filter, swapped out the spark plugs, etc, but it seems to have developed this weird problem: the engine will just shut down...sometimes when i am at an intersection, sometimes when i am doing 50+mph. when it is going fast i can turn the key off and back on and the engine fires back up (it is an automatic). I replaced a lot of the relays (fuel pump, ignition, etc) and it is still doing it....before i take it to the car doctor, does anyone have any suggestions for what it might be? Thanks.

 

Welcome to ZDriver!

Does it stumble before shutting down? Or just at the snap of the fingers it's dead?

The main possible problems would be a bad ground, dying ignitor, or out of whack AFM.

 

the engine shuts down without a cough, or spit or anything, just disappears. Starts right back up usually. Notice it more when it is hot outside or when the vehicle warms up, but thusfar, it has always started back up.

 

Well... gotta check all the basics. Make sure all grounds and battery connections are tight and clean. Do the same for all sensor connections.

If it just drops dead and starts right back up, that sounds like a spark / efi wiring problem... Make sure the distributor is tight, check the ignitor on the side, and check the coil connections and mount to the strut tower. I had a 280zx n/a a few years ago that suddenly died on the freeway... pulled off to inspect, and the coil was literally dangling by it's wires.

One last question... when the motor shuts down, is there still power to all accessories?

 

Thanks again for taking the time to reply. I love these cars, however, i know very little about them. There is still full accessory power to everything. Interesting fact: it was about 20 degrees cooler today, and i drove it more than usual (about 30 miles), and it only shut down once.

I bought this car from a rich friend of mine for less than $200. She loved the car, and never drove it. It sat in her driveway for 3-5 years without being as much as started. It only has 90,000 actual miles on it. It will fly, even in its present state. i have just recently got it running, and have been driving it the last couple of months...

 

dont know if its been said yet but i had the same problem when i 1st got my Z. mass air flow sensor, and the little black box on the side of the distributor.

 

i second the TPS its on the side of the dizzy, my car had similar symptoms and i changed relays, checked AFM and gas pump and so on, turned out to be TPS hope this helps, check the basics first too like spark proper gas pressure so on so forth and clean your connectors but bet its the tps check that

 

Am I taking crazy pillzzz?

The 280zx doesn't even have have a MAF, it has an AFM. The 280zx does have a TPS (throttle position sensor) which is not on the side of the dizzy, it's on the throttle body.

I imagine you are both talking about the 2 prong ignitor that IS on the side of the dizzy?

 

like i said either AFM or the TPS i know what i mean
but i see where you might get me wrong i did mention on the dizzy i meant on the throttle body ;D
good looking out, nothing gets past you Nismopick ^.^
-.-

 

Just a note for those reading. The 280ZX TPS isn't a TPS like most vehicles. It's simply a switch that says that the throttle is opened or closed - not a Throttle POSITION Sensor like most other vehicles. That means the throttle can be opened 5% or 100% or any range in between and it doesn't differentiate. It's basically to tell the computer that the car is idling or not - not for load info...

 

Thanks everyone for the support of this novice....i checked all of the grounds, cleaned them and replaced them, and it still is stopping. Where to next, replacing the AFM? Also, the hose coming off of the AFM is cracked. There is a small crack that looks like an X. This wouldn't have any bearing on this situation would it? Again, thanks for the help.

 

Like they said check the afm there is a sticky for how to rebuild ur afm. Check the tps and the igniter on the distributor they are known for going bad a lot...

 

Well I guess I've got to do some trouble shooting myself. Right hand turns and my NA S130 shuts down briefly. Battery is tied down well and the grounds are good....

 

Thanks all. Bought TPS at Advance and i'm going to see if that is the issue. Rock Auto has a reconditioned AFM for about $80....is there any reason i shouldn't buy this instead of paying twice or three times as much for a new one?

 

well for starters... why not try this...
http://www.kamikazeracing.org/dl/JsAFMRebuild/
...its free thats at least one good reason if it doesn't work than buy the one for $80 always best to try to spend a little less the first time

 

Past experience with more than just the ZX, ignition module on the side of the dizzy. Had this happen with my '83 and with my HEI GM. The crack in the AFM boot is a bad thing. May not cause this problem, but bad none the less. My 2 cents, silicone inside and out on the boot, replace the ignition module and wait for the next problem. Five years sitting can be very, very hard on a car. With time and effort you will have one of the most enjoyable and reliable cars you can imagine. Sometimes it's a hard road to get there but paradise may be around the turn!

 

put the TPS module on, definite improvement in performance, but did not cure the shut off problems. I guess i will try to clean the AFM next...this is frustrating...