Hi, I need help w/my 76 280z

It's been running rough when cold; have to give it more gas when cold to keep it running & it's a rough idle. It runs fine warm so I know I'm hunting down the right area, but am stumped as what to do next.

Last night I cleaned all the connections at the Thermostat housing including the Thermotime Switch, Water Temp Sensor & switch, and all bullet connections. I used electronic contact cleaner on every connection, and sanded all the bullet connectors & pins (best as possiable).

I understood that was the first thing to do, but I've done that & it is still running rough. I've read the maual & the efi bible. I know it could be either the:

Air Flow Regulator

Air temp sensor

Coolant Temp Sensor

Termo-Time Switch

and/ or the Cold Start Valve

The manual say to do continuity testing. I don't have a voltage meter & am really new to the mechnical side of cars.

Any suggestions before I start throwing new parts at it?

Thanks in advance for any help...

KCDC

Keith

I don't know if you have checked into it, but you can get a volt meter for around $10 (or less) at many stores and it is very useful to have around the garage for a variety of purposes. I am not familiar with Z car EFI, but I would recommend spending money on a tool (Voltage meter) before spending money by "throwing parts" at the problem. The tool will serve you now and in the future (and you will probably learn something from using it).

JMO,

$10 bucks, holly smokes that's nothing. I assumed (yea I know) that they would be MUCH more than that and then I would'nt know what the Shell to do with it; at $10 I think I'll take a stab at it.

I have the service manual, but it assumes the person reading it has electrical knowelge already, which I don't. I'll have to just jump in a learn.

The parts range from 20-100, so $10's a good avenue:)

Thanks for the heads up...

Doing a quick search, I found these :

http://www.harborfreight.com/cpi/ctaf/Category.taf?CategoryID=170&pricetype=

http://www.radioshack.com/category.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F008%5F002%5F000&Page=1&find=Multimeter(keyword)&hp=search

http://www.multimeterwarehouse.com/digitalmultimeter.htm

sblake01 knows quite a bit about Z Car EFI, so I am sure that he can chime in and help to advise you.

PS, I've attached a Multimeter operating manual. It is for a specific brand and model of meter, but I've found it helpful to me for learning how to perform some testing using my meter (of a different brand)

I have the service manual, but it assumes the person reading it has electrical knowelge already, which I don't.

I'm assuming you have the Datsun Factory Service Manual, as it has very detailed diagrams when troubleshooting the EFI. No such luck with Haynes, Chilton or Clymer.

Also, FWIW, there is a scanned version of the '76 Wiring Diagram to download at take to your local copy place and enlarge it up to trace the wiring easier.

76 Wiring Diagram 'Right Click and Save As'

Wayne

Thanks Carl; I've download the pdf and will read up.

Wal280z - holly smokes, can you actually understand/ work from that - You must be a wiz

sblake01 - I'm om'ing you in case this is a "oh yea, just do this.... is all you have to do" fix

Saw lots of threads on the carburated cold starts that looked pretty straight forward, but this efi system is complex!

I guess its time to learn some new skills...who knew getting your car to warm up could be so complicated...I guess I've just taken it for granted; until now...

KCDC

Keith

I pm'd you with a couple of suggestions. Does your car start right up when it's cold but you're not getting the 'fast idle' as it warms up? But is runs smoothly and normally once it's warmed up? My suggestions are based on that assumption. Let me know.

Thanks for the PM & offer of your expertise, If checking the Air Requlator is the fix, I'll post it here for others as well.

KCDC

Keith

sblake01,

The air flow requlator was partially open. I did clean it and check it's operation as well. Guess it good it's not that seeing how that cost $100.

Yes, the car does start OK, but run very rough until it warms up.

Any other ideas, checks???

Thanks in advance...

KCDC

keith