Saturday the Colorado Z Car Club (Denver area) had an autocross at a Sheriff's training center where there is a nice asphalt area...they even provided the cones for us!

I hadn't driven an autocross in about 22 years.  My 280ZX has fairly new all-season tires, as they were about the only thing I could find in the original size, but what the heck. I aired them up to 39 PSI all around and had at it.  

There weren't many cars there - about a dozen - so we all got in plenty of runs. I had about 8 runs.  It was a tight course, and I ran the whole thing in first gear, but that wasn't all bad because it kept the turbo spooled up so I had good acceleration power. Also good, my times dropped steadily.  I started off at 58:xx, then ran 57:xx. then 56:xx, then 54:xx, and my last couple of runs were 52:xx.  I managed to take off six seconds and didn't catch a single cone. The fastest time was set by a gent in a track-prepared 350Z  at about 44 seconds. 

It also gave me a chance to make sure the new helmet I bought for the autocross at the national Z Car Convention in Colorado Springs fit well.  I'm happy with it.

That was a great way to spend a Saturday AM, and the sun cooperated by hiding behind cloud cover until about noon. 

Edited July 26, 20213 yr by Pilgrim

I put a new battery and both cables in yesterday, (Close enough) But the old cables were shot and since the car and her cables are now 47 years old, a new set were ordered They need to be only 29 inches long, but now done it looks and starts up like lightening . . .

Driving it!

I have a "slight" starting problem, it fires right up, but idles low 500 to 600 RPM, and I went though my 1975 Datsun FSM and I believe the fault lies with the 'cold start valve' So being 75-85% sure of my diagnosis I plan on getting a fresh Cold Start Valve and see if I'm correct. If I have learned anything since my first introduction to the wide world of computers, as was taught by my elders, is 1. Only make one change at a time.   That way you know right away if it worked or not, and can be reversed if necessary. So we will see, but it runs P.E.R.F.E.C.T once up to full temperature and now with fresh oil and a good filter it is almost silent in operation. Which has it's own sense of satisfaction in it's own right !  😉

The cold start valve is not likely to be the problem.   It only operates for a very short time to assist with startup, then the thermotime switch shuts it off.

More than likely if the idle is low when cold, then improves and the rpm's come up once warmed up, you have a vacuum leak somewhere that is being sealed up after some heat gets in the engine and things expand.   An example would be the oil pan.

Actually (sorry) the auxiliary air regulator (AAR) is what keeps idle speed up until the engine warms up a bit.  Pretty common for them to be stuck open or closed and/or not have power to the heating element.  There are several threads on the forum about them.

  On 5/2/2022 at 12:13 AM, Zed Head said:

Actually (sorry) the auxiliary air regulator (AAR) is what keeps idle speed up until the engine warms up a bit.  Pretty common for them to be stuck open or closed and/or not have power to the heating element.  There are several threads on the forum about them.

Great help, I was wondering, if I have a vacuum leak, wouldn't the idle be increased not diminished ? Where is the Air regulator located and can I rebuild or clear the regulator ? Thank you,

Be careful unplugging it.  I'd check for power first.  It should have power when the engine is running.  Like the fuel pump.

Hi, If the engine is shut down, is there any chance of damaging it ?

Not sure what you mean.  You might want to start another thread specifically about your issue.  It might get lost here if other people start posting about their day.

A package arrived from France the other day.

French Jewelry!!!