Fuel air ratio help?!

[Danbo]

I have a 86 nissan d21 z24 2.4L rwd
It is running rich and was wondering if anyone knew what the correct fuel air ratio is supposed to be for my truck? And if the screw is turned all the way IN, How many turns out would it be to set it right?

[Static808]

I would say play with it lol n tune it to.how u like it

[Longtooth]

If your going for emissions you need a sniffer so you can adjust as needed. My weber on my zuki I back out till it runs like shit then turn back in till it runs good.

[SkinnyG]

When I had carbs, I'd adjust to the highest idle vacuum.

This might not pass emissions - to pass, I'd lean it until it just about stumbles (but not lean missfire - that would increase HC).

[smith]

[XoXSciFiGuy]

The big general problem with those type of engines they made back then is that not even Nissan engineers figured anyone would still be driving them almost forty years later.

What often happens is all the stuff they added to those engines to make them pass US emissions...eventually starts complaining or wearing out...

And the aftermarket parts manufacturers still aren't offering brand new throttle body systems with all new parts included...

So eventually you either have to wing it as best you can...or keep it tuned with the best parts and adjust stuff occasionally. Just not TOO much playing around or they will run worse than before.

The other option is to do the Weber carb conversion, but then you may not pass emissions in your state (if it has emissions) and your mileage will drop anyway.

Trust me. Been down this road many times. MANY times. I had a few of these trucks back when they were new or newer. (I will attach a picture of one I owned from 95-98. When I had this truck, it went like a bat out of frickin' hell and did the zoom zoom for sure.

But it was only nine years old when I got it, and with low miles, and back when dinosaurs still roamed the earth. When these trucks started hitting America they were a beautiful thing. And they still are. But...if some aftermarket company started offering brand new TBI systems, COMPLETE ones, they would make a killing from classic Nissan truck owners. People would flood them with orders, rip out their 40 year old TBI systems, and install new ones. So far....nothing. It is a real hole in the parts market these days. You can damn near build yourself a 65 Mustang through the aftermarket. But classic Nissan has always been shorted by the aftermarket companies. Like Rodney Dangerfield, we just get no respect.

I'm not always right, (ask other members lol) but I have been working on and driving classic Nissans since about 1978. I've had the 70 Datsun truck, the 78 610 sedan (way ahead of its time), a couple of B-210's, (dangerous on curves, too light in the ass end) a big 810 with the six cylinder fuel injection, and even an 82 more recently that I restored and sold. (Picture below)

Been there. Definitely done that. They should bury me in a Datsun lol.



The ZX from 2018, taken before the restoration while it sat at the previous owner's house:

[cadillacdude1975]

My EGR deleted carbed VG33 pathfinder passed the tailpipe sniff test. They finally canned the emissions testing here. A local senator got the law changed. It was deemed a tax on the poor.

[street_rulerr]

back it out 2.5 turns. 900 degrees. thats a standard place to start.