[i_like_d_z]

After testing just about everything imaginable in my fuel injection system and cleaning every connection I could find and finding nothing out of spec. I remembered something that seemed a little strange when I tested the air flow meter.

As I pushed the flap on the AFM the ohms readings had a set pattern. It would jump from a set number (I think it was like 3 ohms or something) and then down to 0 and then back up to the 3 again as I continued to push it in. It does this about 5 times until the AFM is fully open.

I thought that the resistance was supposed to get progressively greater as the angle of the AFM flap changed. Is it supposed to jump up and down like that? I'll bet it is sending incorrect readings.

Thanks

 

[johnb510]

Yep, the reading should be smooth. If it is erratic, jumping around, going to zero, ect... it is bad.

 

[slavkos]

radio shack control claner.cotton swabgently clean wiper or what wiper runs on. do this only before you decide to buy a new one much sensitive but wth.you may be able to lift the wiper enough to clean it.carefully. sam

 

[TurboSi]

Precisely what I finally found wrong with my '81ZXT after months of diagnostic checking. I did what Slavkos did (only using lacquer thinner instead of electrical cleaner) cleaning the rheostat part over which the pointer under the AFM cover moves. I did not try to "lift" the delicate pointer, but instead cleaned around it as I moved the flap which moves the pointer. Then, I gingerly bent the pointer arm down so that it provides a bit more pressure on the rheostat part. This manuever was even recommended by former Datsun mechanic to me, with the advice that it was not unusual for this to be done at the dealership when that problem came up. Anyway, Voila!!! Car ran great - no more lean this time and rich next time erratic behavior. Has been running great for 2,000 miles now.

 

[i_like_d_z]

Thank you all for the great advise. I'll keep you posted.