280Z fuel

Did this happen all of a sudden? And yes if you open the AF meter and it runs better it's lean. You really do need to measure the fual pressure and check and/or replace the temp sensor. If those don't show anything, might be easier to just loosen the spring in the meter and see how it runs?

I'm measuring about 40 lbs when it cranks and about 30 when it is running on the fuel pressure. I have not finished measuring everything. If all else fails I may have to do something like you suggested. Its been running bad for something less than a year. I think its getting worse. It took a suuden jump for the worse last summer.

greg

Let me add some notes, but I have not reasembled things. I decided to take the flow valve off and check it in detail. Strange thing, I still don't know the circuit exactly. Making resistance measurments is really interesting, but the only way to check it is to power it. In making resistance measurments I was able to smooth down fluctuations . They don't necessarily show up powered up. I smoothed down the carbon trace and flattened the contacts somewhat. I used cleaner and some Caig moving contact stuff. If I assume the analog computer is working correctly and all the sensors, the other thing I might check is the flowvalve bypass. I didn't try adjusting it lately. Perhaps I can get it working tomorrow.

I did check out the flow valve. It does have a spring tension adjustment. I don't want to change it without first measuring the current torque.

I did also check the rubber between the flow valve and the throttle body. It is often the problem if any leaks are there.

greg

As a follow up, I report things are much better. I loosened the spring, probably less than a half turn, adjusted the bypass mixture. I may have a problem with the cold start valve, but it runs pretty good warmed up. I now feel that surge of power. Feels good.

greg

We do that with them all the time. I stopped worrying about why they need this done long ago. If it fixes the car and it runs good, that's all that matters!

Thanks. Just one thing that has always puzzled me, my 77 Ca. car edition seemed to have a slightly different spec on fuel economy vs 49 state. Never could figure out why that was. Only the Ca. had a convetor, which I emtied long ago. I'm not sure if my car has a vacuum advance either. It seemed to me there was no hose, but I'll check again.

greg