78 280Z Funky Fuel (EFI) Problems

[Neumeier]

Thanks for posting the FI manual! I downloaded it for future reference.

[m4xwellmurd3r]

haha no problem. I downloaded it to my car info folder to make sure i always have it (i have like 3 copies of it scattered on my PC)

[DatsunZsRule]

Do you notice a raw fuel smell when you do get it running??? You may have a minor fuel leak somewhere in the system which will also cause the symptoms your having due to loss in pressure not to mention very dangerous.

Also another possibility is a vacuum leak somewhere. I remember way back when I first bought my Z it sputtered so bad, I could see the entire car just shake when idling in my garage. My Z had both the issues I listed above plus a few other things It seems like theres always bugs you have to work out on a new classic Z purchase. Any car really. Part of the fun of the hobby

Good luck with it all and let us all know how everything turns out.

[The_Wondrous]

Do you notice a raw fuel smell when you do get it running??? You may have a minor fuel leak somewhere in the system which will also cause the symptoms your having due to loss in pressure not to mention very dangerous.

Also another possibility is a vacuum leak somewhere. I remember way back when I first bought my Z it sputtered so bad, I could see the entire car just shake when idling in my garage. My Z had both the issues I listed above plus a few other things It seems like theres always bugs you have to work out on a new classic Z purchase. Any car really. Part of the fun of the hobby

Good luck with it all and let us all know how everything turns out.

Well here's the odd thing. With a full tank of gas, the problems seem to go away and it runs fine. (We just changed all the spark plugs, fusible links, and re-wired a bunch of funkyness around the engine, and that didn't seem to help.) But once it goes about at a half tank it'll start actin up again. Now, there have been a time or two when my exhaust smelled like a gas station had just blown up behind me, but it normally smells fine.

I will check up on the vacuum leak though. Sometimes when my Z idles it'll be just fine at 1K RPM then drop down to around 800, (From what I've heard is the norm) and it'll shake really bad. Then on even rarer times it'll shake worse, sputter, turn over one last time then finally shut off. It'll restart right away, but the sooner I get this solved, the sooner it doesn't have to do that.

If my dad doesn't have the proper tools to check a vacuum leak we might just have to the dreaded thing and take it in. T_T But only for a diagnosis, I'm pretty sure if they tell us, "Hey, this, this and this are what's wrong..." It'll be no problem to fix ourselves. Paying mechanics is just too costly and not fun at all.

[DatsunZsRule]

That's correct. On a manual transmission model, 800 RPM's is where you want it to be @ idle.

Yeah, it wouldn't surprise me that you might have a vac. leak or small fuel leak somewhere. you can do a visual inspection too for any possible vac. leaks. some are pretty noticeable. On mine, both A.F.M. boots were split wide open. Pretty obvious For checking the fuel system, it's best to perform a pressure test to start. The 280Z is suppose to maintain 36.3 PSI.

Again, good luck with it.