Car has random loss of power

[z_ya]

the car is a 1978 280Z 5 speed manual and the issues are, most of the time i cant get it to rev above 3.5k rpm but then once in awhile i can get it to go till i let off but then right after that its back to the same old stuff at 3.5k rpm i have run out of ideas and would love any opinions on to why and how i can solve this problem. its not the afm or any of the electronics that i have tested through the efi bible so now the only things that i can think of are the timing chain is way out of line, the vacuum lines are hooked up wrong even though they appear to be hooked up fine but i cant find a vacuum diagram for my specific year either.... that or my distributor is angled off. any other thoughts and suggestions are welcome and will be greatly appreciated as it is killing me not having this thing running perfectly

[z_ya]

one thing i had not mentioned the car is running rich as well, i had sea foamed it but the problems are still there.

[Lazeum]

you're not specific enough about what you've already done to fix your issue.

I would get back to basic stuffs:

- do you have gas?

==> clogged filter, bad lines, dirt/rust in tank or in lines, bad fuel pump, bad fuel regulator, bad/dirty injectors?

- do you have spark? and when?

==> shape of your plugs, timing at idle & at 3000rpm, bad coil, good energy supply (alternator OK? good ground?)

Most of the item from the list could be checked easily.

then you can bother on more challenging items such as timing chain, valve adjustment, etc...

[z_ya]

sorry for the non specifics, what ive done since i first bought it is, re gapped the spark plugs and cleaned them, the injectors are good, the fuel line is good i recently replaced that and i do have gas as for the filter being clogged i will check that, the fuel pump is good so are the injectors and the fuel regulators the alternator is fine to. i posted because im new to z's and im just wanting more ideas and heads to help me on what could be causing the problem. everything appears to be in good shape except for this happening. the only things ive done are listed above and here cleaned and re gapped the spark plugs to the correct gap, replaced the fuel line and vacuum lines, then just recently we had run sea foam through the vacuum and the valves but not the gas tank.

[5thhorsemann]

How is the distributor advance working?

[Zed Head]

I tried to read Posts 1 and 4 but couldn't get through them before I ran out of breath and started to feel light-headed.

I got "the 1977 280Z 5 speed won't rev above 3500 RPM and has regapped spark plugs". Is there more?

[cbuczesk]

Take the plastic cover off the efi box and go for a drive. When you hit 3500rpm limit push on the big connector with your foot. Does that let it rev up? Sometimes I have to do that with my car. I haven't had time to really research it.

Chuck

[z_ya]

smackin the efi controller did nothing, i checked the fuel filter its fine, and yes i regapped the plugs to what my book had called for we have hooked the vacuum lines back to where they originally were so if they were hooked up right the first time then they still are correct, the firing order is right. like i said its burning gas and not making it above 3500rpm i floored it earlier and its like hitting a limiter it just stops dead right there. i know the book i have sucks mega arse but im thinking it might be my ignition coil can someone tell me what the correct voltage is for a direct replacement so i can try that.

[Zed Head]

www.xenons130.com/reference

The factory manuals don't suck.

[cbuczesk]

That's how my car is. It's like I hit a rev limiter at 4000. I know it's an electrical connection on mine since it usually clears up when I push on the big connector on the black box. You might want ot check all connections and grounds related to the efi system.

Chuck

[Wade Nelson]

Start by checking vacuum. That will tell you if the timing chain has jumped a link, if you have a valve spring that's broken, or other MECHANICAL causes for failure to rev.

Several sites on the web will give you a tutorial on how to use a vacuum gauge.

[z_ya]

no the factory manuals dont suck i said the book i have does, i have a cheaply made chilton with a haynes book on the way and i cant wait for it to arrive the chilton has nothing for my year and just shows random things that i dont have and then things i do have are not in there. We had checked the ignition coil today and it seemed weak thats why i was wondering if anyone knew the correct size of one that way i can go shop for one and order it to see if that fixes the problem while i wait for my haynes.