Jump to content

Recommended Posts

Hi everyone, I have a 1971 240z with an L28 (N42) block and E88 head. The PO said it had been sitting for two years and it had a valve lash pop off due to sticky oil that I fixed. I also just redid the fuel system (newish 280z tank, new hoses, pump, filter. Carburetor float needles were stuck closed, but I soaked them in carb cleaner and they move freely now, cleaned the banjo fitting mesh filter. Also adjusted float level, timing and valve clearance as per FSM.


Here is a video of the car idling


Now to the problem. The car is idling very rough, engine is shaking, there is a loud clicking noise coming from somewhere and pulling spark plugs doesn't have much if any effect on the first 3 cylinders


So after switching plugs 3/4 and seeing a difference, I decided to try out all new plugs. I put them in, and #2-6 passed the plug test, while #1 failed. Pulled #1 plug and it looked like no fuel at all had gone near it, and there was a slow white smoke coming out of the plug hole (not steam).


Now after about 5 minutes of running, it seems the new plugs have started to foul again. Car is back to running like how it was with the old plugs.


Here is pictures of the old and new plugs (kind of erratic pattern of fouling on the new set)








Any thoughts?

Edited by kakapoopie
title change
Link to post
Share on other sites

tech - I have a stethoscope, didn't think to check the chain, thanks for the tip. And trust me I didn't want to buy those plugs, but they were the cheapest they had in stock.


Challenger - I think it is running rich..there is also a tiny pool of fuel that always gathers on the opening of the front carb. It's got a stock replacement mechanical pump

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...