9/73-E31-260z Posted December 4, 2013 Share Posted December 4, 2013 (edited) So I have an L24 (P30 block/E31 head), stock as far as I know. Last week when I got the car back from a shop to redo wiring the car ran fine, I babied it around when I drove it a few times since it hadn't been driven in 4-5 years, kept it below 3,000 rpm the whole time. Sunday night it wouldn't start but I figured it was just too cold and the battery had started to run down from cranking the starter so many times (didn't burn it out, starter is fine). When I got the car it didn't have the air filter on it, so I did drive it without it (for less than a day, less than an hour total drive time). I cut some bolts for it and put it on today and gave it a jump to start, started up fine but wouldn't idle. i can get it to start fine on its own even but it just won't idle. I changed all the spark plugs just before I gave it the jump, and I put brand new NGK plugs on it last week. When it wouldn't I checked the new plugs and they seemed almost identical to the old ones. I popped the distributor to check it out, and the points have some white corrosion on the, and the rotor is a little dirty but doesn't seem to be corroded. I am thinking this is the problem, and I actually have another dizzy from a 280zx that I want to put in anyway. Does this seem like that is the problem? I included pictures of the plugs and both distributors. The plugs are 1-6 left to right. Also the L24 dizzy is the first set of pictures with the 280zx in the ones after that. Edited December 4, 2013 by 9/73-E31-260z Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted December 4, 2013 Author Share Posted December 4, 2013 Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 5, 2013 Share Posted December 5, 2013 Those aren't points. The proper term would be electrodes or contacts. You have electronic ignition already, the ZX won't be any better unless you have a bad ignition module. Since the engine runs, that's not very likely. Seems more like a carburetor problem. Did you leave the choke on? You should describe what carburetors you have for the carb people. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted December 5, 2013 Author Share Posted December 5, 2013 (edited) I don't have the ZX distributor in it yet, sorry if I didn't make that clear. So I do have the points type distributor on there now. And I have early 3-screw SUs, I'm assuming they were rebuilt since I found a receipt and the instructions for a rebuild kit from MSA in the car when I bought it. They seem to be working well, but the only real difference between last week when it ran fine (albeit in need of a slight tune) and today after I put the air filter on. Here is the cap from the ZX distributor I have, seems clean but I was also concerned about the rotor in the pictures above^ is that ok, too far gone, or can I clean it? Edited December 5, 2013 by 9/73-E31-260z Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted December 6, 2013 Author Share Posted December 6, 2013 So I was tinkering a bit more today, and my neighbor came over to help (guess he had a 260 2+2 back in the day). I was able to get it to idle by adjusting the idle screw but unless it was set to about 900rpm or higher it would die after about a minute of running choppy. He lent me a compression tester but I probably won't be able to get numbers til late next week. I'll post as soon as I test it. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted December 9, 2013 Author Share Posted December 9, 2013 Soooo I feel like an idiot... I misunderstood the writeups I have saved for tuning carbs and what I thought were the mixture screws are actually the individual throttle screws Car is idling fine now, no thanks to me messing with those screws back and forth. Still a little rich but I'm going to sit down and tune them later this week. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted February 21, 2014 Author Share Posted February 21, 2014 (edited) So I tuned up the SU's as per Scott Fisher's procedure. The engine seems like it's running better but it still seems to be misfiring a little. This is a short video I took just after a cold start, sounds like cam lope almost but it's not really supposed to sound quite like that right? This is after driving about 15 miles, sounds "warmed up" but it still has that lopey quality to it. It doesn't seem to stutter or hesitate except at around 1500-1800 rpm, and even then only barely, everything else seems alright. My distributor is pretty worn and might need a new rotor, would replacing the rotor and cleaning the points clean up the idle? Also I have to set the idle at 800-1000 rpm at least otherwise it really feels like it's gonna stumble and die, I couldn't find much info on what the stock L24 idle speed was, is it supposed to be that high? Other L series I've seen have been below that. Edited February 21, 2014 by 9/73-E31-260z Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 21, 2014 Share Posted February 21, 2014 would replacing the rotor and cleaning the points clean up the idle? Post a picture of the points to show what shape they're in. Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted February 21, 2014 Author Share Posted February 21, 2014 Not sure if have a picture but they're pretty frosty white Quote Link to comment Share on other sites More sharing options...
9/73-E31-260z Posted February 21, 2014 Author Share Posted February 21, 2014 I've tried to scrape the deposits off but couldn't really make much progress, is there a certain method I should use to worry about damaging anything or can I just use some fine grit sand paper? Also I have a complete 280zx distributor, could I maybe use just the cap from that? Or is it not compatible? Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 22, 2014 Share Posted February 22, 2014 You're not getting the point. By now you should realize that what you're calling points aren't points. My efforts have been pointless. Those six frosty things in your picture are not points. If you want to learn a little automotive history, get on Google Images and type in "ignition points". Then look at pictures. It's the conductive paths to ground or other electrodes from dirt and arcing that cause problems in the cap. Best to get a new one. Quote Link to comment Share on other sites More sharing options...
madkaw Posted February 22, 2014 Share Posted February 22, 2014 :rolleyesg :rolleyesg Quote Link to comment Share on other sites More sharing options...
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