greylandimports

God damn it. The gas is bad. I was rereading the post and someone suggested it before. Draining it now. Thank you for the great tips!!!! Does this make sense to everyone else??? I think its my big problem. Now how do I go about flushing the system?

Also, I was reading other posts on here and I was putting a lot of fuel through the carbs. I turned the knobs under the carbs two full turns out. Could this cause a problem?? On only three cylinders??

Well, I got a compression tester in the mail and my compression is good. When I hook up the timing light, the light doesn't flash on the cylinders that are not firing. I know that 2,3,5 are not firing. When I pull the plugs on these cylinders nothing happens to the idle of the engine but when if I pull 1,4,6 the engine dies. The plugs on 2,3,5 are wet when I pull them, and 1,4,6 are dry. There is some black discharge leaking out of the plug holes too but I think I didnt have them tight enough. I made sure all the plugs had good connections and I put the plugged in spark plug next to a body ground and it sparked. What else can I check?

This Z really knows how to kick me when I'm down!!!!!!! I opened up the two knobs under the carbs and it ran rich but it was running real smooth! When I reved it up it still wouldnt go above 3000 RPMs so I bought a timing light and a week later when it came in the mail I went down to set the timing. When I started the car it was only running on three cylinders!!! I checked all the connections, pulled all the plugs, cleaned everything up.. but no luck. The spark plugs are sparking and they are wet with fuel when I pulled them out. What could have happened? The cylinders that are NOT working are 2,3,5. I bought a compression tester online and I'm waiting for it to come in. I really hope the problem isnt loss of compression. The motor was rebuilt not even 1500 miles ago (about). The reason we rebuilt it in the first place was that it was only running on three cylinders.. so I'm not hopeful. How could this have happened? Could running the car out of timing and carbs out of tune do this??? I don't have the experience to rebuild the motor. I did it five years ago with a mechanic and I don't think I can do it by myself. Any ideas?? :'(

Hello Gents! My first day back in the garage from a long winter and i had a lot of success! I went to a junk yard and found the spacer and adjustment plate underneath the distributor from a 280z. I put those on and reread my manual on carb tuning. I figured out one of the things i was doing wrong was adjusting the throttle speed screws while they were almost all the way screwed in. I saw in the manual that it says to unscrew them for a lower idle (among many other things). Now i have my idle at a little under 1000 rpms! Now to the problem... I have been messing with all the adjustment screws and nobs and here is where I'm at. The idle sounds semi-smooth but when I rev up the engine the car 'tops out' at 3000 rpms. It starts to break up real bad and does not rev much higher. I'm trying to adjust the distributor to find the sweet spot but I'm having no luck. My assumption is that the timing is off because it idles at low speeds o.k. but at higher rpms where the timing becomes more critical- it cant do it. Am I correct? Or might I have the air/fuel mixtures off in the carbs and that's causing the problem? -Thanks guys!

Hello Gents! My first day back in the garage from a long winter and i had a lot of success! I went to a junk yard and found the spacer and adjustment plate underneath the distributor from a 280z. I put those on and reread my manual on carb tuning. I figured out one of the things i was doing wrong was adjusting the throttle speed screws while they were almost all the way screwed in. I saw in the manual that it says to unscrew them for a lower idle (among many other things). Now i have my idle at a little under 1000 rpms! Now to the problem... I have been messing with all the adjustment screws and nobs and here is where I'm at. The idle sounds semi-smooth but when I rev up the engine the car 'tops out' at 3000 rpms. It starts to break up real bad and does not rev much higher. I'm trying to adjust the distributor to find the sweet spot but I'm having no luck. My assumption is that the timing is off because it idles at low speeds o.k. but at higher rpms where the timing becomes more critical- it cant do it. Am I correct? Or might I have the air/fuel mixtures off in the carbs and that's causing the problem? -Thanks guys!

Hey Gents! Its getting warmer and I'm back in the garage! I just wanted to say thanks again for the posts! I hit up a junk yard and found a 280z spacer and adjustment plate that I lost and now I'm trying to get it to sputter after a long cold winter! I replaced the distributor with an electronic one; replaced the spark plug wires, and the dist. cap. I'm sure I'll have some more questions soon! Wish me luck and thanks again!

Well then I must search for such for such a thing! I'm on the hunt for good carb tuning instructions! Can anyone suggest something for a first-timer??

Wow! What a great site! Thank you for all your suggestions I was previously in Vermont and haven't found the time to respond. I cant believe I forgot to mention that I had put in an electronic distributor instead of the stock. Maybe this makes a difference? I think I'm going to start over from the beginning. I was kind of teaching myself how to set the ignition timing as I went... even though I did it and redid it several times, I might have gotten something wrong. It has been a while since I did it and now I have some more things to conciser.. I have another question. In my z car manual it writes about how to begin to tune the carbs by setting them back to their original settings. However these directions are not very clear. Does anyone know of any other publications that have directions more easily followed? Thanks gentlemen!! -Graham P.S. Other bits of information that might be of value: I put a performance cam shaft in, and one of the biggest problems is that I had the car running pretty well, with almost zero backfiring, but I couldn't get the idle down below 1000 without it running really poorly.

I am in desperate need of helps and suggestions! I have a 1971 240Z that I cant get to run correctly. I will try to be as detailed as possible in explaining my dilemma. I would like to preempt your responses with sincere gratitude as I have about given up in my attempts to solve this problem. I go to college in WV and don't have the money to cover the mechanic bill to fix my poor z car. Specs: 1971 240z, rebuilt straight six, one wire alternator Tools at my disposal: Every hand tool imaginable, a timing light, a carb sync tool First, I bought my z with four working cylinders so I, along with the mechanic that worked there, rebuilt the straight six. After we were finished, the engine ran very rough, so I drove it over to my favorite mechanic who tuned carbs with only a screwdriver in about two minuets flat. I drove the z pretty often for a couple years after that before heading off to college. After totaling my other car, I decided to drive my z to college. I drove it an hour and a half there and back several times until it broke down on me. I then towed it back home. It took me a couple months to figure out the problem. In these couple months, me and my father had turned and returned every screw on the carbs so much that by the time I figured out that the problem was that the stupid bolt underneath the distributor had turned a half an inch, it was way too late. Now, I could only get my z to run for a very few rough seconds before it died. I then abandoned the z again after failed attempts to retune the carbs and headed back to college. Now, onto my senior year, I decided to tow the z back to college and try to fix it in-between studies. I missed it I bought a Datsun repair manual and did my research. Through fine Datsun form sights such as this one, I was starting to make progress. I first bought a carb sync tool. I synced my carbs and played with balance screws and adjusted nuts through the directions of my manual. I also experimented with the distributor. First, I took it apart in order to better understand the part and ended up cracking the coil inside it. After a brand new distributor from auto zone I was back in business. I looked up how to get the timing from the manual and the internet. I found top dead center and set up the timing as best as i could. I made great progress and actually got it sounding half decent for the first time in years. After attempts of fine tuning I actually ended up making it very much worse. Then, realizing adjusting the carbs wouldn't make any difference unless the car was timed correctly, I bought a timing light. This is where I am currently stuck. As I look at the timing light, I am about four or five inches away from the mark! How is this possible?! As I turn the distributor closer to the mark, the car dies. Clearly something I did was wrong. If I can't get the car close any timing marks, how can I even begin to tune this motor? I am at a complete loss and need help! I don't know very much about motors, as I am just a body man. I learned some when I helped to rebuild the motor and from the internet and manuals but that's it. I have always been a do it yourselfer and refuse to bring it into a shop. Thank you all very much for your help. It is very much appreciated!