zdude1967

Steve, It is a Japenese engine rebuilding company..The owner has a few Z'S and there were a few customer Z'S in the lot as well. Since the engine has only a few hours run time on it and is under warranty it is probably best for them to seek out the issues. I guess I am trying to determine if I should be as concerned as I am because I do not see the connection to no compression and the carbs. I am not Mr Good wrench but I do not see the carb connection. They said they checked the valves and they are fine, I would think the next moves would be either head gasket or rings. How does the Carb figure into this-if it does then I guess I must have confidence in there approach if it does not then maybe they do not know what they are doing. The number 5 and 6 spark plug seemed to have a much darker look then the #1 through 4 plugs. Everything has spark, the engine starts but runs very rough like it is missing and with the finger compression test # 5 does not push back on my finger at all which at first would, in my opinion seem to indicate a stuck valve however they said valves are fine and since the # 6 seems weaker then the #1 through 4 I am thinking head gasket. They said the plugs are not wet so it cannot be the rings, they also did not remember the compression test readings from the compression test they claimed to have performed. Not very happy at this point. What are your thoughts? Glenn

Hi, I just had my 260 engine rebuilt. It is running like s**T. I did a poor mans compression test (finger over the spark plugs while cranking engine) and the # 5 seemed to have no compression. In any case the engine is under warranty and the company that rebuilt it seems to be rather clueless. I say this because they want to check the carbs as they think this may be the issue. Now I do not claim to be Mr. Goodwrench but my understanding of this engine leeds me to believe that if there is no compression or very weak compression it would either be the valves or the rings. Would someone please let me know if there could be other reasons besides the rings or valves or if I am clueless with my ring/valve theory. By the way they claimed they checked the valves and that they are fine which is why they are moving to the carbs. Thanks Glenn

Thanks

Hi I just replazced the clutch preasureplate and bearing on my 1974 260z. It now grabs very close to the top on the clutch pedal travel. How can I adjust the pedal so the clutch grabs a little closer to the floor Thanks Glenn

Thanks everyone. I did time the oil pump and spindle. The reason I am questioning TDC is because it runs poorly. I did not do a final check to see if both cam lobes were off the valves therefore valves being closed prior to putting the valve cover back on when I did TDC. Thats why I am questioning it, the lobes were off the valves when I started however after some tweeking with a chopstick and the top of the piston I negected to make the final cam valve check and just closed it up. Anyway I am going to try the 180 degree out way of doing the plugs to see if it runs better, if so I guess I am 180 out if not I guess I can assume I am not. Does everyone agree that this should work

Would an engine run if the oil pump was timed to the top of the exhaust stroke instead of the compression stroke. I guess this is considered 180 degress out. In any case would it run and if it did how would it run. I set my oil pump but because the car is running poorly- kinda sputtering, I am second guessing if I got the top of the compression or the exhaust. Thanks Glenn

Thanks Gentlemen. I am off to the garage with some cold beverages and this information. Cheers Glenn

What does sunk mean, broken and filled with gas so they wont lift? please clarify Thnaks Glenn

By the way currently the choke cables are not hooked up. Would this matter at all, the jet should still move when the adjustment screw is turned. Correct? Thanks Glenn

I have a 260z with 3 screw carbs. It is running so rich that the fresh oil on a fresh rebuild is dirty and fuel smelling with only 2.5 hours of driveway idle time on it. Carbon fouled plugs, toxic exhaust. You get the picture. I spoke to Bruce the other day and was given some great hints. In any case I took the pistons out today to check the needle jet height and found that no matter which way you turn the mixture screw located under the carbs -all the way in either direction it seems my jet does not move. I have included some photos. I guess I am trying to understand what part of the jet is susposed to move. I assume it is the center bit, the part that is down about 3/16 below the bridge. Is this correct. Would I actually see visual movement of the jet if I crank the adjustment screw all the way in either direction. Thanks Glenn

Steve, Great thanks

I have a 1974 late model 260z. I am getting no power to the coil in any ignition position. I have replaced the ignition switch and lock. Needed a new lock anyway. I tested for continunity at the switch connector with the switch in the different positions Seems I have continunity. I checked the coil with a multi meter with the negative end grounded to the strut tower bolts and the positive on the coil positive, no power then I did the same for the negative side, no power. I did the same with the coil resistor at all connections...same thing no power there either. Where could I be losing power from the ignition switch to the coil.

I hooked a timing light and with with the dist lined with the timing mark at the adjustment nut the crank pulley timing mark is not even close to the timing degree tab. If I remove the dist nut and crank it as far as it will go towards the drivers side the timing mark gets closer to the crank pulley and timing tab but still a good 1/2 inch away from the entire degree measurement tab. Whats the deal. It also seems to idle way too high. All the carb idle throttle speed screws, balance screws etc are backed out to the point they are not even touching anything but the rpms are 1200 to 1300. It does lower when the dist adjustment screw is removed and the dist turned all the way towards the drivers side as far as it will go. At this point it also backfires through the carbs. My poor sick Z and my less then needed Mr Goodwrench skills are not seeing eye to eye. Any thoughts Thanks

Zed head, I believe this car has two fusable links. they seem to be OK. Here is another issue discovered yesterday. Steve perhaps you have some insight into this...The car is running poorly, I started it with the battery wired to the coil trick. I hooked a timing light and with with the dist lined with the timing mark at the adjustment nut the crank pulley timing mark is not even close to the timing degree tab. If I remove the dist nut and crank it as far as it will go towards the drivers side the timing mark gets closer to the crank pulley and timing tab but still a good 1/2 inch away from the entire degree measurement tab. Whats the deal. It also seems to idle way too high. All the carb idle throttle speed screws, balance screws etc are backed out to the point they are not even touching anything but the rpms are 1200 to 1300. It does lower when the dist adjustment screw is removed and the dist turned all the way towards the drivers side as far as it will go. At this point it also backfires through the carbs. My poor sick Z and my less then needed Mr Goodwrench skills are not seeing eye to eye. Any thoughts

1974 260z late model November production. Well I bought the new lock and switch and just received it. My lock was shot as the key could be removed in any position so I felt either way it would be a good idea to replace it. It has however not solved the problem as no power. I hooked a wire to the battery positive and connected it to the coil positive. The car has power this way and starts. It does run like crap but it starts. Since the switch is good wher do I go from here...my understanding is that the power goes from the ignition to the ignition transistor then to the coil and the dist. Is this correct. Thanks

I am trying to determine if my ignition switch is bad. Some history on the issue: I have a starter button which connects directly to the starter. The starter will engage without the key by pressing the button. It will however not start if the ignition switch is not in the on position. I believe this is because there is no electrical flow or spark. Currently I have no electric flow when the key is in the arse or ON position, ie no wipers, blower etc. Also no spark. I used a multi meter and tested all 5 wire connectors that hook to the ignition switch, I have power in one only it is the white /red wire. Is this correct or am I susposed to have power in all 5 wires. I have attached a photo for clarity. Could someone please help I am at the end of my patience.

I have some strange electrical issues and think it may be the ignation switch. Is there a way I can bypass the switch to check if the electric flows to the accessories such as blower motor, wipers, etc. Is there a way to make this happen. Thanks

Thanks to both of you. The red and yellow wires are post factory. It seems they hook a starter button up. They hook directly red to positive on the starter and yellow to the starter solenoid. I guess this is why I can get the starter to spin. Perhaps the other yellow wire I am questioning is the original yellow to the solenoid as it comes out of the engine harness and looks to be the right length to hook to the starter solenoid. Is it possible that since Motorsports does not sell the 260z ignition switch that the previous owner bypassed it and hooked up the starter button instead???? Again my electrical knowledge is very limited but from looking over the car, help from the both of you and the FSM I think this assumption is correct. This leads me to think the problem may be in not knowing where that second yellow wire goes...the wire leading from the engine harness and in the photos. I am thinking about either grounding this wire to the frame or trying to hook in it with the other post factory wire to the starter solenoid. .....your thoughts, suggestions etc. would be greatly appreciated.

I think it is on the wrong side fore that. It is coming out of the engine bay wiring harness, is yellow and slides over a small flat male attachment.

Car is a 1974 260z wire is on passenger side coming out the harness??? Photos should help someone who knows what they are doing....that person is not me!!!! Who knows where it goes Thanks Glenn

Thanks...such a bummer it is not starting.

Steve, Thanks, how do I find the grounds.The fusable link cover had water in it when I took the cover off. OUCH,even with no electrical knowledge that seems bad. I will pull the links dry them and check the connects. How many grounds are there and where are they. Thanks

I have a 1974 260z with a external starter button.Usually you turn the key to the on position and hit the button and it starts. If the key is not in the on position the car will turn over but not start. Seems the key being on ignites the spark and allows the electric to flow to the components. I just put the engine back in and when I put the key to start usually the electrical components become live. Usually at this time the defroster light come on if the defrost is on as well as the choke light or wipers if they are switched on. Now nothing no spark either. Anybody have any ideas as my electrical knowledge is zero.This starter button arrangement was in the car when I bought it so I have no idea how it is wired.,......Help

I need strut insulators for my late year 260z. Seems the proper item is very hard to find. Curtesy Nissan has a super imposed number for the original part that references to the same part as the 240z. This is about 3/4 of an inch lower then the original.Has anybody used this lower strut insulator on their late 260z or 280z. Did it make the rear droop. Is it very noticeable. How was the ride. Thanks ZDude1967

Jeff My carbs are 3 screw round domes. Are yours the same carbs and if so what height did you make the wood blocks Thanks Glenn