zclocks

Yes, I should know better. I've seen so many corroded connectors on clocks that I just replace every wire /connector. The thing that fooled me is that the connectors didn't look bad, but corrosion is resistance. Thanks again for the input. Ron

Dave you are correct there are 2 transistors in the control unit that are associated with the pulse to the injectors (FSM EF-51).One transistor is associated to injectors 1-2-3 and the other with injectors 4-5-6. I did this check with the 3 volt lamp as indicated in the manual and both transistors check out. This isn't an exact performance evaluation , but rather an overall output check. Funny I remember many years ago I had a lamp that was provided with a FI meter I purchased and no explanation of what it was for. I don't know what happened to it, but that was the lamp as mentioned in the manual. I also pulled the dropping resistors and cleaned everything including the connector contacts on both sides. All the resistors measured 6.5 ohms. After I reinstalled I checked that the power relay was working and there was battery voltage at the control unit pins for each injector. The car is running MUCH better and no backfire thru AFM. The drop outs are farther apart and very small compared to previously. I went back and retested with my Colortune unit and the visual blue flame is much better on cylinders 1,2,3. There are still some drop out or miss fires, but not as many. The intensity of the Colortune flame is much brighter. Cylinders 4,5,6 are unchanged, bright in color intensity and no drop outs. So, I think part of the problem may have been with the connectors on the dropping resistors or the control unit connector. What I am going to do is remove and clean all connections on the distributor, transistor ignition unit, and injectors. All my injector connectors were replaced about a year ago and I still have to replace the AFM connector. It looks good but the boot has deteriorated. I would like to dig into the transistor ignition unit and see what's going on there. I need to hunt down an OEM unit for testing. Anyone have a spare they would like to part with? I still believe there is a slight problem, but I think I'm on the right path. Thanks for all the inputs it's really helped. Ron

I haven't swapped injectors, not my favorite thing , but that's just about all that's left. My car use to idle very smooth and had quick throttle response. I know there's a definite miss in 1-2-3. Could be the injectors not working correctly although they sound good . What are the chances that just 1-2-3 injectors are bad? Ok, thanks for the input and I will proceed with my quest. Ron

Thanks Mark. I'll take a look at all 3 again. Yes, the plugs are BP6ES, NGK plug wires and Nissan cap / rotor.

I have not driven the car . The problem is the miss at idle and I know it will be a problem when I do get it on the road. It should have a smooth idle. Problem is the miss in 3 cylinders.

Ok, I am officially stumped on this one and need some help. Car 75 Calif 280z with only 80 miles on a rebuild 14 yeas ago. I know it's along story . Problem: 1-I have a small back fire thru the AFM only some times when I crack the throttle. 2- cylinders 1,2,3 have a small drop out(loss of spark). 4,5,6 look very good using Colortune. What was checked: 1. Originally the car would not start. Fuel pump was bad and replaced. Idle pressure 32psi and pump head pressure is 40. 2. Checked pressure regulator and not leaking at vacuum port. 3. Plugs replaced as they looked very dark. 4. Vacuum is 17mmhg and steady. 5. AFM boot cracked and was replaced. 6. Adjusted valves (cold and hot). 7. Checked timing , 10 deg btdc 8. Air/fuel meter indicates I am now running slightly lean (at operating temp) and rich at start up. 9. Checked timing chain mark on cam shaft sprocket . Is just to left on mark #2 10. Cap and rotor inspected and no cracks or discoloration. 11. checked resistance of plug wires and all within 500ohms. 12. checked all 6 dropping resistors. All measured 6.5 ohms Observations: 1. I have a shut off valve on the fuel line and can isolate pump pressure from fuel rail. The gauge is after the shut off so I can check pressure between the gauge and injectors. I might have one or several injectors leaking as the pressure drops off in about 30 min. 2. Using Color tune plugs 1,2,3 have a weak spark , some misses in spark and are slightly blue(good color) 3. Plugs 4,5,6 have a bright spark, consistent firing and no misses. So what it looks like is that plugs 1,2,3 have a weak spark which could be causing my backfire. The only common point I see between the plugs would be the dropping resistors, which all measure the same 6.5 ohms, spark plug wires, coil, and distributor. At this point what am I missing? Any help would be appreciated. Ron

Sorry I didn't see this thread earlier, but through I would throw in a little more knowledge about AFM meters. The air flow meter is a very very sensitive instrument and has several known weakness. One of which is the temperature sensor. If this drifts the signal sent to the Control Unit will change which in turn will change the air fuel mix. And create a cascade of changes/problems. Second the substrate, called thick film ,has resistors that will drift over time. The resistors are ruthenium dioxide (look and act like glass )when centered or fired at high temperature. The exact resistor value is trimmed with plunge cuts into the ruthenium via a laser and the value desired monitored by an ohm meter. This all sounds good, but the problem comes with time when cracks develop at the end of the laser cuts. In essence the cracks grow and the resistor changes value. This can be minimized if the substrate with resistors are cured and the resistor values rechecked. This costs big $ for commercial products so they eliminate this step. In addition, the white substrate is alumina (aluminum oxide), very brittle and prone to cracking if not attached to a very rigid surface. One word of warning NEVER REMOVE the screws from the substrate. You will crack it. My 75 OEM AFM has a thick film substrate made by BUORNS and the one currently in my car is made by OHMIC?? So we have resistors and temperature sensors that change over time, gas which is been reformulated, and different manufactures of the resistor substrates . My original AFM in my 75 would intermittently quit working and at the time and I had no idea what was in the AFM. I was told that it, the AMF, was bad so it was replace. What I discovered was that the air temp sensor was slightly out of speck. The resistor substrate is just fine. This OEM AFM always caused my engine to run rich as well as the current AMF I have on my car. What I believe is the gas has changed in CA and the AFM as adjusted for the 70-80 vintage gas is the problem. For many years I have had to adjust my AFM to the leaner side to get through smog testing. Nothing has changed in my AFM , but the gas has changed. As I discovered recently the boot between the AFM and the TB must be air tight. I struggled for days tuning a new motor only to find I had several small cracks in this boot. Once the cracks were sealed what a difference. Ok one more thing to pass forward . The engine water temp sensor next to the AFM air temp sensor are the two most important parts of the FI Control Unit inputs. If either of these two items drift or change it throws everything off. The change I speak of is a slow drift out of specification. Particular attention to their performance is key. Well this is my 2 cents worth and I hope it helps someone trying to learn about the FI process. Also check out the enclosure. Ron

Jim, I just noticed that you have a 75z also. I'm close to Orange county so if you find a good shop please give me a shout. I hope to be getting my car back on the road before summers over. Ron

Yea, I have only ever had one shop in Century City that knew how to adjust the camber without crating problems. The shop is long since out of business , but it would be nice to have a shop that really knows Z cars. I have been visiting several "Alignment " shops in my area and they will not be touching my car! Ron

Suggestions for wheel alignment shops on SO Ca? Looking for one that caters to 240/280 Datsuns. Thanks ..Ron

Ok I corrected it. Thanks again....Ron

Thanks Zed. I was toooo lazy to flip the photo.. Actually, to make the corner I cut the seal at a 45 degree angle and glued it in place with shoe goo! Ron

I finally figured out how to fix my door seal problem and thought I would pass on what I found. My problem was that my passenger door seal works perfectly , but my driver side you had to use both hands to shut the door . These seals were put on years ago and should have taken a set by now . From my research and talking to several rubber suppliers I was shocked to find that many Z car owners are experiencing the same problem I have. I looked at the fender alignment, hinge alignment, and door panel trying to discover what the heck was the wrong. Most of the door on the driver side sealed correctly , but from the door sill to the top of the door on the latch side was really interfering with the door . What had happened was the rubber seal was bunching up between the door and the body. The normal gap for the seal was 1/4 inch when compressed , but my door seal was 1/2 inch when compressed. See photos of what I'm talking about . The seal should have been designed to normally push down under the door . Instead the seal I had was normally facing up and being compressed between the door/panel and the seal attach point. This could have been just this seal or a seal that was from a different supplier. What I was told was that there are only 2 rubber suppliers that make door seals for Zcars. I can't verify this but who knows. I couldn't find the Aki door seal as mentioned in the previous text and if ordered it would cost over $100. So looking on Amazon I found a wealth of door seal possibilities. The seal I ordered from Amazon is near perfect , seals the door to the body, and looks good. I think time will tell if the seal takes a set and remains sealed. One thing I did find was that a seal should only be compressed 25% of its original diameter to make a good seal. Any more than that and the seal will deform / compress and not seal properly. One other piece of note worthy advice is those who have a Zcar shop do ANY work for you should make 2 appearances per week at the shop unannounced to check the progress on your car. I trusted the guy that owned the shop I used and have regretted it to this day. I can't believe one shop could make the number errors that were made on my car if they tried that hard. This was only one the 47 other problems I have had to correct. And this was a shop chosen by Nissan for the vintage Zcar rebuild program. Hope this helps someone who is having the same problem. Ron

Thanks for the input . I will investigate and let you know what I find. Ron

Does anyone have a good supplier for 280z door seals. The one I need is the one that crimps on body around the door opening. I've heard Kia Sportage is very close to the OEM Datsun seal, but don't know the year of sportage. Thanks...Ron

View Advert 280z mechanical clock For sale is a nice 280z mechanical clock . This clock was working when I received it and has been keeping decent time for the last month. The plating on the housing is very good, I polish the lens, and re-blacked the set knob/mounting bracket. The clock number plate is for a 75/76 280z , but I will change it for a 77/78 280z. Actually the only difference between the years was the number plate. Price is $145 + shipping. Thanks for looking Ron Advertiser zclocks Date 04/12/2019 Price $145.00 Category Parts for Sale

Hey guys I translated the FLXW to English. Gives all the nits of the wire , but not the amperage. Enjoy....Ron

Good info., but does anyone know what the amp rating is on the black and green wire? Thanks .....Ron

View Advert Refurbished 240z clock mechanism Refurbished 240z OEM clock mechanism. The mechanism was completely disassembled, cleaned , and inspected. Worn parts were replace and the clock was reassembled and tested for at least one week. You will have to make 2 solder connections, remove 3 nuts, and install your clock hands on the mechanism. Price is $100 plus shipping Thanks for looking and please PM me if you have any questions. Ron Advertiser zclocks Date 03/31/2019 Price $100.00 Category Parts for Sale

View Advert Wanted Quartz clock(s) Wanted : Quartz clock(s) as attached in photos. 280zx analog quartz 79-83 and 280z quarts 77-78 offering $55 . Please PM me. Thanks....Ron Advertiser zclocks Date 03/31/2019 Price $55.00 Category Parts Wanted Year 79 Model 280z

View Advert 280z clock circuit board FS is a rebuilt clock circuit board for an OEM 75-78 280Z. NOTE: this is not for a quartz clock The caps and transistor have been replaced and the board tested for one week. NO core required . Cost: $55 +shipping Thanks for looking, Ron Advertiser zclocks Date 03/28/2019 Price $55.00 Category Parts for Sale