ckurtz2

As per google: Issue- "an important topic or problem for debate or discussion". Don't let politics win. Issue is what it means, not whatever politics says it is these days (if that's what you are referring to as liberal jargon). Problem or issue could be used synonymously here. In hopes that you actually cotribute to the conversation. I will change the title. @Zed Head Thank you. I am going to run through the FSM on Wednesday for EFI and see if anything new comes up. It seems hard to test electrical as most of the FSM wants you to use an oscilloscope, which I don't have. Really don't want to shotgun buy parts on this one. Also let me know if the duplicate post was removed on your end. I think I was able to get rid of it.

Hey Guys, I hate having to post in the fuel injection section of this forum, because I hate EFI issues, but here we go. I will try to be as detailed as possible. As you know I have had some EFI issues in the past, but I got them all sorted out about a month or two ago and my car was running near perfect. In the past two weeks I have been having an issue where the car will either surge at idle, buck hard under part throttle or hit essentially a rev limiter. Happens damn near randomly, except it has definetly been getting worse over the past few days to the point where it is undriveable as of this morning. I first noticed it about two weeks ago in Arizona traffic in the hottest part of the afternoon. Out of nowhere the idle fell from about 1200rpm(yes Ik its high, I have since resolved this issue) to about 300 then it caught itself and went back to about 1500, and then just did this repeatedly. And then it just randomly stopped and I was good to go. Next time I noticed it, I experienced the same thing. I was idling at a car show in line for a long while and poof idle randomly fell. When it falls it's extremely abrupt like my fuel pressure goes to 0 or spark is cut entirely, then it would catch itself and shoot way past my set idle speed and then fall again, and then randomly smooth out. After this happening for a few minutes I was able to leave the car show and I WOT onto the highway entrence and about the biggest cloud of smoke came out the tailpipe that I have ever seen (grey). Then about ten miles later on the highway the car would loose all power under any throttle input for about 2 seconds (RPM on tach stays the same) and then catch itself and be fine. Next time I noticed it was a few days later. Started the car, it warmed up and immidiately it sounded weird. Gave it a rev and it popped big out the intake, AKA super lean. Ok, turned off car, started it again and the problem immidietly dissapeared. The next day I started it cold and it started rythmically popping out the exhaust, big booms out the back under part throttle. So now it was being super rich. Restarted the car and the problem went away again. Now in the past week when I drive it around the block (trying to figure out when the problem is occuring) it will surge at idle only sometimes(rarely now) but under part throttle it either bucks like all hell or hits what seems to be a rev limiter. So as you can see it's been a little impossible to diagnose as symptoms change almost what seems like daily. The car bucks like hell warm or cold now. It also struggles free revving. The tank is rust free, new spark plugs, new injectors, new fuel filter, etc etc. I watched the fuel pressure at idle and its a steady 28psi, under throttle it raises as it should. So I am at a complete loss if this is a spark problem or fuel problem. Luckily the the problem was consistent enough today I could pull out my phone and snag some videos. You can see that the car bucks badly, and hits a rev limiter. All of this was recorded at the same throttle input (1/4 throttle or less). I got it to rev up without cutting when I matted the pedal. As you can see it's like riding a bull. https://urldefense.com/v3/__https://youtu.be/12XZ2cdfsO0__;!!IKRxdwAv5BmarQ!fE9nrDYKDsfg3pQMI3nISyNOzjJOgfXGtS6ZOtQ11qQhDp_XGhAh6wzW5KRg0tbBiD28vwXgz6ChP2MZ1ASj2SoX$ https://urldefense.com/v3/__https://youtu.be/AhmiXD09NwM__;!!IKRxdwAv5BmarQ!cbEdNrHLCcm69RgNO5EzHkIZL9xu_zTAcNqN4yUP8151vyGAxeI0EW-ffHhFaQ7WDQLLbCZJ_xSxxEU3Y_GstqcP$ Is this a typical issue of a failing ECM or Trignition Module? Out of all the forums I have read I can't get a lock on if it is.

That is awesome to see how the unit is actually supposed to function. Thank you for taking the time to do that. Mine definetly wasn't working like that. Mine must be defective, good thing I am returning it. Anyways, I ended up just cutting the wire at the C1 connector and routing a new one. Gauge works good as new. Another thought I had is possibly the wire tracker device was working. And somehow my sending unit wire shorted with other wires and caused the signal to go crazy. Worries me. However, every gauge works, headlights work. I'm not sure how to confirm this as I was never able to locate where the wire went bad.

Interesting. No, my harness is 100% stock with no alterations. Let me know if you figure it out. So far I think I am just going to return it. I tested with a multimeter at both sides of the C1 connector and it is continuous, so I am feeling really safe now that somehow the wire went bad inside of the engine bay. I think I am just going to cut the wire at the connector and solder on a new one and run it all the way up to the sending unit. Probably not going to touch the wiring harness itself, I'll just ziptie or electrical tape it to the harness at different sections. Kinda sucks the harness will now look altered, but in reality the car will probably be completely rewired in the future when I have it undergo a full resto.

Well I am at a loss. Got a wire tracker from harbor freight. https://www.harborfreight.com/cable-tracker-94181.html Used it for the better part of an hour and a half, but got no where closer to finding my issue. I connected it to the end of the wire at the sending unit and then grounded it ( I tried grounding it to the chassis, battery, manifold, block, etc). Anyways, it worked in the sense that It gave a tone at the wire. More than two feet down the wire though the tone would dissapear no matter what. In addition, I'd get a tone when scanning the manifold, fuel injectors, fuseable links, car chassis, roof of the car. It was incredibly frustrating. The tone would dissapear before I could reach the C1 connector when I had the tracker hooked up to the wire at the gauge. The tone would also dissapear before even reaching the interior when having it hooked up to the oil pressure sender wire in the engine bay. The oil pressure gauge works, so I know the wire is fine. Not sure what to do here.

No I understood. I actually snipped the harness about 6 inches before the bullet connector and then aligator clipped it directly to ground to try and eliminate this issue of possible corrosion. Didn't work. In addition, I deoxed and wiggled around the C1 connector (it already looked pretty shiny inside before). So I am feeling pretty comfortable the wire is severed somewhere in the harness. That tool though will be a great help.

@SteveJThank you so much for the pointer, I didn't know such a tool existed. That makes life 100% easier. Hopefully I'll only have to remove part of the harness wire and not the full length. Anyways, I am confident it is not the bullet connector, and that it is somewhere in between.

Ok, so I grounded the yellow wire at the C1 junction on the diagram. That connector ended up being in the passenger side junction box. Anyways when I grounded it the gauge shot to 250 again, so I now know the interior side of the harness is good. So now the problem must be between Connector C1 and the bullet connector. It is one continous wire in this section. I am still at a loss how the wire went bad. Anyways, I am wondering how I should go about replacing this wire. Should I cut open the protective wrapping around the harness and then remove this one wire. This would be unfortunate, because this yellow wire travels down the passenger side of the car, then through the front of the car next to the headliht scoop, across the front of the car in front of the radiator, through the driver side, and then all the way back to the manifold, then over to the sending unit. Should I cut the wire at the C1 connector and then add a bullet connector there, and then run a new wire to the sending unit? Should I somehow remove the wire from that C1 connector (idk how to remove the pin from the connector). Then remove it from the harness. Then get a new wire, repin it and put it back in the harness, rewrapping the whole thing. I am curious how people do this. I provided a photo where the yellow wire feeds into the juntion box at the C1 connector. Man have I torn apart this car good to get to the source of this issue.

At this point it seems I jumped the gun in posting. But this thread may be good use to someone in the future, so count it as a blog. With the new knowledge I discovered above I found a way to test the gauge. I plugged the temp gauge back into the car and then turned the key to the on position. I then got my multimeter and disconnected the probe attached to it. I then jammed the probe into the gauge connector where the yellow and white stripped wire was (I figured this must be the sending unit wire). I then hooked an aligator clip up to the probe and then to the chassis ground. And Caboom the gauge shot all the way to 250+ degrees. I believe this confirms that the issue is in fact not the gauge but somewhere in the wire. I will find what went wrong tommorow. I really hate to cut into the harness, but:(

http://www.atlanticz.ca/zclub/techtips/wiringdiagrams/F77ZCAR-WIRING1.pdf Found a wiring diagram. Looks like the wire for the sending unit is yellow and on the middle of the connector one the side where the green(12V) wire is. Problem is my car has both yellow and white where the yellow one is on the diagram. And yellow and black where the yellow and blue is.

Hey Guys, Back again... On the last gauge to fix on the car. Anyways, the temperature gauge does not work on my 1977 california spec 280z (Oil pressure does). It did work when I originally got it, but one day I started the car and it just did not work (2 years ago). Ok so, I grounded out the bullet connector on the t-stat housing and the gauge did not change. So that ruled out the sending unit. I got right to it and pulled everything needed to get to the gauge and pulled the gauge. Simple and easy. Ok so I first wanted to see if the whole gauge was getting power., and it was. I found that the bottom left pin in the photo was supplying 12V. Sweet. From there on I found that the right 3 pins were continous with the chassis ground. I found that the top left one had 84ohm resistance when testing against the chassis ground. Does that sound right? I can't seem to find any electrical diagrams on the 77 showing what each pin for the gauge at the harness does. To make things odder I tested continuity at the bullet connector and it was not 0ohm from the bullet connector to any pin on the gauge harness connector. This makes me think a wire is bad, but thats all speculative. I can't see how the wire is bad, as I looked for loose connections and deoxed the only connector between it and the gauge that I could find. I also tested the sending unit bullet connector against the manifold, battery ground, and other chassis grounds and I got 1 so it was not continous. Don't know what that means. Is there a way to bench test the gauge. Also any thoughts on the info provided helps, I need the group brainstorm. In addition if anyone can tell me what each pin on the connector does that would be awesome. Thank you!

@Zed Head All super helpful. Found the easiest way was to tighten the cable down on the speedo. Then get under the car and press the inner cable until you could feel it seat in the speedometer. Then attach to tranny. Anyways, success. Flipped it 180 degrees and both the speedometer and odometer came back to life. The drill must not have been spinning fast enough to engage the speedometer. I am just gonna go ahead and buy the housing and gear together, as I need the proper gear for the 3.7 instead of the stock 3.53 anyways. The speedo is pretty bobbly, I also have read that this is usually due to friction and such inside of the speedometer cable housing. What is the best way to remedy this? Man it's been a good week. Fixed the car vibration and now the speedometer without spending much money🤪 unheard of for me.

Hey Guys, So I decided to start tackling the problem as to why my 1977 280z speedometer and odometer do not work. When I got the car the odometer had one less mile than it does now, so it at least worked for 1 mile. I never saw it working though. I would like to state that I am running a 81 280zx 5speed transmission and 88 turbo 3.7 LSD. To start, I first completely removed the inner speedometer cable at the transmission from it's sheath and inspected it. The cable is completely intact with the the square end for the speedometer and other end with the key for the transmission. I then pulled the speedometer pinion gear inside the transmission and the gears were lubed and perfectly intact. OK. So I went under the dash and removed the cable from the speedometer and inspected it. Looked fine. So I had a friend use a drill on the cable at the transmission end and spin it up while the cable was in the speedometer. Ok, going counterclockwise the odometer worked, but the speedometer did not. I would like to note the car was off with no key in the ignition. Does the speedometer use anything electrical, or is it completely mechanical like the odometer? It's weird the odometer was functioning but the speedometer was not. The speedometer moved to about 15mph and then stopped there stuck. Ok, so maybe the gauge is boofed, so I hooked the cable back up at the transmission and fired it up. I made sure the cable key seated into the speedometer pinion gear. Whelp, once again the speedometer nor the odometer work. This has me stumped. So #1 is it possible the speedometer cable failed in a way that when the cable is attached at the transmission it no longer spins the speedometer because it can't reach and pulls back out of the speedometer. #2 is it possible the speedometer pinion gear at the transmission is not spinning while the car is in gear. I have read that the 280zx and 280z housings are different for the pinion gears, and I honestly don't remember which one I am using in there. The gear is still completely intact and not damaged so it makes me assume nothing funky is happening there. #3 is the speedometer purely mechanical or does it use an electrical aspect (besides backlight). I have never worked on speedometers so this is new to me. Thank you in advance! Edit*** Did some deep thinking and I'd note I probably drove around 1 mile on the original 4 speed.

@Mark Maras fantastic question I can't answer.

I have these on my car. The silver metal spacer is a spacer for the shock and the top hat to the strut if I remember properly. It will not help gain suspension travel. It is just a necessary piece to make these shocks fit. Black piece is the gland nut. Huge PITA if you don't have the right tool. The knob adjusts the dampening. TBH pretty sure I installed that plastic washer wrong. I used it on my dust bellow to protect the strut.

And to put this topic to rest. Car rides like a soft cloud now. Teleported the Z to Mexico and did some 100+ runs. Didn't feel any shake in the steering wheel or rear end all the way through the gears. I guess you just can't trust new or remanned parts these days. Glad the solution was this though and not the stub axle. I know the stub axle still has its problems and likely will need to be addressed in the future, but as the old adage says "if it aint broke don't fix it". Thank you everyone for your advice and help😄

I think the "defective ujoint" was them making an excuse for an improper installation the first time around. I'd be willing to put money on it💩. Anyways, yes finding the loose gland nut was a huge plus. Now I am going to tighten them up on every shock even if they seemed tight while tugging on them.

@Zed Head I will fix the signature. Anyways, yes I brought my original rusty driveshaft to a shop to be restored and they said the joints were unreplaceable. So they built me a new shaft and called it good. Brought the shaft back today and they covered it under warranty and fixed it/ rebalanced the driveshaft. Turns out it was a defective u-joint. I'll reinstall it and see how the car rides. I am going to guess this is going to fix most of my issue:)

Checked the driveshaft. Found that the rear ujoint had slop, let me know if this ujoint is bad. Seems bad to me. Annoying considering it's brand new, but I will take it back to the shop today. Here is the video. Let me know your thoughts if you think this can cause a vibration. It can move back and forth about 1/4 of an inch. The caps themselves are locked in place, but the joint can move up and down. filtered-740914D1-2972-467C-848B-69B2E58937DE (1).MP4

Got under the ole car pulled on all sorts off stuff and everything was tight. Re torqued the front wheel bearings very precisely as per the manual (21.5ft/lbs) and then backed off 60 degrees. @Racer X that's what I mean by too loose or too tight. If you don't back off the nut after you torque it then it's too tight. Once I finished the job I put the wheels on and gave some pretty hard tugs. Noticed a little slop. Spent about 10 minutes finding the source of the slop, and it turns out the gland nut to the passenger front strut was super loose. Tightened it up and went for a test drive and sure enough the front steering wheel shaking is gone. Still fighting a vibration, but it is much smaller and most definitely from the rear. Pulling the driveshaft and making sure it's balanced good. Then I will go down the route of checking runout:) One step at a time.

Yup:) Going to attack it on Sunday. As you know I just got the car rolling after two years of absolute peril, so putting it back on stands for what will likely be an extended period of time hurts the soul.

@Racer X I think the vibrations are so bad that it is affecting the front wheels, but I don't think it is truly stemming from the front. Anyways while its on stands for peace of mind I am going to retorque the front axles and make sure it isn't too loose or too tight. Quick and easy thing to do. How exactly do I check runout with the dial indicator, and where do I get one? @Zed Head If the stub axle had properly seated bearings, and it fit into the strut casing fine, how would it not be seating? I never really felt much resistance until I tried to seat the companion flange. Anyways when I get the companion flange off is there a way to check for this? If I am going to do this (I really really really hated touching the stub axles the first time) I want to know exactly what I need to check for. If there is anyway I just have to adjust some stuff and replace the companion flange I'd be so happy to save some $. Is there anyway I can just leave the grease in the hub instead of having to remove it?

I'll get a video to you guys when I get it on stands in a few days. You'll see what I mean by the bent companion flange due to me not being able to get it over the splines.

I'll definetly shoot a PM his way. Ok so, I finally got a buddy in the passenger seat with a speedometer app on his phone (mine no work haha). Anyways the official symptoms are. The shaking is super bad at around 45-65mph. At the lower end at around the 40-45 the steering wheel noticeably shakes, and then that fades away at about 65mph. However at 65 the entire car is shaking really bad, but the duration of the vibrations is much faster instead of thump thump thump. The car is pretty much smoothed out entirely at around 79-81mph and it feels much closer to normal, however its slightly still there. It then gets worse as I go faster to about 100. To sketchy for me to try further, and found no reason to. Now for the fun part, I had an extra set of hands so I had him feel around the car where the vibration was the worst without telling him which side had the boofed stub axle. Well he identified the strut tower at the passenger rear as the worst, which essentially confirms that my vibration's epicenter is from the wheel well where the bad axle is. So I think I am going to skip pulling the driveshaft and focus on this as the priority.

Thank you, I’ll reach out if I end up wanting them. The price is a little steep for me and I only need one side.