alanburton

Ok I need some input here. I ordered what was to be a NOS oil sender. It came in the correct Nissan box and all. His was to replace the one I had which was very erratic at best. I put the new one in and connected it and when I started the car it read nothing at all, then after a couple of minutes it started reading about three-quarter scale and then drop back to zero. The car is running just fine I heard the valves clicking or any indication that the engine is under stress. I thought maybe it’s dirty contacts on the connector so I pull the connector and clean the contacts and the connector with electrical cleaner and plug it back in. When I did this and got back in the car the meter was reading for scale it was pegged however as soon as I started the engine it went to zero. When I turn the engine off it goes back over almost all the way with the engine turned off. And here’s another One for the voodoo file. When I get inside the car and the meter is on zero and I stick the key in the ignition without even turning it on the meter goes to three for quarter scale, where the ignition off. When I unplug the connector from the sender Meter reads zero as it should, but is soon as I plug it back in when the engine turned off there it is three-quarter scale. It almost sounds like I got another bad sensor what do you think Sent from my iPhone using Classic Zcar Club mobile

Appreciate the feedback. Looks like the variable resistance connector goes to the meter with the changes in resistance to ground results in changes to the oil pressure meter while the other prong goes to the oil light and goes to full ground potential when oil pressure is not present. If that’s correct I at least know how to start testing. Sent from my iPhone using Classic Zcar Club mobile

Trying to figure out completely erratic readings on my oil pressure gauge. I ordered a NOS sender and it’s still crazy. So I’m wanting to narrow this down. There are two prongs on my sender and somewhere I read that one prong was for the meter and the other prong was for the oil warning light, is that true. If so the changes in pressure would result in changes in resistance to ground for reference. What I wanted to know was is the Oil pressure reading resistance across the two prongs for both the light and meter or is it reading reference of resistance to ground on each with one going for the meter and the other going for the light. Any insight here appreciated. Sent from my iPhone using Classic Zcar Club mobile

Also if you want to try this make sure to order the switch that is N/O or Normally Open. I’m using one set for 50°C or 122°F Sent from my iPhone using Classic Zcar Club mobile

There is a timed relay that is triggered by a grounded connection to the sensor wire connected to the thermostat. Once the ignition is shut off the fan timer is in a ready state. If it sees ground on that connection it will start the fan and allow it to run for a programmed period of time (10 - 15) minutes and then it shuts the fan off. If you were to turn the ignition back on and then off again and the temperature was still hot enough to open the switch to ground it would replete the process. If however you left the ignition off it could not be triggered again. Sent from my iPhone using Classic Zcar Club mobile

When the factory temp switch sees a temperature of around 190 degrees or somewhere there about the switch opens the connection to ground. When the ignition is turned (off) and this ground connection is present the fan timer kicks in and runs the fan for several minutes and then turns the fan off. As earlier stated I could never get the factory switch to work even on the hottest days but this new switch works very well for me. Sent from my iPhone using Classic Zcar Club mobile

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F401445968168 Sent from my iPhone using Classic Zcar Club mobile

Yea I had driven the fire out of my car for about two hours and then parked it for about 10 minutes and those fuel rails must’ve been boiling because I really had to put that throttle to the floor to get her started. That was the first only time I ever had that starting problem but that’s when I decided I was going to do something to lower the threshold for when my cooling fans came on. Prior to adding this new switch I couldn’t drive it hard enough in hot enough weather to get it to come on. Sent from my iPhone using Classic Zcar Club mobile

You can see the temperature switch it’s the little shiny silver thing. There are two leads, attach one to the bolt on the valve cover to get ground. I put a female bullet connector on the other wire and then simply unplugged the single wire that’s attached to the temperature switch on the thermostat housing. Just disconnect that wire plug it into the other wire on the new switch and you’re done. I found the switch on eBay for less than two dollars from China Sent from my iPhone using Classic Zcar Club mobile

Sent from my iPhone using Classic Zcar Club mobile

I drove my 83 280zx until the engine was hot enough to cause a vapor lock on start up after being parked about ten minutes in 90 degree heat. The fan that cools the fuel rails never kicked on. I knew the fan worked properly because after turning the engine off I pulled the lead from the thermostat switch located on the thermostat housing and ground it, and immediately the Fan started working. I knew then that my problem was the fan switch the screws into the thermostat housing so I ordered a new one and replaced it and I still got the same result. I don’t think the Fan would’ve kicked on if the engine was on fire. After that I searched on eBay and found the small thermostat switch that is normally open but closest when the temperature reaches 122°F. I simply grounded One side of the switch to a bolt on the valve cover and then plug the other end into the wire that I took off of the thermostat sensor. Now it works great, take my car out on a hot day and I Park it and my cooling fans come on every time. I’ve attached a picture of the small sensor Showing the way I attached it. You can find these on eBay for a couple of bucks, just make sure that you get one that’s normally open, and is the correct temperature that you’re seeking. The 122°F as work great for me. Sent from my iPhone using Classic Zcar Club mobile

I have a 1983 280zx that did the same thing. Hesitation when cold then ran smoother when it warmed up. I took some advise and went to Walmart and purchased Berryman file system cleaner. It fixed my problem. It’s cheap I now add a can with each tank of gas. The car runs smoothly hot or cold. Sent from my iPhone using Classic Zcar Club mobile