chaseincats

I changed my motor to the kia one a few years ago and immediately noticed a difference in terms of fuse consumption. I went from changing them every couple weeks to every couple of months.

So the resistance created by the resistor in the fan case does not move backwards into the fuse?

I was under the impression that the fastest fan speed setting was the best for the car since it wouldn't be using the resistor in the big fan case under the dash (I dont remember what its called).

Sorry to bring this back up but did you ever find out what was causing this Dave? My fuse is getting pretty toasty too.

It isn’t, I’m guessing that’s part of the crane system.

We ended up cleaning the terminals on the dropping resistor and now the car idles really well. After the fact, we measured all of the injectors through the ECU connector and they all ready ~10.5v. I checked the dropping resistor power wires, the main power wire was battery voltage and the one on the top left was around 10.5v (same as the injectors). Not sure if that's how its supposed to be, but now it's idling well.

Hi guys, Working on my friend's 1975 280z and when you connect the blue tach sense wire to the negative terminal on the ignition coil, the car will stall (and also won't start if already connected). He has the Crane XR700 ignition system if that helps at all. When I connect the blue tach sense wire and crank the car, the tach will move meaning it is connected but won't start until you remove the wire. Any ideas what's going on here?

Sounds good. He is getting the car back today and will clean the terminals on the dropping resistor just in case. I'll let you know the results and take measurements next time I'm over.

Yeah, they were all off when we took measurements - we just went from one to the next. It did run WAY better after cycling them all but that was only temporary. My guess is cycling them in the cylinders so many times eventually got enough gas in each one for it to run properly. After that was burned off it did go back to running how it was prior to cycling them.

This is with the connector disconnected from the injector - literally touching the female connector pins with a multimeter that the injector's would plug into. We did confirm the the injectors work by using wire leads directly to a 9v battery with the connector disconnected. Injectors 1-4 that were now accustomed to the low voltage had a considerably fainter click than injectors 5-6 but after clicking them on and off 9v a few times, they began to come back to life and the audible volume of their 'click' gradually began to match injectors 5 & 6.

Good call - I'll relay the message.

Fair point - basically it won't run unless the coolant temp plug is pulled so the car runs in 'max rich' mode. You need to be VERY gentle with the throttle or it will die. After it's warm, you can plug the coolant temp ECU plug in and it will idle but will die with pretty much any throttle input. We smoke tested it and there are no vacuum leaks. It has new air and fuel filters, we adjusted the valves to factory spec, and cleaned all the contacts here except the dropping resistor.

Yikes, it's very possible that is what is going into the engine - he really should empty the tank.

Is that one of the relays located in the under-hood relay bracket?

The injector connectors have been replaced and look fine - I will let him know to check out the dropping resistor and ECU connectors. What is the connector you circled on the bottom of the chart - I don't see it labeled

Gotcha - it's getting pulse to fire, its just very weak.

We measured across the injector connector. Wouldn't that be the best place to measure it since it would isolate the plug itself?

Hey gang, My friend picked up a 75 280 and its not running all that great. We found that injectors 5 and 6 have 10.3 volts with the key in 'on' (but not running) but injectors 1-4 have something like 0.3v. According to the FSM, there are two dropping resistors, one that covers injectors 1-4, and one that covers injectors 5-6 so I'm assuming those (or the connectors) would be the problem. I have never heard of those going bad or causing problems though. I thought the injectors were supposed to get 6v after the dropping resistors - anyone know how they could be getting 10.3?

Interesting, got it. Regarding the combustion gas in the coolant, I'd guess I would see small bubbles in the coolant with the cap off if that were the case though, right? I ran it with the cap off when I changed the coolant to make sure everything was good and didn't see any with the car at 170. I can go grab the test kit and test anyway if you guys think its still possible without visible bubbles.

After I changed the radiator, I had enough coolant to fill the radiator to the top but not enough for the bottle. I figured the radiator would fill the bottle if the engine got warm enough so I didn't get more coolant. Is that not the case?

Alright, I'll give it a look. The heater core is connected - I did not turn it on while testing the temperature max though.

It has a 170 degree thermostat currently. The thermostat that was in there was a Nissan center feed 170 degree thermostat, and after putting the new 170 one with the offset valve (before changing any other part of the cooling system) I had the same issues so it shouldn't be that. I do remember it getting even hotter last year when i was sitting in traffic with the AC on so it really shouldn't be the new thermostat. Is the radiator throwing coolant into the overflow bottle the sign that things are too hot? Basically asking if I should care what the temp gauge is saying if it's not hot enough to push coolant out of the rad.

More numbers for you guyw More numbers for you. Today it was 95 and after a long drive with the AC on the whole way, with the sun directly shining on the hood, when I got off the highway it got up to 203 when I shot it with the IR temp gun when I got home. I put water wetter in it the other day for what it's worth. I took a look at the overflow bottle (which was never filled but I filled the radiator to the top of the neck and it was empty if that helps at all. Any ideas?

I'm guessing at this point its stuff hanging out in the coolant passages not the radiator. Regarding the IR temp gun, I tried that today and the gauge is indeed reading right. With the car in my shady garage it was apparently around 88 degrees in there and after running for maybe 15 minutes with the AC on and the hood closed it got up to around 195. Any thoughts on that number?

I used oreilly's generic flush chemical a month or so ago and did the low budget fix of 'the garden hose in the thermostat housing' which got a fair bit out but didn't change what the gauge had to say.