sr20det tach signal issues

[hwy1]

I've searched this topic for 3 days now and every thread about it has no conclusion, only more people with similar problems.

Ok, so I have a 1990 s13 with a blacktop sr20det. I'm using the stock gauge cluster with 9k sr tach swapped in and it doesn't work at all. with everything plugged in/hooked up, I checked the sensor wire (Red/yellow) and it read 6 volts! so i cut the wire and checked it right out of the ECU and I got 3.8 volts. I then check the wire going into the dash and it read 6 volts.

First off should there be a volt reading from under the dash with no sensor wire hooked up? and what could cause the ECU wire to read at 3.8 volts? Any help is always appreciated. thanks

[hwy1]

anyone? anything? please, I'm desperate

[Z U L8R]

in the wiring there's a condensor which condenses the tach signal, you may just have a bad dohc cluster. try another one or try your 90's cluster, it'll read fubar but it should read, if you determine the problem to not be in the cluster, than run your own wire from the dash plug to the cluster. or buy an autometer tach and wire the signal wire to the white wire on the ecu pin 30 or 22 it doesn't matter, aiight @@ gl =]

[Big Bronze Rim]

When I wired up my sr years ago, I recall that the tach signal wire (yellow/red) had no signal and the tach wouldn't work. I ended up tee-ing into the CAS 180* signal from the ecu and the tach works great. I don't have a pinout here at work but you should be able to look at one and figure it out. I found that info on FA a long time ago and it seemed that alot of cars have a dead tach signal wire.

[hwy1]

I know my tach is good its just that the signal wire is running to many volts (about 3.8) when I belive it should be sending millivolts. anyway thanks for the help. I think i'm just going to run a wire from the cas 180.

[hwy1]

Ok so I tried the 180 wire and it still didn't work. the tach is getting power and ground but the signal connector on the back of the tach is producing 6 volts. does that mean my tach broken?

[Z U L8R]

dunno, but while you got the cluster half in half out, try your sohc one like i said, pin 30 and 22 IS the 180 white signal wire from the cas, that's what i was saying also lol, but anywho i don't think that dohc cluster is good mayng @@

[RHD_S13]

Did you find a definitive fix for your issue? I'm having tthat same issue. How does the pinout go on the ecu. Like where is 1 and which way do you count, long ways or short?

[jedi03]

i had issues with my tach recently...coil ground broke...fixed it an no issues now

[RHD_S13]

Ok ill check that too. Was it the ground on the valve cover or a ground somewhere in the harness?

[RHD_S13]

Ok, I tried another yellow/red wire I found coming out of the ecu, no luck. So i tried the CAS 180 wire (pin 30) still no luck. I'm at a loss.

[tac 1]

Try another ecu, I had this problem before. I was getting some reding from tach signal but it wasnt stable turned out I had bad ecu.

[RHD_S13]

I cant get another ecu. Mines a aftermarket ACTIVEROM FEILD 63 ecu, and was tuned in Japan before being shipped here

[tac 1]

^^This is one of the reason why im going lsX next time I buid a 240. Lol GL

[wangan_cruiser]

check the connections where it was spliced or soldered. i had the same problem before and my tach works on and off. turns out the soldered part broke in 2 piece.


or you can do a contiunity test with a vom from the ecu pin out and the wire behind the gauge cluster.

[RHD_S13]

Ok so no luck on anything. I'm gonna run thru and do a grounding kit, and check all stock grounds. Also I plan on tieing into the ignitor and seeing if i can get a possible signal there. But im running into an issue, I can't find the ignitor lol, sounds odd i know, considering the car runs and it runs great! Can anyone send me a pic of their ignitor and its location?

Thanks