safc causing dead tach
 

okay ..

when i first got my car back from landers it ran great for about 2 days ..
then it would just start up, but die immediately..

just like if you leave the afm unplugged..

found out it was the wires that you hook the safc up to.. the rpm wire and the afm wire

so i got those soldered up good and heat shrinked and everything...

didnt have a problem with the afm wire ever again .... the tach seems to be more finiky .. sometimes it just wont work .. i have to turn the car off and then restart it...

new years eve night, i go to start the car, and it does what it did the first weekend of getting the car back .. starts up then immediatly dies so i start gathering my tools from the hatch to take the kick guard off and jiggle the wires, but before i turn any bolts i try one more time and it starts like normal...

this is starting to piss me off .. thats the first time that the car acted like the afm wire was cut since i soldered them together ..
however the Tach will sometimes not work ... i start the car up, the tach reaches about 400 rpm and then dies .. the car runs fine, but the tach is dead ...

i can usually turn the car off and then restart it and the tach works, but this is just getting annoying ...

has anyone else ever had this problem .. its got to be the safc interferring with the signal, but it just sucks that sometimes it happens and sometimes it doesnt

my battery is really weak right now .. could that cause the safc not to initilize correctly or somthing and cause it to not read the tach wire?

Finiky RPM guage
 

im with you all the way on the tachometer . after i put mine on it took about a week then all of a sudden it was completely dead . i thought the cable had popped out from behind(84gsl-se turboII engine) anyway i had to turn the car off ,but when i restarted it i worked fine . 10 minutes later it was slowly dying , went from 1k rpm then 900,then 800 then 500 then just died. i know its the wideband since we tap into the rpm wire in the ecu , signal must interfere with tach causing it to malfunction. i will disconnect it and just tap it into the wideband that also reads rpm . long term it will probably damage your stock tach . havent been able to start the car this week since i rewired the safc tps wire to the boost sensor now it wont stay on ,so i have to read the manual and check all the settings . once it stars ill let you know how fraky the tack is. as far as the car shutting off i didnt have a problem after i install my safc . it ran fine , i soldered all the wires and rechecked them just to make sure . have you checked your settings ?

Maybe its not your AFC at all man. My turbo had the same problem and it just turned out to be the stock harness out by the leading coil. The harness will get stretched and it will pull the pins out of the back of the connector. Check both the leading and trailing coils. Its only one wire that splices into the rpm signal, its either a bad connection or its not... know what I mean?

will definetly check it out tonight