Bought my 2nd fc a couple days ago, 108k all stock, runs and drives great, no problems for the first day i drove about 100 miles.
the next morning i started it up and the tach did not work, so i checked all the fuses and stuff and they were all good, so i swapped in a known good trailing coil and still didnt work. So i proceeded to drive to school and as i was on my way the fuel gage and temp both slowly moved all the way up as far as they could go. And they both did it at the same time so i assume they are related? Well after a couple more minutes they both gradually moved back down to where they should have been and my tach shot up to the correct rpm.
and i didnt have any problems for a couple more days then this morning the same thing happend except the tach worked perfectly

 

Check your ground cables. Same thing happened to me late last year, my ground cables had melted. I used my multimeter and checked em and then replaced em. Fixed the problem right out.

 

Thanks ill check out my grounds, did your multimeter show the condition of your cables or was the only indicator the fact they were melted?

 

Thanks ill check out my grounds, did your multimeter show the condition of your cables or was the only indicator the fact they were melted?

 

Thanks ill check out my grounds, did your multimeter show the condition of your cables or was the only indicator the fact they were melted?

 

Thanks ill check out my grounds, did your multimeter show the condition of your cables or was the only indicator the fact they were melted?

 

My phone is on the fritz, sorry for the reposts.

 

I thought it was just slightly melted then I took a look at it and saw how it was basically non existent as I went down te cables. I was getting no readings from the multi. But that's cause it had melted thru. Moral of the story: don't cut corners to ground it. Use a sturdy cable.