92CamaroReallySlow

Well I have been having problems getting my tach to work at all. I had the guage checked out and it was fine, I made sure the tach signal adapter was fine and it is. So I tested the Engine Speed (Tach) Output Signal on the PCM and I was getting no reading out of it. Also for the hell of it, I hooked up the negative of one coils to my tach wire and sure enough the tach moved with engines rpms (approximatly 1/8th what it should read, but it read it none the less). My question is, why wouldnt the computer not be giving the engine speed output? Can it be solved or fixed someway, or am i going to have to hook up my tach to the negative of one coil and have my adapter sent back and have the signal be multiplied by another 8? Also, all of my friend found this odd, but my oil pressure guage is always reading max, but when i ground the wire it goes down to zero, doesnt it usually work the opposite way? Any ideas? Also I have the Oil pressure output signal hooked up to that oil pressure guage wire and it doesnt do anything but stay at max so Im confused. Any ideas are appreciated. Thanks,

Chris

technical

You have a grounding issue. Something isn't hooked up correctly... sorry for stating the obvious.

92CamaroReallySlow

All the grounds are grounded. Three on the back of the driverside head and one ground strap. Unless there is a magical ground that I cant see, then I dont know.

technical

Are they making good contact? and do you have continuity?

92CamaroReallySlow

Well good contact is being made. As for continuity Im an not sure what that is. How would I test that?

technical

Multimeter or continuity tester. Since it's a ground you can't really use a test light. Basically continuity means there's no open and the wire's integrity is intact.

NOSjohn

iTrader: (9)

Are you sure you have the correct wire for Tach. signal? If so, which one did you select for it?

digitalsolo

iTrader: (24)

yeah, which wire are you pulling? There is on in one of the "C" connectors (C105, C100, C101) and one in the white or blue dash plug depending on year. Dash plug is the one you want.

edit: I see you have a '98 like myself. It is the (white I believe) wire in the blue plug in your dash harness section of the engine harness. I'm wired off of that to my autometer and it's spot on.

92CamaroReallySlow

Im sure that it is the right wire that im testing. Its the white wire in the #35 pin location in the blue connector. That is directly routed to the tach adapter and I know the wire coming from the guage is right because we grounded it for a second and it moves and we got it to work off the negative sides of one of the coils. We put a pin in the #35 pin location and ran it directly to the guage wire to make sure that there wasnt any bad connections between the pcm and where the wire comes out of the loom, and we could not get any reading from the PCM. And as for the continutity tester, is it just making sure the grounding surface isnt getting any sort of power or anything? I dont have a mulitimeter or continuity tester.

ls1canuck

I know this is a little off the subject, but I hooked up my aftermarket tach directly to the white PCM tach signal wire, and set the tach to 4 cyl. mode, and it works great. No adapter. Anyone else done this?

GTA91

iTrader: (14)

Ever figure out your tach problem? I've got a '98 setup in my car as well and I'm using that white wire on pin 35, along with a tach converter box from Baker Electronics... my tach works fine until high rpm (5k or above and it drops down). really weird... wondering if you could shed any light on this for me.


*As for yours not working, that pin 35 is the PCM's tach output to the TCS... is your PCM by chance from a non-TCS car? Would that be why you don't have a signal coming from it???