I swapped an 87 base N/A motor into an 88 GXL chassis. I am using the 87 harness and ecu. After hooking up everything that I can see, I have no spark and no tach signal.

-CAS is good and plugged in.
-When key in turned to "on" (before cranking) the tach needle "bumps" like it is energized however does not move during cranking.
-Both coil packs do not fire.
-I am using the original 88 wiring harness that is on the drivers side of the engine bay that connects to the engine fuse block, the coils, etc...

Something I noticed:

On my 87, the main relay was non-present but instead jumpered w/ a connector and a wire.

With the exception on the ignition switch the 87 motor ran fine prior to the swap. Because of this, all the components on attached to the motor itself are already proven good. I believe the problem lies in the wiring. A bad or non-present ground perhaps? Incompatibility w/ the harness perhaps?


PLEASE, PLEASE, PLEASE respond as promptly as possible with any suggestions. I am on a very short time schedule b/c my good buddy slow87turbo has lent me his car for a week. That was three days ago and I will not have access to my cars thursday or friday.

Any suggestions will be greatly appreciated.

 

if the tach is jumping then going dead, you have something crossed,it is very reasonable that the wiring harness' between the two are not compatable, since they were different variations to begin with. try swapping out the gauge cluster as well.

 

check
afm
bATTERY
STARTER...<---- important MAKE sure you installed correctly.

 

Um, one thing (not the only thing) I learned from aaroncake is that even though the bridge fuse "looks" visually good....

....it still may not be good.

In other words you might look at blown fuse and visually see it to be good....but it's not.

Replace the 15 A engine fuse in the drivers side panel

Again. I don't really care what it "looks" like

replace it with brand new fuse.

Then go from there.

 

Go to the LEAD coil assy. PUll the small white connector off. It has two wires. Put your meter on the black/yellow wire and with the key to ON, see if 12v shows up. NO 12v?? Go to the fuses in the engine bay. The 30a fuse feeds that black/yellow wire. Is it any good??? Good? Then go to the MAIN RELAY. Pull the four socket connector off the MAIN RELAY. You should have 12 on the Black/Green wire and the White/Blue wire anytime, key on or key off. Voltage is there on those wires? Pull the two socket plug off the MAIN RELAY. Put a meter on the Black/White wire. Turn the key to Start. You should have 12v there when going to START. Now the other wire on that two socket plug....check for a ground on the Black wire. You should have less than .3 ohms.

Of all the above, if you do nothing else at all......see if there is 12v at the Black/Yellow wire on that small,white, two socket connector on the LEAD coil assy.