Advancement timing wire on a 94' Chevrolet Pickup

I have a 1994 Chevy pick up 5.7 liter engine. I rebuilt the engine and have put around 2800 miles on it since. It started popping back through the throttle body and I thought the distributor was loose but it wasn't. I've checked lobe wear, fuel pump pressure, new throttle positioning sensor, new oxygen sensor, new coil (it was breaking the plug wires down).


I'm trying to find the advancement timing wire coming from ECU. I've looked on the firewall and under the dash, but can not find it. Your help would be much appreciated, thanks.

It's the Black/tan wire. The connector is usualy located under the black plastic cover on the passenger side firewall. Some are located near the ECM behide the glovebox. I've even seen a few posts where there was NO connector and they had to cut the wire and splice a connector on.
If reseting the timing doesn't cure your problem, you may want to pull the distributor and check for wear. Had a similar problem once before and the reluctor in the distributor was cracked.

Just a thought , but i have a 2000 silverado that was popping back through the intake like that , and it was bad plug wires which also destroyed the porcelin on the plugs.

On my 94 it is is just to the left of the ecm. I had to pop the inside of the glove box out to see it.My friends is down lower by the heater box straight below the ecm.

I have a 94 k2500 w/305 and the timing wire is located just below the glove box a black connector on a single wire (brown I think).

I hope this helps....

EvaderX

Thanks, all. It was under the dash, behind the radio.