Backfire out the exhaust

[PlayingWithTBI]

Unsure if it's been tuned, I would assume not. I cannot find the timing disconnect in the usual locations. I had a 94 before and it was by blower motor. Timing was one of my first thoughts, but it runs cool even in the summer (az). I'll try they vacuum deal after work

On the 88 - 90s The gray/black stripe wire (plastic connector) comes out of the wire harness against the firewall on the passenger side just under the terminal block and near the trans tunnel.

You must be registered for see images attach

It does throw a code 32 on the highway. Sometimes it clears itself during driving.

Code 32 - EGR valve, when cruising over 45 MPH and low TPS (both set in Scalars parameters in your .bin file) the ECM will open the EGR valve to reduce NOx. You need to have that taken care of too. These older OBD1 trucks don't always continue to show the CES light but will store the MALF code for so many restarts (also set in Scalars). I have mine set for 5 restarts, it was 30.

 

[gric_az]

Thanks for the pic I'll look there

 

[swb charlie]

On my '88 the gray/black wire for the timing was under the power booster for the brakes. Hope that might help.