Need a wireing diagram for distributer on 1991 gmc 2500 sierra

Nobody has a diagram. The smallest ones usually go in the cylinder head

Sierra 1500 also C/K Series have three engine sizes; check this...

1993 GMC C 1500 P/U 5.0 liter V-8 VIN "H"




1993 GMC C 1500 P/U 4.3 liter V-6 VIN "Z"




1993 GMC C 1500 P/U 5.7 liter V-8 VIN "K"




Hope helps (remember to rate this answer).

Here is the firing order diagram for the 5.0 liter (305), 5.7 liter (350) and the 7.4 liter (454) V-8 engines (note position of locking latches/screws between the 3 and 6 and the 1 and 2 terminals on the distributor cap). Let me know if you need the 4.3 liter V-6 engine diagram (hopefully not in a 2500 series truck) or if you require any further assistance.

GMC Silverado also called Sierra, Chevrolet Cheyenne and GMC Sierra Denali (only Mexico)
- Vehicle Wiring
- Wire Diagram GMC
- GM Full-Size Trucks 1988-1998 Repair Information (free register)

I hope helps with this. Good luck (remember rated this help).

2.4L Engine
Firing order: 1-3-4-2
Distributorless Ignition System


3.0L Engine

Firing order: 1-2-3-4-5-6


3.3L & 3.8L Engines

Firing order: 1-2-3-4-5-6
Distributorless Ignition System

here is the diagram for your engine...
click here


Follow the locations on the cap illustration..

Go to your local auto parts store and look for a book, Haynes Diesel Engine Repair Manual, Part number 10330. It has your wiring diagram and a lot more. I got mine at Canadian Tire.

I dont understand why you would need that unless you took off all the wires and took out all the plugs and forgot how the wires were.I have the same truck and I always do the plugs and wires one at time to make sure I make a mistake.If this is your ploblem let me know because i might be able to walk you though it.

Well, the IAT (Intake Air Temperature) sensor is located on the air intake duct between the filter and the throttle body (Assuming you have the 6L motor). The wires are easily visible at the plug that connects the sensor to the wiring harness. That's the easiest place to access them.