Truck running rough above 2500

[B_rentum]

So, i have a 1994 D21 189,000 miles i have replaced fuel pump, filter, plugs, wires, rotor cap, rotor. checked MAF (Checked fine). the truck has never thrown a check engine light and only runs rough after about 10 minutes and countinues to run worse until it will not run at all. it also smokes and smell a bit gassy. would anyone know what would be causing this egr maybee or 02 sensor im running out of money and ideas.

[Rev_D21]

Have you checked to make sure the distributor is timed correctly? If it has ever been out of the truck, ie. timing chain replacement, then it might not have been reinstalled properly. Also another item that really affects the performance on these trucks is the coolant temp sensor. Some food for thought!


Welcome to NICO!!!

[B_rentum]

I have not checked the timing, its a 3.0l so timing belt whats the chances of slipping timing on the timing belt, ill check the coolant sensor in the four years i've had it it never gotten more then an eighth of the way above the cold mark while driving, it was all of a sudeden one day started doing this.

[B_rentum]

and i have never had the distributor out, its my off road camping truck, I did get it stuck in a lake for a period of about three hours, which im wondering if the 02 sensor or cat are shot I wouldnt think the cat would cause the vehicle to smoke ill change out the coolant temp sensor and 02 sensor first and let you know the results.

[Rev_D21]

A plugged cat is possible.