Mike's 1993 Dodge Cummins Truck Blog

Today I looked at the source of the fuel leak more carefully. It looks like it’s comeing from the governor shaft seal on the top of the fuel injection pump. The previous owner said he had not had it apart.

After reading even more posts in the Cummins forum I found that there are video’s on youtube that some guy posted on how to debug several things on the Cummins Diesel. One item was the tps. It is suppose to have a 1.0v output in the idle position. Mine was at .3v. So I adjusted it as close as I could get, 1.01v. Also the full throttle position is suppose to be around 3.5v. It was. So now the tps is dialed in and the trans is still shifting into and out of overdrive just likes it’s suppose to !!!! Looks like all that is left is to drop the pan to change the fluid and adjust the bands.

BTW the air conditioning works very well!!!!

The door locks were in major need of help!! Here I am with the door panels apart and repairing the door locks and the electrical wiring. I had to have keys made from scratch for the doors since they didn’t match the ignition.

So I have been researching in the Cummins forum for info on the transmission. It’s basically a 727 with overdrive. The tps or throttle position sensor is used to tell the transmission when to shift into overdrive. As it turns out my transmission works fine as long as the overdrive is shut off. I found that several owners had taken out the factory tps and put in a pot that mounted to the dash. This seemed to fix many of their overdrive issues. So this morning I took off the tps and found that it is not being turned as the throttle is moved. The female hex on the throttle shaft was a bit damaged. The adapter that connects the tps to the throttle shaft is adjustable. I made sure the tps would rotate as soon as the throttle was touched. That cured the overdrive issue!!! Now it shifts into overdrive right around 35mph just as it’s suppose too!!!