DT 466 Diesel Engine Fuel Pressure Test

DT 466 Diesel Engine DT/DTI/DTA (C Engine) Fuel Pressure Test with a Robert Bosch 'MW' and 'A' Fuel  Injection Pump.

The primary reason for checking fuel pressure is a performance complaint which could be caused by low fuel pressure or restricted flow. This simple test will help determine firstly if the filters are plugged or if there isn't enough flow to the injection pump.

The fuel pressure test on a DT 466 Diesel Engine with the Robert Bosch injection Pump is a straight forward procedure that requires a fuel pressure guage that reads up to 160 psi connected to the vent plug located on top of the secondary fuel filter housing. 

DT 466 Diesel Engine Fuel Pressure Testing Procedure

The fuel pressure has to be a minimum of 20 psi at engine high idle (no load). High idle is full throttle (linkage contacting high idle stop), transmission  in neutral.

If the pressure is low... replace the fuel filters. Retest fuel pressure and if the readings have not improved the next step is checking the 'transfer pump inlet restriction' (coming up in my next post).

The DT 466 is a mechanical injected fuel system and as you can see troubleshooting is pretty straight forward. No laptops required :)

The first reaction to low power complaints is to replace the fuel filters and most of the time that will be the cure. It's also interesting to see how much of a difference the filters make before replacement. 
The next post will be all about testing the DT466 for 'transfer pump inlet restriction'


Comments Welcome!

DT 466 Diesel Engine Overview

DT 466 Diesel Engine Overview & Why I Think They Rock!

I found that Wikipedia is a great resource for information. For example here is a link for info on the DT466 Diesel Engine. That's what the Internet is all about..... The 'information highway' as you may have heard before is what the internet is here for. Google has a mandate to supply the best information online to answer your question. If you need diesel engine information... 9.99 out of 10 times you will find the details you are looking for. 


That's my plug for Wikipedia, I've used it many times before for basic information. But now I want to plug my own experiences and thoughts on the DT466 as I know it. 


These diesel engines were designed for the owner operator/fleet operator. They have a wet sleeve...this is the key. You can rebuild in-frame and save a ton of time and money.


If you have ever rebuilt a dry sleeve engine you will know exactly what I mean. Imagine you have a collapsed piston and you have to pull the head, oil pan and remove one of the pistons that has either scored the liner or has broken a piston ring. 


A dry sleeve design means the complete engine has to be removed, stripped down and the block sent out to the machine shop for boring and re-sleeving. You need to find a very good machine shop that knows what they're doing. 


OK pain in the butt right?


Now looking at the wet sleeve design of the DT diesel engine all you need to do is pull the head and the oil pan...replace the liner and piston kit. Done..bingo bango kick'er out... back into service!


So if you're looking for a good used truck, try as hard as you can to find one with a mechanical injected DT 466 Diesel Engine! 
My 2 cents...


Please Comment!