Tuesday, May 31, 2016

Fix your DT466E Yourself

 Do You Want to Fix Your DT466 Yourself? 


How to buy 25 years of truck repair experience for $30.00 


When your truck needs to be fixed your repair choices are basically 3:

  • Take the truck to the dealer. Pay dealer prices. Lose more money renting a replacement or doing without your truck.
  • Take it to an independent shop. Wonder if they will be able to fix the problem. Lose money while they try to figure it out.
  • Fix it yourself. Buy one of my books and using readily available tools, get back on the road fast. Save lots of money.

This is what you get with my do it yourself DT466E books:

  • Specific content. These books address specific repairs so you don't waste time sorting through stuff you don't need. With factory manuals, you pay for lots of content you don't need.
  • Complete information. All the information you need is there and is arranged in a logical way. This includes torque specs, special procedures, tool lists, and more.
  • You get experience. In fact, you get over 25 years of experience doing the jobs in the books. 
  • If you have a problem or something is unclear, I am there. Your purchase includes an email address where you can get my help. I have access to factory information as well as experience in repairing these engines.
  • Guarantee. If you don't think the book is what I say it is, I don't want your money. Your Ebay purchase includes a 14 day, money back guarantee. If you buy from Amazon there is no warranty, but if you're not satisfied I will send your money back.
  • The cost of each book is about $30.00, and I try to ship the same day or at latest the next business day. Shipping to the continental U.S. usually takes about 3 days.

Click on the page tab above this post for more information on each book. There are links to the sales points, where you can view samples of the content. 


On the way is a book on more repair operations:
Injector change
Injector cup (sleeve) replacement
Valve adjustment
Camshaft change
Engine oil pump service
Code reading on the dash display

I'll also be posting excerpts from both books periodically, so check back for more.

DT466E No Start book cover
DT466E No Start book
DT466E Inframe Rebuild book cover
DT466E Inframe Rebuild book


Tuesday, April 19, 2016

Problems That Won't Cause a No Start on a DT466E

When working on a truck that won't start it is important to know some of the problems that won't cause a no start on a DT466E.

That way you won't waste time working on something that won't help with the problem.

This post is a section from my book: DT466E No Start Diagnosis. For more information or to buy the book just click on the tab above the first post.

Problems that do not cause a no start
Before going into problems that could cause a no start, it is important to cover some things that WILL NOT cause a no start.
  1. ECM/IDM failure. Although it can cause a no start, failure of one of these components is so remarkably rare that replacement should never be contemplated by anyone but a knowledgeable professional. The replacement will need to be programmed by a dealer, anyway. There are even DTC codes calling for replacement that cannot necessarily be believed. In short, NEVER replace that computer!
  2. Failed IAT, TPS, EBP, EFP, or ECT sensors alone will not cause a no start, but can cause driveability problems or might combine with other issues in a no start situation.
  3. A low coolant level or sensor will not cause a no start, although it may shut the truck down after a period of running.
  4. A bad injector will not by itself cause a no start, and the sudden failure of a set of injectors is extremely unlikely. There are injector-related exceptions:
  • The injector fuel seals can fail and cause a no start, but this condition will cause low fuel pressure, and probably fuel in the oil.
  • In 2004 and later engines the oil inlet pockets in the top of the injectors can wear and cause a no start, initially when the engine is hot. This sometimes necessitates changing all the injectors.
  • Leaking injector seals can cause a no start, usually initially when the engine is hot.
  • A very high mileage engine may have a set of worn injectors that finally cause a no start condition, but this will have been preceded by hard starting, rough running, and smoking when the engine did start. Often these engines will run after being started with ether.
  • Another exception is the rare occasion when an injector tip valve sticks open; this can cause the cylinder pressure to pump lots of air into the fuel system. The fuel pressure may be high and the engine will certainly shut down and fail to start, after a period of running.

Sunday, March 13, 2016

An IDM Problem on a 4300 DT466E

A customer truck had been plagued with intermittent no start problems. For instance, once it was in for a service and it started on the lot to pull it in for the work, again after the oil change, then again to pull it out and park it.

When the customer came to pick it up the next day however, it wouldn't start and was throwing codes for low IDM volts.

I dragged the thing into the shop, where it naturally started right up.

Testing the IDM circuit

The standard test for the IDM circuit is to plug a sealed beam headlight across pins 30 and 87 of the IDM relay socket. I did so and the headlight lit brightly and remained lit for over a minute, so the circuit passed the test.

The relay was also a possibility, so I swapped it with the horn relay and blew the horn several times, including a long blast causing a negative reaction from my shop mates.

Even though the circuit seemed good I had to check the battery box. The Weatherpack connectors to the IDM and ECM are prone to problems in the 4300 model. However, on this truck I had already cut the connectors out of the harness and soldered the wires together in an earlier version of this same issue. The battery cable ends looked OK, but I've been doing this long enough to know that just looking isn't good enough, particularly when you know there is a problem. I took all the ends off the batteries and cleaned them all up, although they appeared good when taken apart.

Back again

Despite the fact that I didn't find a problem, the customer needed the truck. A few days later the truck was again at the shop. One of the other guys had gone and jump started it after it again failed to start and the driver had cranked the batteries dead. Now it wouldn't start for me, either. Before pulling it into the shop I wanted to try to see what was up while the no start condition was active.

The scanner pulled codes for the IDM and batt volts, but those were inactive and probably the result of the batteries being cranked down.

I was really getting tired of this truck and this problem and the customer was less than pleased also. I really needed to nail this thing somehow. Sometimes a fresh pair of eyes is needed for something like this, so we had J. take a look. He is the resident shop genius at electrical diagnosis and the go-to guy for really tough problems in general.

He couldn't find anything, either. However, a couple of times during all this the thing did fail to start, but without attendant codes.

4300 fusebox corrosion

Above the driver steer tire is the fusebox containing the module relays and fuses. I took it apart to check the connections on the back of the relay socket. On 4300 models the box is prone to corroded contacts often causing no starts. This one was clean and all voltages were getting through. Now it was time to really look close at the rest of the IDM circuit.

The wires that feed the IDM and ECM relays are wrapped in fabric tape and run along with the battery cables. However on this truck somebody had repaired the circuit to the IDM relay by splicing in a piece of wire. The splices were covered with tape, which is always a bad sign. Under the tape were shrink type butt connectors. They were good quality, glue-lined connectors, but they had been crimped with a crimper for uninsulated connectors, which pierced the insulation and let road salt into the splice.

When I cut these connectors out to redo the work I noticed the wire had also been pierced with a test light not once but in 3 separate places, and those spots were also corroded. I replaced the splices with new wire and uninsulated butt connectors, which were then soldered with rosin core solder. The ends of the wire could have just been soldered together but I find it easier and neater to first connect the ends with a butt connector, then add solder to the joint. The connection is then covered with glue lined heat shrink tube for a weatherproof seal.

After this repair the truck started every time and also the next day. It has now been in possession of the owner for over a month with no issues.

Proper circuit repair is critical

This no start experience highlights several things:
  • Never pierce a wire's insulation to check a circuit. You may get away with it inside a cab or another place protected from the weather, but certainly not under a truck and not on a critical, high amperage circuit.
  • If you use shrinkable connectors for a repair, use the proper crimper so the insulation isn't broken.
  • Don't even bother using electrical tape to protect a connector from the weather. It just doesn't work. At least use a shrinkable, glue lined connector. For any circuit to a computer or a circuit critical to vehicle operation, use a soldered connection covered with glue-lined shrink tube. 
  • I was always told that the headlight test for the IDM circuit was definitive, but apparently that isn't so. In this case it looks like there was enough circuit capacity to light the headlight, but not enough to power the IDM.