Here's part of whats coming for '04 model year.....

[dmaxalliTech]

There has been alot of discussion on whats changin for next year... I have contacted some 'inside' people at GM Training Center in Detroit and this is the info I recieved. Please note, I have no further details then what is posted below.

Will use an electronic EGR valve setup, will meet stricter emissions then CA requires. This includes all trucks, not just CA emissions.

Will use a Cat Conv, again, to meet high emmision standards

Will use a variable nozzle electronically controlled turbo. Will apparently be more linear. Dont know much more then this at this point.

Will use external injectors and return lines. The benefits to this are obvious, a lesser known benefit would be no more fuel in the oil problems from leaking return line seals. Also the injectors, valve covers and fuel lines will be redesigned to accomodate change, I imagine the head will have to be reworked slightly.

The addition of new DTC's.
DTC p0670--generic glow plug code, would trip when system failed.
DTC 671-678--glow plug individual codes, corrosponding code with cyl, (P0604 would be no 4 cyl) They will also be controlled individually like the CA trucks, Total emissions are said to be better then CA trucks currently.

The ecm will use 3 connectors instead of current 2. Not sure why on this

The fuel junction block will be eliminated. Its the part of the fuel system where the fuel rail pressure sensor is located, and the pressure relieve valve is located. It also serves to direct fluid to each common rail. The pressure sensor will be relocated to one rail and the relieve valve will be relocated to the other. This should help eliminate plumbing and leak points. I assume they will still have some type of splitter but not sure what at this point.

I could not get a straight answer regarding power upgrades but simply got the comment that Ford wont stay on top with numbers.

I also recieved a bit of information on the Alli's but I will post that in drivetrain's

Hope this helps shed some light on things to come :D

[kbrowns]

DmaxalliTech,

thanks for the info. I've been wondering about the changes. The redesign to external injectors was the one that I was hoping they would do. The possible power upgrade doesn't sound bad either :D Not sure about the EGR and CAT! Do you know if the changes will be in effect on all '04's or will it be only later build models. I'm beginning to look for a truck, come on stock market(go up PLEASE!)

[Kennedy]

Word is, that it will be a '04.5 release for the upgrades. Looking like March-May from what I hear...

I'm sure that they will have all (or nothing) upgrades in 2004, as in, when the changes come, a vehicle will either have them or not...

[OC_DMAX]

dmaxalliTech,

Good post. For your info, the EGR system currently implemented on my California 2002 DMAX makes the passenger side of the engine really "busy" (translate to cluttered). I would not want to be the tech who has to replace an injector on that side of the engine in my truck (nor would I want to pay for the labor!!). In additional to all the stuff currently there on the 49 state trucks, for California there are four vacuum solenoids(?) mounted immediately above the fuel filter with at least 6 vacuum lines plus supporting electrical wiring running across the passenger valve cover. The exhaust gas cooler is adjacent to the valve cover and the two coolant lines run over/near the valve cover. It would be real time consuming to take everything apart to get too the injectors; heaven forbid ever getting it back together again!! (at least with the documentation supplied in the GM/Helm service manuals). I have contemplated putting in a post-OEM fuel filter, but it is next to impossible to route any fuel lines in this mess of EGR/control stuff (the only hope would be to bend/rotate the filter head input/output metal fuel tubes, not sure if that is possible).

It will be interesting to see how GM mounts the external injectors on the valve covers. On CA DMAX's with EGR emmissions, there is absolutely no additional room for an injector to protrude much above the passenger valve cover. I hope for everyones sake, they spend some time cleaning-up/redesigning this mess. If they do, then the external replacement of the injectors should lower costs to both GM and the consumer.

I'll be interested to hear about the Allison changes also,

Alan

[dmaxalliTech]

JK, I am not sure on a time frame, I was just told 04 model. As soon as we get one in, probably late summer, I will peek and update.

I have never seen a CA truck, but I have heard that they are very bust under the hood, I imagine a great deal of redesign will take place to accomodate egr system and external injectors

I seen a truck that had a remote mounted oem filter in it. It made changes much easier. Simply took the two bolts attatching filter head and remounted. I assume wires for WIF and heater had to be extended, didnt get a good look at it.

[77TransAm]

Last I heard, the LLY was still slated to go into production in January 2004, so anyone taking delivery of a new truck before February or March will still get an LB7 engine.

Some additional thoughts on dmaxalliTech's info: the heads and valve covers are different to accomodate the injectors and lines on the outside, the new glow plug DTCs are because the glow plugs can be controlled individually instead of as a group, and the PCM uses three connectors because it is a new smaller component with a completely different design than the current PCM.

Power is slated to remain the same for 6-speed trucks, but automatic-equipped trucks are supposed to increase a bit... look for something in the neighborhood of 310/565. Ford does get to stay on top until 2006, though... :(

[hoot]

I think if GM/Isuzu keeps reliability no.1, they are doing the right thing by holding the power numbers at reasonable levels.

[Kennedy]

The electronic EGR should help the access as it is much more compact.

It could well be fed from the turbo exhaust casting as well vs. the turbo feed pipe on current units. No solenoids, vacuum lines etc, all built into one. If Isuzu REALLY wanted to get into compact, the EGR valve could also do the throttle plate function as well...