Engine/Transmission (1994 - 1998) Dad just bought a 12 valve, help me out with order of BOMBs...

[Jeepmullet]

My dad just got a 98 12 valve auto with 4. 10's. I'm educating myself about 12 valve BOMBs, but help me out here. He lives on a ranch and has his own small business doing lawn work and landscaping. He routinely pulls a 5k lb trailer. Will a 4 plate, governer springs, BHAF, exhaust and transmission upgrade do the deal for him? He's not going to do the transmission until it blows up on him, so in the meantime should the BHAF and exhaust be the first BOMB?



What's a decent setting for a diesel rookie (him) for the star wheel?

 

[Matthug]

Absolute first thing is maintenance on a used vehicle. Belts/hoses inspected and fluids all changed.

Gauges next, boost and pyro atleast. Since it's an auto I would also get trans temp.

Exhaust and intake next.

Starwheel cranked all the way up, no harm there. A 4 plate will probably be too much for pulling a trailor, EGT's will be high unless you get a turbo upgrade. I'd go with a 8 plate, 3k GSK, AFC kit. Or if you look into it, do a search on a custom ground stock plate known as the 100 plate I hear it's pretty nice with the 3k GSK. AFC kit will make driveability with fuel mods better, you can get it from piers or TST.

 

[wcjp]

Don't forget replace the soft fuel lines that can/will dryrot causing hard start. Fuel preheater filter. KDP Larry B's starter contact upgrade

 

[Jeepmullet]

Don't forget replace the soft fuel lines that can/will dryrot causing hard start. Fuel preheater filter. KDP Larry B's starter contact upgrade

Where are the soft fuel lines you speak of? the KDP has been tabbed. This engine has 500 miles on it, just newly rebuilt

 

[wcjp]

The supply/return fuel lines will leak air into the system but not fuel out of the system. The lift pump soft line should also be replaced. I recommend using Coast Guard approved diesel line. It's double the thickness of standard automotive diesel line. One of the soft lines runs on top of the transmission. Removing the driveshaft and starter makes access alot easier. Since the starter is already out it's a great time to replace the starter contacts.

 

[McLaughlin]

I'm not sure you really NEED to do a lot of mods to pull a 5K trailer. My 97 only has a new exhaust, 3k gov springs, exhaust manifold, and new air cleaner and I just got done pulling a 4 to 4. 5K trailer between Colo Spgs and Pheonix(gears are 3. 5s?). Maintained 70+ the whole way except on Raton Pass and up the hill to Flagstaff from Pheonix (got down to 65 there). EGTs maxed at less then 1. 2K.



Matt pretty well nailed the sequence in his reply but I'd suggest a transmission temp gauge and EGT first if you only go with two gauges. For what it is worth, it is really as easy to put in all three gauges as once as two and the overall cost won't be tremendously more.



As you have probably read the trannys in the 2nd gen are pretty well known for being a problem. If the transmission is still in good shape, you may want to install a quality torque converter and possibly a quality transmission valve body, right away(if the tranmission is already suspect then I probably wouldn't put either in it). From what I understand, many of the transmission failures are caused by the stock torque converters self destructing or leaking valve bodies and taking out the transmission so putting in a quality torque converter and valve body might extend the life the transmission for quite a while.



Regarding the supply/return lines, if you have problems with the truck, those lines can be right in the middle of alot of the symptoms. If they aren't good it appears they can really lead you astray and cause you to replace parts that aren't bad. If you get into starting, smoking, or fuel economy problems they are something that should be looked at.



Something else to consider is to install a summit wiring harness. That will help protect the headlight switch and provided better lighting at minimal cost($50).



You might also want to look at how much the truck wanders if any. If it does then look at a DSS or 3rd Gen trackbar mod.



If he is in the truck a lot, then you might want to look at putting belsteins shocks on it also.



A spray in bed liner is awful nice also.



I really didn't seem much performance improvement after installing a 4in exhaust so I wouldn't make that really high on the list of mods. If I did it again it would be well after the gauges, wiring harness, and transmission work.

 

[jtwcummins]

First thing is to get gauges. EGT, Boost, and transmission temp. I ran these for over a year before doing anything else. The transmission gets very hot in traffic/idling in gear. Having the gauges will also let you watch the effects of mods.



Second is get the auto transmission serviced at a good dealer while waiting for the gauges. Proper service can keep the trans alive a long time. It helps trans to add one bottle, red one, of lube guard trans additive. It reduces TC shudder under heavy loads. My transmission made it 9 years, 4 yrs since the power pack and exhaust brake install. Do not let the engine lug when towing, try to keep engine rpm at about 2k. You can tow with OD on just turn off as soon as rpm drops below 2k. Lugging makes trans run hot and want to slip.



Next get good air flow. The K&N drop in doesn't get the job done. Get AFE or other BHAF. The Banks Twin Ram works great on the 12V but is pricey, I gained 30 HP. Put on a good 4" exhaust. What you will see on the gauges is totally stock the EGT will go to 1200-1250 under load, moving more air effectively will drop the max EGT to just under 1100 for same load. The engine runs quieter on the road when lots of air flows thru the system.



Last, add a plate or more fuel by moving factory plate forward and doing some tweaks to the gov and add 3K GSK kit. The GSK makes the defueling start at a higher rpm and makes day to day driving better and you should add this after getting the air flow.



How far to go adding more fuel depends on the power the driver wants. The gov tweaks like the AFC, moving stock plate forward, and the 3k GSK might make it the truck your dad can enjoy driving and aren't high priced bombs.



AS a note, check the trans cooling lines at the trans cooler and make sure they aren't the ones with plastic clips. If so get the replacements with steel clips from the dealer or change the line connections to any good style. The plastic clips have been known to blow under load, aka towing, and cause trans to drain on the road and burn up.

 

[tURBOdIEZEl]

the fuel heater relays have a tendency to short out and cause air to get in the fuel lines..... you might want to get the timing advanced to 16 or 17" advanced. that will help out with mileage.

 

[jtwcummins]

Oh yeah, forgot the timing as mentioned. Had mine set to 15. 5*, can do without other 'bombs. It helps economy slightly and take off alot.

 

[Jeepmullet]

Does timing mean star wheel? What is pump timing, and how is it different?

 

[Forrest Nearing]

star wheel loosens the tension on the AFC which allows the fuel to come in earlier... with less boost... spools the turbo up quicker and can put out a little smoke if it's too loose



pump timing = injection event timing... it's SORTA like ignition timing on a gasser because the injection event is essentially the ignition event on a diesel

 

[RDelissen]

the way I went on mine is pretty much summed up above:

BHAF and straight pipe first (breathing and exhaling easy)

Pyro, Boost, transmission temp gauges (know what the engine is doing and how the transmission responds)

3k GSK was an absolute must on mine with 265 tires and 4. 10 gears



Now the next mod is going to be a Goerend transmission (and then a fuel plate and then ... :-laf ).



But so far I can't complain about the ability to pull and that GSK really made the difference

 

[Jeepmullet]

star wheel loosens the tension on the AFC which allows the fuel to come in earlier... with less boost... spools the turbo up quicker and can put out a little smoke if it's too loose



pump timing = injection event timing... it's SORTA like ignition timing on a gasser because the injection event is essentially the ignition event on a diesel

Thanks,



What does it mean to turn the timing up to 15 or 16 degrees then? Is that turning the timing up on the p7100 (I sorta tried to read and understand the piers FAQ on the P7100). I guess my question is: Is turning up the pump timing what people mean by turning the timing up to 15 or so degrees?