Engine/Transmission (1994 - 1998) High Egt's, poor performance, please help

[abranz]

Hopefully you guys can help me. I bought a 98 12v with 120,000 miles, stock other than a fuel plate. Well I changed all the fluids, tabbed the dowel pin, and changed leaking seals. Installed a Westach egt/boost gauge and it ran between 800-900 empty and would climb to 1500 going up an onramp full throttle. Then I noticed it had a coolant leak near #6. I changed the head gasket and it leaked again, then I noticed the crack in the head. I bought a new head, had it installed by a diesel pro who also timed it and installed BD RV injectors (mild ones). After all this egt's are still hot. Then I had a original fuel plate installed which seriously decreased power. Max boost is around 25. Now I have a total dog, with poor boost & low power. I've looked at the intercooler boots and none are torn/abraided. I don't no where to turn. I'm looking for a dependable truck with some power to pull loads between 8000-12000 pounds. I would appreciate any suggestions. Thanks, Anthony.

98 12v QC, 4x4, NV4500, 4:10 gear ratio

 

[Rams-n-Hogs]

Have you opened up the exhaust? Maybe the cat is plugged, if it's still on there.

 

[Cooker]

Pressurize the intake system and check for boost leaks.

 

[abranz]

I removed the cat, otherwise the exhaust is stock. Again appreciate any help/suggestions. Anthony

 

[Erniek]

A 4" exhaust (turbo back with flow thru muffler) dropped the egt's on my 97 about 125 degrees, that may help you?? You said you had a shop set the timing, what did they set it to? If they set it to the stock setting, you could have them bump it to 16 degrees, and that should bring your egt's down a bit too. (I wouldn't go more than 16 cause the cylinder pressures go up pretty high for the stock head bolts and gasket) What number plate did you have in before you changed back to the stock?? Did, and does it smoke alot on take off (low boost), and does it smoke at higher rpm's??? 25psi boost sounds right for a stock set up. What was the max boost with the other plate installed?? Is there a boost elbow installed??



Erik

 

[abranz]

Fuel plate was a 12. Timing set less than 16 degrees. Stated he set timing at factory setting. Boost elbow is in place. Hope this helps. Any suggestions?

Thanks Anthony

 

[Rams-n-Hogs]

If there's no boost leak, I would look at adjusting the AFC housing, and starwheel, and check the gov lever adjustment. There shouldn't have been much of a loss between a #12 plate and the stock plate. Do you have any smoke?

 

[KevinH]

sounds normal to me. a 215 pump with a plate and injectors will hit 1500* in a hurry empty at WOT ecspecially with no intake or exhaust and hauling a load. my sugestion would be a 4in exhaust, intake and buy a bigger turbo or get your stock one upgraded.

 

[Graphic man]

take a look at the wastegate and make sure it's not stuck open a little.



Scott

 

[Missouri Mule]

Should of let timing at 16 and you can always put a higher horse power fuel plate back in.