Detroit 12.7 DDEC 4 Interesting problem

@smellfunny. Blown intake gasket? I don't really think so. Reason being is that with my doing the ECM work moved the boost psi up 10 psi. It's still acting the same, just doing it at a higher boost psi. Very hard to explain.

 

Just throwing things out there that could cause loss of pressure. The last head I took off a Detroit the guy's intake gasket was blown in half on the back set.

 

If the borg warner larger than the garret you replaced it with it maybe causing some lag? Also I was under the impression that the series 60 in near stock form would perform better with a wastegated turbo seeing as it should spool up quicker. I think the non-wastegated turbo is more beneficial after some added mods like a ported manifold and a hotter ecm tune where the engine would be pushing more air through it. Maybe call out Cowpie for some advice on this I believe he has a pretty hot setup on his series 60.

 

yeah it would show all codes as normal. i used the ddec iv trouble shooting guide and it would allways refer to change ecm or the sensors that i had just changed even witt the dddl everything check out normal after changing ecms ,new and known working sensors truck would still be iffy.

 

This is a little premature to post probably, but I just ran an overhead on my truck. Valves are all fine. But the injector height was off almost 3mm on all injectors. I reset them all to 81 mm like the specs call for. Just wondering if anyone knows how the injector height being that far off would affect the motor.? Will start and run it. A little later and update.

 

You've changed air and fuel filters right? One of the first signs my fuel filters need changing is not getting full boost. I have a 99 DDEC4 430/470 engine. I get 32+ boost on my gauge.

 

Ok guys, got the old girl back on the road. Pulls good. Real good. But still only ever see 28 psi of boost. Crazy. Yes, I changed all the fuel filters. Air filters. With the tune I have in the ECM, I ought to be hitting 40 psi without any problem. I don't really want the boost to go that high, but I set the tune that high to see if it would change the boost pressure. Somebody mentioned the intake gasket. I guess I'll check that yet. Is there a way to check that without just removing the intake manifold?

 

40psi of boost on a Detroit? How much rpm are u getting

 

How about the hose going from the intake manifold to air compressor?

 

If it's a boost leak you should hear it. It could be an intake gasket or compressor hose but again you should hear it. The way I check them is pull the air filter wrap it up in heavy plastic to seal off the open end and put it back in. Put 8 to 10 pounds of pressure in the intake at the 1/4 in pipe plug. Then spray everything from intake to air filter. This way it checks to see if your sucking unclean air while checking the entire intake system for pressure leaks not just the air to air cooler.

Just shooting from the hip I would say check the baro/atmospheric pressure harness and sensor. I have seen no codes and still cause the just not fueling feeling. Also check the cam timing. That will effect boost and power. It does usually cause high EGT temps though.