mxs 625 help anyone?

Hi guys new to the forum been reading a lot of the threads but haven't found anything like my problem that I have going on. I recently bought an 05 625 4 axle pete and all I do is run around as a 13 axle. With that being said my truck runs great on short pulls and flat ground but on long grades and I have to drop gears it acts like it is starveing for fuel and only running on half the cylinders for a bit and the boost doesn't boost very high. Then all of the sudden it will slam back to full power and take off doing its thing. Anyone ever have a problem like this. Also was thinking about getting with Richard at antrim and replaceing my stick twins with his twins anyone know how that might work out. Thanks for any help in advance.

 

Ok will do that. Trying to get into cat to get put on dyno to see if they can duplicate the problem as well told them I'm only running 90 psi on fuel and boost only gets to 55 they said something is not set right that they will fix all that on dyno and I will have them check the throttle positionsensor. Thanks for the tip Robsredford

 

Thanks for the pm and the info Robertsredford. As to avail cat couldn't get it to duplicate so now back to hopeing someone had the same problem as me I forgot to mention that when it does it and I pull over I have a lot of blow by then when it straightens up its like nothing ever happened got me baffled but I am also use to the 3408 and just got rid of my hot 3406b. So any help would greatly be appreciated. Thanks again for any help

 

No factory its suppose to pull 62-65 they fixed that today and fuel pressure is now at 110 thanks to me. But that is stock getting ready to add some goodies once I figure out why it is doing what it is doing. Then time to add some power.

 

Yeah I chatted with Robertsredford on the phone earlier and we thought of that and now I'm going to add a fass system and get bigger fuel lines from the tank forward and reroute some lines for better flow. Thanks for the advice will definently figure it out hopefully sooner than later. Thanks again