I have a 99 Dodge with the Cummins motor in it & have a strange problem I cant figure out.
used to be max boost was 20 lbs. loaded or empty, when you stuck it, it would goto 20 Lbs & sit there.
the injection pump crapped out on me & I replaced it with a Blue Chip pump. the replacement went fine, I had no problems getting the gear off & back on again, it all went pretty smooth. I was VERY carefull making sure that everything was lined up right & that nothing moved. (Im using a Mallory 140 Fuel pump, mounted on the rail for a lift pump)
@ the same time I changed the pump I also put in the Edge "RV Injectors" which if Im not mistaken are the 275 HP injectors. the truck had >100K miles on it & I figured it could not hurt to get a bit more HP.
anywho, I also added @ the same time a Bully Dog "Outlook" to the truck. at the time, for those that dont know, the Outlook was thier newest widget. It does a little timing stuff to it to get a little more power & its adjustable right on the outlook. Boost "problems" occur with power setting @ the "stock", 0% setting. IOW, Im not adding any more fuel with the Outlook
OK, so here is the problem. when I put my foot into it, the boost goes up to 24 Lbs & trips the "over boost" engine code. the Bully Dog is too stupid to do any boost fooling, so it keeps popping the code. SO, I called the guy that made the injection pump & talked with him & he suggested I put in the stock injectors (which I did), & that did not fix it. he then suggested I remove the Bullydog Outlook (which I did) & that did not fix it. so..... the only thing that is different is that it has a new injection pump in it. He sent me one of his "old school" Boost Fooling dongles, which is nothing more than a diode that clamps the MAP sensor signal @ 18 Lbs. the problem is that it does not work. I dunno why, but it still see's 24 Lbs & right on que the stupid thing trips the code.
SO............ my problem is not that the boost is too high, Im OK with that. In fact I would like to push it up to close to 30 Lbs, the problem is that every time the ECM see's boost higher than 20 Lbs it trips the code & starts taking out fuel.
I even bought a new MAP sensor thinking that the one I had in it was bad/wrong. but its the same.
well after thinking about the problem a little bit I came up with this solution. I figured seeings how I cant clamp the output voltage of the pressure transducer (the Dongle I have does not work) I figured the easy way around this is to limit the pressure to the transducer.
I bought a simple pressure regulator & a few fittings (the tricky one was the 14mm x 1.5 Male & Female). In short the regulator goes inbetween the intake manifold & the pressure transducer. no matter how high the pressure goes the output of the regulator is fixed @ 20 psi, anywhere below the setupoint of the regulator & the output pressure follows it pretty darn well.
Yea I know it looks like I cut it with a sawzall, but I was in kind of a rush & thats some thick steel to cut with snips on such a short radius. I will make a nicer bracket, later, I want to test it some more & make sure thats its really happy. I drove it around quite a bit today to get it adjusted in & it sits right @ 20 Lbs no matter what the boost is above that. below it, it tracks perfectly (thats why the additional fitting & gauge (not in picture)).
Front
Back
Mounted
SO, my question is. does anyone see a problem with this solution?? Ive been driving it around a bit & dont seem to have any problems. the bost shown on the outlook is right @ 20 Lbs (confirmed with an independent gauge). the computer seems happy (its not tripped any codes) & the manifold boost gauge does show 24 Lbs.
Bob
PS, sorry for the long post, I figured I would put it all in there up front rather than having to answer 100 questions. LOL
used to be max boost was 20 lbs. loaded or empty, when you stuck it, it would goto 20 Lbs & sit there.
the injection pump crapped out on me & I replaced it with a Blue Chip pump. the replacement went fine, I had no problems getting the gear off & back on again, it all went pretty smooth. I was VERY carefull making sure that everything was lined up right & that nothing moved. (Im using a Mallory 140 Fuel pump, mounted on the rail for a lift pump)
@ the same time I changed the pump I also put in the Edge "RV Injectors" which if Im not mistaken are the 275 HP injectors. the truck had >100K miles on it & I figured it could not hurt to get a bit more HP.
anywho, I also added @ the same time a Bully Dog "Outlook" to the truck. at the time, for those that dont know, the Outlook was thier newest widget. It does a little timing stuff to it to get a little more power & its adjustable right on the outlook. Boost "problems" occur with power setting @ the "stock", 0% setting. IOW, Im not adding any more fuel with the Outlook
OK, so here is the problem. when I put my foot into it, the boost goes up to 24 Lbs & trips the "over boost" engine code. the Bully Dog is too stupid to do any boost fooling, so it keeps popping the code. SO, I called the guy that made the injection pump & talked with him & he suggested I put in the stock injectors (which I did), & that did not fix it. he then suggested I remove the Bullydog Outlook (which I did) & that did not fix it. so..... the only thing that is different is that it has a new injection pump in it. He sent me one of his "old school" Boost Fooling dongles, which is nothing more than a diode that clamps the MAP sensor signal @ 18 Lbs. the problem is that it does not work. I dunno why, but it still see's 24 Lbs & right on que the stupid thing trips the code.
SO............ my problem is not that the boost is too high, Im OK with that. In fact I would like to push it up to close to 30 Lbs, the problem is that every time the ECM see's boost higher than 20 Lbs it trips the code & starts taking out fuel.
I even bought a new MAP sensor thinking that the one I had in it was bad/wrong. but its the same.
well after thinking about the problem a little bit I came up with this solution. I figured seeings how I cant clamp the output voltage of the pressure transducer (the Dongle I have does not work) I figured the easy way around this is to limit the pressure to the transducer.
I bought a simple pressure regulator & a few fittings (the tricky one was the 14mm x 1.5 Male & Female). In short the regulator goes inbetween the intake manifold & the pressure transducer. no matter how high the pressure goes the output of the regulator is fixed @ 20 psi, anywhere below the setupoint of the regulator & the output pressure follows it pretty darn well.
Yea I know it looks like I cut it with a sawzall, but I was in kind of a rush & thats some thick steel to cut with snips on such a short radius. I will make a nicer bracket, later, I want to test it some more & make sure thats its really happy. I drove it around quite a bit today to get it adjusted in & it sits right @ 20 Lbs no matter what the boost is above that. below it, it tracks perfectly (thats why the additional fitting & gauge (not in picture)).
Front
Back
Mounted
SO, my question is. does anyone see a problem with this solution?? Ive been driving it around a bit & dont seem to have any problems. the bost shown on the outlook is right @ 20 Lbs (confirmed with an independent gauge). the computer seems happy (its not tripped any codes) & the manifold boost gauge does show 24 Lbs.
Bob
PS, sorry for the long post, I figured I would put it all in there up front rather than having to answer 100 questions. LOL
