Ok guys, I have a 12v street truck build that has taken a few interesting turns. My setup is 58 over 71 compounds, 215 pump with 22* advanced timing, full cut delivery valves, 5x14 injectors. plus supporting mods. still on stock mechanical lift pump.I dynoed 561/1089 with this setup and it obviously had more if I got it some more lift pressure. Shortly after that I crcked my 53 block and switched to another truck. Same setup with a few more improvements, improved the stock mechanical lift pump, oringed and ported exhaust side of head, and advanced timing to 24* except now it is making 100hp less with better fuel pressure. Egt topped out at 1300 on the dyno and there was some smoke at wot, but not a lot. The only other difference is in the old truck I would see 75-80psi of boost and now I am only able to see 35-40 tops. I assumed my gauge was broken or the truck wouldn't load up as much because it is much lighter than the old truck. I [pressure tested the intake side and didnt find any boost leaks. Please help!
Lost power help!
- Thread starter rust2race
- Start date
95cummins5.9
Old man ***** gossiper
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- Jun 18, 2012
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Check your timing buddy.is the fuel shutoff lever all the way up? Verify fuel pressure? Afc line no leaks. Run a boost test
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Yes solenoid pulls level all the way up. Fuel pressure on the 561hp run got way too low, bottomed out at <5psi. Since I improved my lift pump now I have 18-20psi at wot with 475hp. the hp curve doesn't drop as fast at higher rpm, but the peak is much lower.
95cummins5.9
Old man ***** gossiper
- Joined
- Jun 18, 2012
- Messages
- 4,721
Take a look at the diaphragm in the afc also. Make sure the afc is slid full forward. Is the woodruff key on the shaft for the shutoff solenoid?
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Redrider2911
New member
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What about the transmission? No slippage? If your torque converter isn't as tight, it might not load the engine enough to turn the turbos.
Trans is brand new fully built with all billet shafts and triple disc converter. 175psi of line pressure in OD locked. No slipping issues at all.
I'm out of town and away from my truck for a few days, I'll check this out when I get back. Thanks guys!