metermatch
Registered User
I have some questions about my 166hp 7.3 IDI diesel: Low power and low MPG.
What is the difference between my 1990 166hp 7.3 IDI and all the other 7.3 NA diesels that are rated at 185hp? Can I cost effectively make mine 185hp?
I need more power between 1600 rpm and 2300 rpm.
I’m realistic and would be happy with 10%-20% more power and 1-2 mpg improvement at 1600-2300 rpm. I don’t think I want to go the turbo route, as spending $2000 plus a new pump and a bunch of time isn’t worth it on a $4000 truck,
Questions:
1) I have heard ? that the power difference between 166hp and 185hp motors is in the injector pump. Is it smog related, as this is a California truck? If I got a Baby Moose pump, and the recommended injectors, would that make it a 185hp motor? Would advancing timing to 9 degrees also help at that time? Would I get the power boost I am looking for? At 125k original miles, perhaps a new pump isn’t out of the question.
2) I have heard that when towing, I should just leave the overdrive on. The problem is the truck cannot pull the load on anything other than flat land, so I spend most of the time in 3rd gear, and shifting to 2nd on hills. Would a gear change to 4:56 be a good idea to get the rpms higher so I can effectively have a 4 speed trans instead of a 3 speed trans?
Truck is California 1990 F350 dually extended cab 7.3 166hp diesel, 4:10 Sterling 10.25 rear end, E4OD trans, well maintained with 125,000 miles original, Original injection pump, injectors changed by dealer at about 70,000 miles. Tires one size oversize, I believe 235-85/16, and I think I calculated the tires at 4% greater circumferance. Totally stock, clean truck. Truck runs/starts very well. Also, it NEVER smokes. I always read about trucks with black smoke. None from my truck. I believe motor is in very good condition, and burned ½ quart oil in 5500 miles.
Truck has low power, and low MPG. Empty, it gets 13-13.5 Hwy MPG at 60 mph. Towing my 7’x16’ enclosed trailer/5000 pounds and a small 1500 pound cabover camper (about 12,500 pounds total) it got 10.3 mpg to Bonneville Speedway and back (1300 miles) and was so gutless it was dangerous. Foot near floor pretty much the whole time. Many hills in 2nd gear and 35 mph. One hill 1st gear@ 15 mph. This is normal paved US highway around Ely, Nevada.. Normally, I am described as a grandmother when driving, as I usually get better mileage than anyone I know on any vehicle. Same trip/load with near identical 1990 crew cab F350 dually 460 gas engine/E4OD and 500 more pounds get 8-9 mpg and probably 35% more power.
Since that drive, I did make a small change, as I bought a Ferret meter and timed the injector pump from about 3 degrees BTDC to about 6-7 degrees BTDC. I would have gone to the recommended 9 degrees BTDC, but there was a lot of resistance from the fuel lines, and I did not know how to loosen them.
I have an EGT meter, and temps get to a high of 1100 degrees at wide open throttle on long, steep hill. I have replaced the fuel filter and air cleaner.
I dynod the truck yesterday, and it made 129 rwhp at 3200 rpm. Again, this was after advancing the timing to 6-7 degrees BTDC. Probably pretty strong for a 166hp IDI. Guys in the dyno shop were joking that it was a gas motor, as it didn’t have any smoke at full throttle.
Thank you for any ideas,
Jeff
What is the difference between my 1990 166hp 7.3 IDI and all the other 7.3 NA diesels that are rated at 185hp? Can I cost effectively make mine 185hp?
I need more power between 1600 rpm and 2300 rpm.
I’m realistic and would be happy with 10%-20% more power and 1-2 mpg improvement at 1600-2300 rpm. I don’t think I want to go the turbo route, as spending $2000 plus a new pump and a bunch of time isn’t worth it on a $4000 truck,
Questions:
1) I have heard ? that the power difference between 166hp and 185hp motors is in the injector pump. Is it smog related, as this is a California truck? If I got a Baby Moose pump, and the recommended injectors, would that make it a 185hp motor? Would advancing timing to 9 degrees also help at that time? Would I get the power boost I am looking for? At 125k original miles, perhaps a new pump isn’t out of the question.
2) I have heard that when towing, I should just leave the overdrive on. The problem is the truck cannot pull the load on anything other than flat land, so I spend most of the time in 3rd gear, and shifting to 2nd on hills. Would a gear change to 4:56 be a good idea to get the rpms higher so I can effectively have a 4 speed trans instead of a 3 speed trans?
Truck is California 1990 F350 dually extended cab 7.3 166hp diesel, 4:10 Sterling 10.25 rear end, E4OD trans, well maintained with 125,000 miles original, Original injection pump, injectors changed by dealer at about 70,000 miles. Tires one size oversize, I believe 235-85/16, and I think I calculated the tires at 4% greater circumferance. Totally stock, clean truck. Truck runs/starts very well. Also, it NEVER smokes. I always read about trucks with black smoke. None from my truck. I believe motor is in very good condition, and burned ½ quart oil in 5500 miles.
Truck has low power, and low MPG. Empty, it gets 13-13.5 Hwy MPG at 60 mph. Towing my 7’x16’ enclosed trailer/5000 pounds and a small 1500 pound cabover camper (about 12,500 pounds total) it got 10.3 mpg to Bonneville Speedway and back (1300 miles) and was so gutless it was dangerous. Foot near floor pretty much the whole time. Many hills in 2nd gear and 35 mph. One hill 1st gear@ 15 mph. This is normal paved US highway around Ely, Nevada.. Normally, I am described as a grandmother when driving, as I usually get better mileage than anyone I know on any vehicle. Same trip/load with near identical 1990 crew cab F350 dually 460 gas engine/E4OD and 500 more pounds get 8-9 mpg and probably 35% more power.
Since that drive, I did make a small change, as I bought a Ferret meter and timed the injector pump from about 3 degrees BTDC to about 6-7 degrees BTDC. I would have gone to the recommended 9 degrees BTDC, but there was a lot of resistance from the fuel lines, and I did not know how to loosen them.
I have an EGT meter, and temps get to a high of 1100 degrees at wide open throttle on long, steep hill. I have replaced the fuel filter and air cleaner.
I dynod the truck yesterday, and it made 129 rwhp at 3200 rpm. Again, this was after advancing the timing to 6-7 degrees BTDC. Probably pretty strong for a 166hp IDI. Guys in the dyno shop were joking that it was a gas motor, as it didn’t have any smoke at full throttle.
Thank you for any ideas,
Jeff