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Discussion Starter · #1 ·
Title says it all. My 1988 Super Duty has a low mileage wrecking yard engine in it with 40k miles. It starts and revs up just fine. Problem is that I am getting closer to 5 MPG and nowhere close to 10 MPG. It also is doggy without much spunk and the exhaust smells really rich. It stinks bad and the fumes will burn your eyes. The only mods I have made are to ditch the Cad converter, replace the single muffler with a huge free flowing one designed for a motorhome, advance the spark 2 degrees, and remove the venturi thingy in the plastic air intake that is right before the injector body. The truck has a manual 5 spd trans. What is wrong with this thing?

Dumpster
 

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Make sure there is vacuum to the fuel pressure regulator and that it is functioning properly. 33 idle with vac. 43 ish no vac.
Another possibility is the MAP sensor. Check vac line from manifold to the sensor.

Initial advance with SPOUT DISCONNECTED should be minimum of 10 and max of 14.




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Discussion Starter · #4 ·
No vitals but it looked factory new when I bought it a number of years ago. I can check but I have no reason to suspect it is mechanically unsound. I will pull a couple of plugs and snoop around a little. It always starts right up and then idles down after going rupp rupp rupp a couple of times when cold and running rich.
 

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Time to do the chain and gears, actually with the retarded cams these have it was time for this little bit of rebuild from day 1!
The 88 to end of production EFI engines utilize a straight up double roller timing set.

Cam specs are essentially the same for passenger car and truck engines

193 / 206 @ .050"

113 LSA

110 ICL when straight up
118 ICL when retarded crank gear is used. 1972 to 1987 carb engines.





Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
 

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Discussion Starter · #7 ·
What would be a good replacement cam for this application? Once again it is a 1988 F450 Super Duty with factory port injection. It has a 12' hydraulic dump bed and I use it to haul dirt and gravel mostly. So, at times the load will be up to 2 ton maybe more. When up to speed it hums along nicely but bottom end seems to be a bit lacking. I have found that revving it up before shifting helps as otherwise gear changes are doggy. And the gas mileage is very poor.

What specs would be good for a new cam and chain set? Something that has some low-down grunt but still allows higher speed performance.
 

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Delta is local and grinds all of our cams.
You would need to take the cam to delta and have it plotted on their Cam Dr. Performance trends analyzer.

There should be a part number on the back face of the rear journal.

Did you address the issues in my prior post?

Cam timing would need to stay short given the application.

What cam is currently in the engine? Proper straight up timing set like OEM?





Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
 

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Discussion Starter · #10 ·
Stock factory cam is in motor now. Not sure what "cam timing short" or "straight up" means. Was it still common after 1988 to have a retarded cam in a factory motor? I don't remember the year of the motor in the truck now, but it was from a much newer truck. Thanks for the info on the cam number and Delta.
 

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Stock factory cam is in motor now. Not sure what "cam timing short" or "straight up" means. Was it still common after 1988 to have a retarded cam in a factory motor? I don't remember the year of the motor in the truck now, but it was from a much newer truck. Thanks for the info on the cam number and Delta.

As I noted in post #6 ALL EFI 460 engines used straight up / not retarded 8 degrees cam timing with an HD double roller timing set.

For a work engine short cam timing means keep duration smallish or short.





Scotty J. "AKA" The "Mad Porter"
"EMC 2006" 3rd place finisher
Ported BBF iron head specialist & Aluminum heads from all sources.
Custom ground cams
See our products in the Vendor for sale section
Customized crate engines
ParklandAutoMachine.com
R-H-P.biz
"Parkland Performance Auto Machine" Formerly RHP
(253)-988-6648
Parkland Auto Machine
 
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