HELP! Engine drops to 25% pwr!
Post Fiend
Joined: Feb 2007
Posts: 7,191
Likes: 4
From: Blairsville,Ga
Originally Posted by ernesteugene
I'll make it as clear as I possibly can, this is my last attempt. With the TC locked you have in effect a solid shaft between the engine and the rear wheels. If you turn the input end of a shaft one turn and the output end doesn't go one turn, I'd say the shafts broke or slipping. 65=2000 for a 4.10 diff and stock tires, 71=2000 for a 3.73 diff!
think 2000 RPM in direct is bout 47 mph
Last edited by rbaker6336; Jun 23, 2007 at 11:07 AM.
Postmaster
Joined: Jun 2006
Posts: 2,647
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From: Fulltime RVer
Originally Posted by rbaker6336
if it hasn't downshifted can only be slippage for sure
think 2000 RPM in direct is bout 47 mph
think 2000 RPM in direct is bout 47 mph
Post Fiend
Joined: Feb 2007
Posts: 7,191
Likes: 4
From: Blairsville,Ga
I had some what similar problem on last loaded trip
for some reason was watching guages boost 18 lb speed and rpm started dropping boost stayed same then down shifted speed same rpm up boost dumped as I topped hill
started down hill boost came back to 10lb shortly after power came back
next time came to 18lb same thing
finally decided new map sensor was defueling at 18 lb boost,put old one back on everthing fine since
for some reason was watching guages boost 18 lb speed and rpm started dropping boost stayed same then down shifted speed same rpm up boost dumped as I topped hill
started down hill boost came back to 10lb shortly after power came back
next time came to 18lb same thing
finally decided new map sensor was defueling at 18 lb boost,put old one back on everthing fine since
Junior User
Joined: Jun 2003
Posts: 70
Likes: 0
From: Highlands Ranch, CO
Does it sound like its "missing"? Is it hard to keep it running at idle? If it dies, does it not start for awhile, then miraculasly starts running fine and you think everything is OK?
If that is the case, then it sounds like the wiring harness that feeds your injectors. It is a long-standing problem with these 7.3L that the connection to the wiring harness works its way loose until the connection is not satisfactory. Unfortunately, the connection is under the valve cover on each side. If you search for this on this site you should find a lot of repairs for this. The first time this happened, I pulled the valve cover, pinched the connection back and thought "There is no way that was the problem." Put it back together and it was fixed. A year later it happened again and I made a spacer to hold the connection tighter. This time it lasted two years. Guess what I was working on before I came on line? I have not come up with a permanent solution.
If that is the case, then it sounds like the wiring harness that feeds your injectors. It is a long-standing problem with these 7.3L that the connection to the wiring harness works its way loose until the connection is not satisfactory. Unfortunately, the connection is under the valve cover on each side. If you search for this on this site you should find a lot of repairs for this. The first time this happened, I pulled the valve cover, pinched the connection back and thought "There is no way that was the problem." Put it back together and it was fixed. A year later it happened again and I made a spacer to hold the connection tighter. This time it lasted two years. Guess what I was working on before I came on line? I have not come up with a permanent solution.
