Jump to content
Sign in to follow this  
hpgtowing

Low On Power

Recommended Posts

Got a 1981 Mack Heavy spec. single axle Mack Wrecker.. big 29,000 Rear.. with a homes 850 Wrecker back... Maxi Torque 5 speed with a 4 speed Brownlipe aux. .. Truck weight is about 35 to 36,000 LBS.... iT HAS A 285 TIP TURBINE MOTOR... The truck has about 160,000 miles.... The motor was inframed just before I bought it.. about 2 years ago... I had the injection pump gone over, adjusted the valves... but the truck just is lazy.. no torque and down on power..... Any ideas? Thanks

Share this post


Link to post
Share on other sites

check the throttle linkage to see if its slipped a few teeth on the shaft going into the pump.

have had a simmilar problem on a company truck before, this was the reason?

Trent

Share this post


Link to post
Share on other sites

Thanks Trent.. It's worth a look for sure.... Thanks.. Steve

Share this post


Link to post
Share on other sites

is the truck smoking black when pulling? :SMOKIE-LFT: because if you don't see any smoke look on the intake manifold forthe little piston, when he's game over truck won't smoke because it cut the fuel to the pump...

Share this post


Link to post
Share on other sites

Steve ,check the puff limiter, unhook it see if it runs better, even if is working right if you unhook it it will run better Ron

Share this post


Link to post
Share on other sites

I'll check the puff eliminator today.. I didn't even think of that... Thanks..Steve

Share this post


Link to post
Share on other sites

Ron I disconnected the puff eliminator... Yeah it did run better... Considerably when up in a hiher gear.. You could now feel the truck wanna pull... it's still a bit lazy... I'm gonna replace the spring check valve (T-shaped Valve) at the injection pump... I'm told these weaken after a while and tend to reduce fuel pressure slightly.... I'll keep you posted... Steve

Share this post


Link to post
Share on other sites

I have the puff limiter on a air switch mounted on the dash. bob tailing I notice an increase in accelaration from a dead stop or low rpm. when the truck is loaded it just feels the same. check your Fuel press if its good check your fuel feed lines from the tank. sometimes rust can collect in the lines or air from a crack will hinder flow to the pump.

Trent

Share this post


Link to post
Share on other sites

Steve you might take the short fuel lines to the filters off and see if you can look through them , i have had them where they look good on the outside but closed on the inside , like trent said you might check all the fuel lines, i have a 76 285hp with a 5 speed 3.87 rears ,it will run with a 350hp cummins with 90000 lbs + pulls good Ron

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...