53mph is now 40mph top speed

[50shooter]

Hi guys.

Long story short. Truck ran on the way home from the pickup at 53mph. Truck quit a few days later...bad fuel , filters etc? Truck runs great now having cleaned the tank new fuel, new fuel filters (all 3). It does run great only slow as the top speed is now 40mph at 1,600 RPM.

Fuel filter flow rate issue? I used the Napa ones everyone on here recommended so I doubt this is the problem.

I've read several threads and most lead to some adjustment related changes. I didn't touch the IP or anything.

Ideas please.

Thanks

 

[WillWagner]

Make sure it's getting full throttle and the shut off cable is all the way in.

 

[buccaneer]

1600 rpm

Can you get more than 1600 rpms when shifting through the gears accelerating?

(scratching head)

 

[FreightTrain]

have you checked your air filter or the little hicky under the steering wheel(filter condition meter).

 

[SasquatchSanta]

Check to see if the in-tank fuel pump is running. You should be able to hear it before you start the engine --- with the switch on.

These trucks will run (assuming you can get them started) with the in-tank pump not working but they won't "always" run like they should. It's something to check.

Good luck.

 

[cranetruck]

I second Will's suggestion above, check the foot pedal movement and linkage.

 

[jasonjc]

Is the truck empty or do you have a load on it?

 

[mistaken1]

Go download and read the LDS 465 Troubleshooting Manual. It is a wealth of information and it should address your issue.

http://old.steelsoldiers.com/index.php?module=pagesetter&type=file&func=get&tid=1&fid=file&pid=57

 

[cbvet]

I wonder if you dislodged some debris that is now obstructing fuel flow?
If your in-tank pump is working, turn on battery switch. Open petcock on primary fuel filter & see if you get a good flow .
If yes, then open up secondary filters & check for flow.
Etc.

Eric
CBVET

 

[50shooter]

Thanks a lot for the replies guys. My internet went down shortly after the initial post and I've been chomping for some pointers.

The shut off cable is in but I will verify under the hood.
I do get full RPM in neutral and the other 4 gears
I checked the air cleaner indicator and double checked the air cleaner
The truck is empty (except the 1,000 gl water tank that is empty)
I may have dislodged some crud in the process but am hoping the filters are shagging most of that and the truck runs great in all other gears.

I can't verify the throttle linkage but I will when able. The pedal seems to freely move all the way.

Thanks
Jason

 

[Matt1970M35A]

My truck did the same thing after I got it. I thought I had turned up the fuel rate on the ip but just lurned I had turned it down. Suonds odd but it worked. I was still not happy with it changed the air and fuel filters. It did not help. only till I lemped home I found I missed a filter
Their is a primery filter on the right side of the frame rail. It looks like the one on the engine.
I would check it out. Also if the filter is made of a hard rock like stuff you can clean it.
I also noticed that my ip made a wineing sound. Mine got so bad that the bypass valve was opening and made the engine sound like it had a bad miss.

Let us know what you find.