Chrisreyn

ok, I recently had a tighter torque convertor installed( an RV-HD one), and am pleased with how it drives empty, but am still getting sub-par mileage ( 16mpg) and upon towing the trailer for the first time today, was disappointed in the lack of power! From the start of the hwy on-ramp, it took almost 5 miles on level road to get up to 65mph! at 70mph, I was dropping speed going up slight hills.. and fuel mileage dropped to around 10mpg..

I cant afford the 200 bucks for a pyro right now, so what can I safely do to the pump or elsewise to increase the power?
I am gonna bump timing up 1/8 as soon as I can find a wrench for that bottom bolt, but what else would help?

BTW the trailer was a 20 foot gooseneck with two QH's, so probably around 7000lbs total weight.... shouldnt have noticed it back there.......

wannadiesel

Sounds like it's running pretty weak. Have you checked to be sure you are getting full throttle lever travel at the pump? Also make sure the boost line to the AFC housing is intact, and remove the AFC cover and fuel pin so you can check to make sure the little guide pin pops out when the throttle is cycled. It's likely one of these problems making the truck so weak.

If you do have to resort to pump tampering: Do not touch the power screw. Turn the fuel pin so the deep side faces the rear, and shave the plastic washer as need to get full travel. Leave the star wheel alone unless there is excessive smoke on take-off, back it out a couple turns is the truck smokes until the turbo spools. What we don't want is a situation where you get a lot of fuel before the turbo spools, with a trailer on the back that will make things really toasty.

Timing should bring your mileage around. Is that 16 mpg figure for local driving or out on the highway? 16 mpg was the best mine would do in local driving, big injectors have dropped that to 14.5.

Chrisreyn

I havent checked anything yet.. the 16 mpg is combined hwy/city.( my normal commute is 10 miles@ 70mph,4@65, then 5 more at 40 with 5 stoplights that I may or may not hit..

The pump was rebuilt as part of the deal when i bought the truck last June, and I am not too sure of how it was set..the cap was off the AFC housing when I got it.

It doenst make smoke at all, not at WOT pulling up hill , and barely hazes when cold started, so i am thinking its not getting the fuel it should be.
I dont really want a lot of smoke( stains the horse trailers)...I think I may call John over at Floor-It and see when he would have time to go over the pump and settings with me..

wannadiesel

You ought to be getting at least 18 mpg under those conditions.

Sounds like when the pump was reinstalled the timing wasn't set right, and also the rebuild was set up weak - but check that stuff I told you about before you spend money having somebody "turn it up" for you.

Chrisreyn

will do Dave..........Thanks!

mikmaze

take a ride to Downingtown PA and drive home with the biggest smile you ever had...... Dave could set you straight in no time. too far to drive I guess but if you can find someone that understands the truck and what wanna said, follow his advice and let the truck be tuned.as for the gauge, pop in the classifieds here often and you just might fing a good deal.

SkinnyBTN

There is a Pyro/Boost gauge for 75 right now in the 1st gen high performance section. It would at least be a good safety/bargain till u get what ya want. I'm not selling it by the way. Just some friendly FYI.

Chrisreyn

OK, If I am making NO smoke at all, even under full throttle and a load, is it safe to turn it in until I just get a light haze? Right now, i get a puff of light grey when first started, but nothing after that....
I am missing the upper nut holding the pump to the timing case.. the one closest to the KSB is tight, and so is the bottom one as far as I can tell...I tried getting at it today with a 1/4 ratchet and wobble -socket, and I think I could loosen it, but I am not sure if I could tighten it back up , so I left it alone.. timing still isn't advanced any.

I filled up after i got all these changes done, I 'll post in a few days if they helped or not..
Thanks for the advise Dave!!

wannadiesel

Just to verify: with an assistant in the cab flooring the pedal you get full travel?

Just because you can hand cycle the linkage under the hood does not mean you are getting full travel when you step on it.

While you're messing around with linkage, back the high speed limit screw all the way out and adjust the linkage for full travel. Swapping the return spring and ball stud is the easiest way.

I would not mess with the power screw blind on a tow rig.