So I recently got the fever and decided to do the efan mod and underdrive pulleys.


Here's the basic info on my ride.

05 f150 fx4 5.4 v
Air force 1 3.5 in intake
scal2 with troyer tunes
Efan flexalite controller and 17"proform fan


I've had the efan setup for about two weeks with no problem and some decent improvements to the trucks performance. (for those of you thinking about it......do it, just make sure you spend the money on a good digital controller!)

Now I just ordered a set of ASP UD pulleys, which came in Friday.

Was a typical install. No problems, but I now when I stomp on the gas it's sluggish until about 3K then it comes alive. The engine sounds like it's sucking air.....but only running on 5 cylinders, until that 3K then I get all 8.

I thought maybe the efan coming on was pulling the power down or causing some wierd backfeed to the computer. So i disconnected the efan.

Still had the problem. Put the stock pulleys back on and the efan. NO problems. Runs like a bad@#$

Put the UD pulleys back on after thinking maybe I had a lil wobble on the crank pulley causing the knock sensors to freak out. Or maybe I just pulled a bonehead move or something.

After the 2nd install runs much better, but I still need to put it through it's paces. I think the reinstall may have cured it.....but even if the 2nd install works I wanna understand what caused the problem to occur.

Anyone have any thoughts on this.

 

Maybe not enough juice from the alternator? Depending on the level of charge for your battery at the time, maybe it's weak and the alternator can't keep up with the smaller pulley until you get it to the normal rpm for it. Just a thought.

 

Hmmm ... I had the opposite experience - felt a noticeable improvement across the rev range with TP UD's.

The install torque and seating is crucial for sure - you do know that the crak bolt is torque-to-yield, right? a fresh one is recomended each time.

Did you bump up the idle with yer X2 afterwards as recommended by TP?

Not much else comes to mind - what you are describing is very odd....

We need a guru - Paging Jbrew ...

MGD

 

I've had a similar issue. But I have the stock fan and stock pulleys. You can see my mods in my sig. Mine started with custom tunes. Never had a problem with just the edge, intake and exhaust, but when I had my edge converted to a gryphon with custom tunes, the problem showed it's face. It would randomly decide to drop a cylinder or two. I've tried installing new filters, new plugs and COP's thinking I might have a weak COP of a fouled plug, clogged fuel filter or something, but that was not the cure. The problem has reduced in frequency, but is still there. It feels and runs like it's dropped into the "limp home mode" or the overheat mode that the 5.4 has. 99% of the time it's fine, I've just been living with the other 1%. One thing I've noticed is it tends to happen when running by the O2 sensor (part throttle), but then if you slam it to the floor so it ignores the O2 and runs off the fuel tables, the problem goes away...maybe time to try new O2's...

 

Thanks for the thoughts guys.

I did bump my idle before the install to the recommended spd. forgot to mention that. I actual have more volt than before so I think I'm ok.

mgdfan-expand a little on your comment about torque to yield and why the install torque is critical. I'd be lying if I didn't get the new pulley seated and then zipped the bolt on the lowest setting of my impact. Kinda figured everything would seat down on the crankshaft.

Like I mentioned in the first post, once I did the reinstall. - AWESOME. Not that I can beat a stang or camaro. But I can now break the tires loose on DRY pavement. (couldn't do it before)

And just for those of us that are data driven. Here's food for thought.

Old pulley weight 10.1 lbs
New underdrive pulley from ASP 5.7 lbs.
Mech fan weight-8.3 lbs.
That's some serious weight reduction on the crank.

 

https://www.f150online.com/forums/v8...rank-bolt.html

https://www.f150online.com/forums/v8...questions.html


MGD

 

Thanks for the enlightenment MGD. I'd buy you a BUd light if you were a fan

 

Hello, I have basically the same set-up and have notice the same problem the last couple of weeks. When under light throttle till about 2000rpms truck bogs then runs fine after that. Keep getting a po340 code also. Have changed sensor but didnt' fix. Just wondering if you fixed yours with the change of the underdrive pulleys.

Thanks

 

what is the torque rating for the bolt then?

 

ASP install procedure:


"Auto Specialties recommends that these pulleys be installed by a qualified mechanic. - Obligatory CYA Boilerplate


1. Loosen water pump bolts.

2. Remove belt. Tensioner is accessible from under truck. CAUTION: Insure truck is properly secured on jack stands before accessing underside of truck.

3. With transmission in first gear and emergency brake applied, remove harmonic balancer bolt. An impact wrench will be required with automatic transmission. Remove harmonic balancer using a 3 prong balancer remover. Remove water pump pulley.

4. Apply high temperature silicone sealer to underdrive harmonic balancer keyway. Install harmonic balancer onto shaft. Use 12mm x 60mm bolt to engage harmonic balancer on shaft only far enough to engage factory bolt then remove.
CAUTION: Do not tighten 12mm x 60mm bolt as damage to threads may occur.

Torque factory bolt as follows:
1.) Torque to 75 lb/ft.
2.) Back out 1 turn
3.) Torque to 45 lb/ft and then tighten an additional 1/4 turn.

5. Install new water pump pulley and factory belt. Insure belt is seated properly in all pulleys. Tighten water pump bolts. (NOTE: on the 1999 -03 5.4 trucks, there is an aluminum nipple sticking out from block. It is located at the bottom right hand corner near waterpump. You have to grind this off in order to get the water pump pulley to fit.)

6. Start engine. Inspect all pulleys to insure no wobble and that belt is properly installed. "

MGD