Fix for Throttle Lag | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Fix for Throttle Lag

JCUZ

Explorer Addict
Joined
September 4, 2007
Messages
1,204
Reaction score
13
City, State
Canberra, Australia
Year, Model & Trim Level
2004 Explorer Limited V8
Hey all. I haven't had my 2004 Explorer very long - about 3 months now, and one thing that annoys me is the throttle lag - which is really a lack of delicate throttle (pedal) control. Having owned a number of fords over the years where the accelerator (gas) pedal is hinged and uses a spring, and knowing the Explorer pedal is not hinged on the accelerator shaft - it is fixed - I thought I'd remove the accelerator assembly from the truck, and have a go at "fixing" it. The results are very, very good, and the cost was nil. Read on if you want to know how I did it:

1. Undo the 3 x 11mm (7/16" ??) nuts that hold the pedal assembly in the truck. Unclip the electrics, and remove complete pedal assembly from the vehicle.

2. The pedal is attached to the shaft using two large "toothed" rivets/pins. I put the assembly in a vice, and using a punch and a hammer, carefully (not really - more like brute strength), knocked/belted out the pins.

3. I then used a 4mm (approx 5/32") bolt and matching nyloc nut, with a washer each side, to hinge the pedal using the bottom holes of the pedal and the shaft (drilled "round" to match the 4mm diameter of the bolt), and also installed a "torsion spring" - the hinge bolt holds the spring in, and I had to drill a small hole in the plastic of the pedal backing and also one in the shaft to hold each end of the torsion spring in place.

The spring I used is like the one at the bottom left of the picture below. Don't laugh, but it actually used to perform duties in a set of BBQ tongs that died last week; it was the rescuing of the spring from the broken tongs that got me thinking about how I could use it for the Explorer pedal. OK, now you may laugh. At some stage, I will go to the local wreckers/car parts recyclers, and source an actual torsion spring used on a Ford accelerator pedal setup.
pr_torsion.jpg


The throttle is now far more sensitive and easier to use. A small amount of pressure on the pedal, now moves the pedal towards the flat (factory) position against the shaft, and the spring in turn forces the shaft to move quite slowly, but the overall effect is that the truck is no longer in a state of either stopped, or moving at full tilt - it now moves off the line quite sedately, and it is actually easier to get it moving. If you want to accelerate hard, then that is also easier to do, as you just apply more pressure to the pedal. I had previously found that to move off quickly required some finesse with your foot and the pedal, as the throttle always seem to be all or nothing. The new arrangement means you just squeeze the pedal, and the spring makes it a more linear progression from stopped to moving. Hard to explain, but if you hate the way the Explorer accelerator works, then this small mod is for you.

I have read of a few different ways to get around the throttle lag on the Explorer, and the most effective ones seem to be by removing find/vanes from the inside of the Throttle Body in the intake - this may result in smoother airflow, but I don't see how it can fix the lag which is actually a result of a poorly designed and executed accelerator pedal. Hinging the pedal and using a spring actually changes (for the better) the way the accelerator pedal works.

If you try this and don't like the way it performs, all you need to do is either put in the original pin in the upper hole in the pedal and shaft, or use a bolt and nyloc nut in those same holes to go back to a "fixed" pedal setup. I doubt you'll go back though.
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





Thanks for posting this information! Do you have any pictures of the actual machining to show a comparison of the way it was before, and after this mod? Did you every have the dealer flash the PCM to give it a new tune in order to correct the throttle lag? I've heard of other people on this site suggest a similar mod, but were afraid to do it because of getting "electrical gremlins". They thought that the PCM would start to display a check engine light, and throw codes. Did you experience anything like this so far? How many miles do you have on this mod?
 






Thanks for posting this information! Do you have any pictures of the actual machining to show a comparison of the way it was before, and after this mod? Did you every have the dealer flash the PCM to give it a new tune in order to correct the throttle lag? I've heard of other people on this site suggest a similar mod, but were afraid to do it because of getting "electrical gremlins". They thought that the PCM would start to display a check engine light, and throw codes. Did you experience anything like this so far? How many miles do you have on this mod?
I didn't get any pictures yet, but will try tomorrow - means I have to remove the assembly again, but the good wife will have the truck out and about. I only just completed the job this evening, and took her for a spin around the block, and noticed the difference immediately. The big test will be tomorrow when the missus is driving - if it passes her scrutiny, then I'll know it works well; she hates it worse than me.

There is no change to the accelerator setup with this mod, apart from the pedal being hinged instead of fixed, so I don't expect any PCM or electrical issues at all; the modification simply allows "finer" throttle control (it's all in the spring).

I just reread your question about the PCM - as far as I know, the truck has the most up to date PCM flash available in Oz. The dealer that services the car has a good reputation for checking and updating the tunes for all models they service - for those with their own flash tuner, this actually causes more headaches for them (but I am not one of those)!
 












There is one thing which I'm curious of. Does your vehicle run on gasoline/petrol or LP gas?

Currently runs on Gasoline (usually E10), but am looking at doing an SVI LPG conversion. Why do you ask?
 






I was once experimenting with propane, and the engine didn't accelerate properly. The computer wasn't designed to use it, and was unable to adjust the mixture properly. It kept backfiring, sputtering, and was unable to rev more than the regular idle speed.
 






JC throttle control

OK, pulled it back out, and got some photos:
Pedal assembly with pedal removed
01-Assembly_Pedal_Removed.jpg


Drill small hole for spring and cut off some of the shaft
02-Spring_Hole.jpg


Trim plastic so spring fits
03-Pedal_Modified.jpg


04-Pedal_Spring_1.jpg


05-Pedal_Spring_2.jpg


06-Pedal_Spring_3.jpg


07-Pedal_Spring_4.jpg


08-Pedal_Spring_5.jpg
 












You didn't tell us. Did it pass the misses approval? :D

Indeed it did. She was quite surprised at how much better it was, actually (I think she though I was exaggerating).

The pics I've posted above include a stronger spring, and after re-installing the assembly and going for a quick spin which included a couple of stop signs, some Give way (Yield) signs, a set of (red) traffic lights, and a few other general turns, it is even better than it was yesterday! I would recommend at least a 3 turn torsion spring, rather than the 2 turn one I had yesterday. I can now "feather" the throttle so much more easily, it's like chalk and cheese. I actually enjoy driving the truck now - well, I enjoyed it before, but I don't have to work so hard on the throttle position to get it to take off "nicely" - the lag is all but gone.
 






I don't see how that helps feather the throttle. I looks like your only adding more flexibility to the pedal head to conform to the users foot. I guess the proof is in the drive:)
 












Are you using a throttle cable now instead of the throttle by wire set up from the factory? I originally thought that this was the whole point of this mod.

The throttle mechanism has not changed at all - so still running fly by wire setup.

muzzymaniac - it is all about "comfort" or control I guess. It's hard to describe what a difference this makes, but already we have noticed a drop in the instant fuel consumption figure of around 1.2 L/100km. This is because we are now able to have the throttle at much lower/less throttle position than was previously possible. The lag when you put your foot down in the Explorer is now gone totally. A small movement of the foot now equates to a small movement in the pedal, where previously, you had to squeeze a bit harder to get more throttle.

Like I said, hard to explain, but for a minimal cost, I would encourage anyone to have a go at this to see what I mean. The difference between before and after is great - my missus actually rang me on the way to work this morning to tell me that it's brilliant with the new heavy gauge spring.
 






Interesting. Please keep us posted. I'd love to know if you see a change in gas mileage.
 






Interesting. Please keep us posted. I'd love to know if you see a change in gas mileage.

Yep, will do. Should know by this time next week what the gas usage was for the week (we only filled again yesterday). The last 3 tanks have averaged 19.11l/100km, and I reckon this modification to the pedal will see it better 18l/100km (I predict somewhere around 17.7l/100km).
 






Damn! I forgot you weren't in the US. Now I have to get out the conversion chart!
 






Im not doubting you at all (because Im no expert here)... but I can't get my head around how adding a pivot to the gas pedal will eliminate the lag around corners and increase fuel economy?
 






Im not doubting you at all (because Im no expert here)... but I can't get my head around how adding a pivot to the gas pedal will eliminate the lag around corners and increase fuel economy?

I understand the doubt - basically I did this in desperation because the lag around corners etc was so frustrating and annoying. My other Ford has a gas pedal that pivots, so I thought, what the heck, may as well try it.

What pivoting the pedal seems to do is allow a slight/medium pressure on the pedal to slightly move the shaft and give small increments of acceleration - it kind of smoothes out the movement a lot, and basically eliminates the "dead spot" in the throttle. I realise it doesn't seem to make sense, but I can tell you that it does actually work - I wouldn't be sharing it otherwise. And it's cheaper than the other options of aftermarket intake pipes, removing vanes from the TB inlet etc - all of which I doubt actually improve the throttle response, because the throttle being the way it is has more to do with the pedal than with the TB end.

The good part is, that if you spend the $3 or so on a spring and a bolt and nut, and you don't find any difference, then all you need to do is put the original pin back in the upper hole of the pedal and it is solid mounted once more; the spring etc will still be there - just rendered inoperative. How many other mods can you reverse for nothing, and the mod only cost $3 (approx) to try!

I also modelled the hinging pedal on a local Ford (known as a Falcon) that uses throttle by wire, so I figured if it's good enough for that car, it's good enough for the Explorer.

For anyone who is unsure about this (ie if it works etc), if you were in Oz, and I did this mod to your truck and it DIDN'T work, then I would wear the cost of parts etc in returning it back to standard - that's how confident I am that it does work, and that it works well.

On the fuel consumption side - I am not guaranteeing that it will provide better consumption, but we have found an improvement as we are using less throttle to get moving off the line - but for a $3 mod, even if it doesn't improve consumption, it's not going to make it worse!
 






Well, we've averaged 17.6 l/100km; that's 16 mpg in the old money. At 19l/100km, we were using 15 mpg. So not a huge increase in economy, but better than nothing. And, yes, we do believe it's due to the better throttle control.
 






Got 17.2 Litres/100km (approx 16.5 mpg) for the last tank travelled! Much better than the 19 (or 15 mpg) we were getting previously
 



Join the Elite Explorers for $20 each year.
Elite Explorer members see no advertisements, no banner ads, no double underlined links,.
Add an avatar, upload photo attachments, and more!
.





One way I improved the throttle response on the '04+ 4.0L V6 was to remove the plastic throttle body spacer. It has some little "teeth" moulded into it that allow a smoother transition from closed to tip-in throttle. Thing is, these vehicles don't need a smoother more gradual transition to tip-in...They need an improvement in such.
By eliminating this little spacer and replacing it with a standard fibre gasket, there's no more restriction at light throttle openings, which equates to a somewhat more responsive feel in the throttle response. It's getting more air quicker when the throttle is opened.

The mod is simple, and should take all of 10 minutes. It's only for the 4.0L V6, not the 4.6L V8...The V8 doen't have the same design.

First, remove the throttle body from the intake plenum, then remove the spacer/gasket. Install (1) Fel-Pro #61050 throttle body gasket* in place of the spacer. Installing the throttle body with the original bolts will require a couple washers on them to make up that difference that the spacer took up. Otherwise, it's possible to bottom out the bolts in the plenum and possibly split it. On mine, I got some new bolts that were about 1/4" (~4mm) shorter to give it a more finished look, but two or three washers on each bolt will accomplish the same thing.


The difference is quite noticeable, especially when rounding a corner and getting back into the throttle, the response is much better. These trannies still don't have the quickest downshifts and sometimes seem to get a bit confused as to what gear to be in, but aside from that, I feel it's a worthwhile mod. I also like the extra little "swoosh" noise when the throttle is just tipped in. It's very noticeable with an aftermarket intake or even a K&N drop-in filter in the stock airbox. With a standard paper filter, it's there, but much more muffled.

Considering you'll have less than $2.00 USD invested in this mod, it's definitely worth a try.

*Order the throttle body gasket for a '99 F150 4.6L if you can't get this exact brand or your parts store requests a vehicle application.
 






Back
Top