V8 Throttle Cable Slack

[jansammut]

Apologies for not posting this in the technical section. My permissions don't seem to allow me to post there. 

 

I've just picked up my esprit, and am having trouble with excess throttle cable slack (enough for the cable to pop out of the pedal side cable eye). I've read the other previous topics on this issue and as I'm 3k kms from home have no tools on me. Is there anyway I can take up the slack from the engine side (as I am unable to take out the seats)?

I read about the black plastic linkage being adjustable, however I can see how this can take up all that slack without fouling the bottom of the plenum or actuating the throttle body (see pics).

I'm at a bit of a loss here, so any help would be much appreciated. 

[stugilmour]

Not sure what the previous topics might have said; sounds like they suggest adjusting the cable or improving the cable anchoring behind the carpet next to the seat?

On my car I had slack at the pedal because of bending of the tang on the pedal (the thing the cable end engages to).  I bent the tang back forward with large water pump pliers.  You may be able to bend the tang with the pliers in your tool kit, or just buy a large set as shown below.

The tang requires strengthening to prevent it from bending back, but it should be good enough to get you back home. Here is a thread with some pictures of a more permanent fix. I did this fix without removing the seat.

http://www.lotustalk.com/forums/f164/mmmm-so-damn-sexy-66658/

Not sure if this is your issue, but perhaps check your throttle pedal to the picture in the thread.  This is apparently a common problem on the V8.  Mine got so bad that the turbo's were not engaging and the pedal was sticking because of the tang rubbing on the carpet.  I simply bent the tang back forward enough to remove the cable slack at the pedal.  The amount of cable slack at the footwell was about what you show in your picture.  I did not have to adjust anything at the engine end or behind the carpet.  

With the re-enforcement method outlined in the other thread the problem has not re-occured, although I would notice the tang bending backward after a few days of use without the fix.  I think I saw one guy re-enforced the pedal by welding as an alternative.

HTH

Stu

[jansammut]

The tang seems to be pretty straight.. Then again I have nothing to compare it to... Does the below look very far out to you?

Edited December 4, 2015 by jansammut

[stugilmour]

Looks bent to me, but agree the picture angles can be deceiving.  The tang should have a very definite forward angle when viewed from the side, and I can't see this in your second picture.  Not sure what the two bolt heads? are on your tang?  Has it already been re-enforced I wonder?

 

I just noticed another clue in your first photo of the pedal.  Looks like the tang end is dragging through the carpet.  This indicates bending has brought the tang too close to the tunnel.  With the permanent fix installed the retaining nut in the end of ready rod is fastened on the outside of the tang where the cable attaches.  Even with the nut and a bit of threaded rod protruding it still does not drag in the carpet.  Yours looks close to jamming on the carpet, which I would describe as somewhat memorable.

I guess the best comparison would be to approximate the distance from the carpet to the cable mount on the tang with the pedal resting on the floor stop.  Or to measure the forward distance from the accelerator pedal face to the cable mount on the tang on a correctly working example?  Unfortunately I don't have my car here at home to take a picture for you or make the comparison; maybe someone else can.  Your stop bolt looks like it may have been 'adjusted' though, maybe as an attempt to get more travel due to tang bending?

I will look around for other threads outlining the tang fix to see if there are better photo's.  This is the thread that had more info on the permanent fix. You can see the forward tang angle indicated / approximated in the various drawings.

http://www.lotustalk.com/forums/f164/sticky-gas-pedal-62951/

http://www.lotustalk.com/forums/f164/check-your-throttle-pedal-cable-how-make-permanent-113506/

Here are a few pictures of a removed pedal box I saved from a recent eBay listing for comparison.  I would consider these to represent the minimum forward angle. I think one can see where this tang has been bent in the past.  I saved the other pictures for reference when installing my cruise control, so they are not my car.

Another point; you can always bend the tang back if you find a different issue when you  get 'back to base'. 

HTH

Stu

[jansammut]

Now that I know what I'm looking at its obvious that the tang is both bent and has been reinforced in the past (metal plate held by the two bolts noted above). 

The plate is not fixed to the pedal arm, so the tang has bent at the base as well at the eyelet. 

I've done my best to sort it out with a set of pliars from the hotel, however I noticed that the weld holding the tang to the arm started breaking so I'm going to hold off the brute force until I get home. 

Is removing the accelerator pedal an Ordeal of Biblical Proportions or is it a fairly straight forward job?

[stugilmour]

Good job!  Caution far from home is wise.  

I believe it is Biblical.  I am assuming the whole pedal box has to come out first.  There is a circlip at the left side of the box (second box picture above).  However, looks like the accelerator pedal would hit the footwell wall before the shaft could be pulled out of the box.   I had the clutch master cylinder done and was told it was pretty much a pain, but i don't think it required box removal.

You may be able to re-enforce sufficiently with the ready rod / carabinier fix, as I don't think there is much force on the weld when all buttoned up.  I think my weld showed a bit of strain and I was a bit concerned, but no issues since the fix.

 

Stu

[jansammut]

Got back home fine late last night, however I doubt I'm getting more than 50% throttle, so fixing the tang is Job #1. Could someone be kind enough to give me a carpet to front to cable eyelet measurement? Or should I simply bend until all slack is taken up when the pedal is floored?

I'll head down to the ironmonger after work to find a J bolt or threaded rod that I can bend to fit after work.

Thanks again!  

 

 

[jansammut]

Also - An idea of what size J bolt works best would be great. 

I guess there's a tradeoff between rod diameter and strength at play here. 

[stugilmour]

I would recommend just bending the tang to eliminate most all of the slack so it is not effecting idle.  The cable should not be hanging loose, but not completely taut.  Once the tang is adjusted and working, adjust the pedal stop bolt so that the cable is not putting excessive force on the linkage, particularly at wide open throttle. The pedal should bottom out on the stop. You may need a helper to get it right.  I think what I did is retained the linkage / bellcrank at the engine open and then adjusted the pedal stop to keep the cable taut.  The brown carpet picture looks acceptably taut.

I did not have access to the Esprit V8 OBDII software when I did the job, but I understand you can use the software to check for wide open throttle (WOT).  I didn't do this part, but I think the parameter you use is Throttle Position Sensor % (TPS%) on the OBD Data tab.  Mine worked out OK as I don't think anyone had tried to adjust the issue out before.  Looking at your photo's it appears you may need to check throttle opening as clearly 'someone has been in there'.

I can't recall the size of carabiner (or 'quick link' in Home Depot language) I used. . 

http://www.homedepot.com/s/quick+links?NCNI-5

I bought some in sizes 1/8", 3/16", and 1/4" and selected the one that fit best; might have been 3/16" but I can't recall.  Pretty sure 1/4" was way too big. The sizing issue is getting the carabiner hook large enough to fit securely around the throttle pedal while keeping the rod diameter small enough to not overly weaken the tang when it is drilled.  I figure 1/8" or smaller rod will have sufficient strength for the fix to work ans it largely relies on the rod being put in tension to prevent tang bending; really more about what you can find to hand.

I found the threads used in the carabiner closing nut to be an unusual size, so it was a bit of fiddling to get the rod and the cut carabiner attached.  You may have to cut the 'biner and then select the matching ready rod.  It seams we might get slightly different carabiners in Canada or Home Depot found a different supplier?  Not a big deal to work around.  Also note one end of the closure is left hand thread, which becomes the hook end.

I considered just using threaded ready rod to make a one piece J hook by bending the rod.  However, it is difficult to fashion to the correct length and install, as you have to simultaneously place the hook over the pedal, feed the threaded ready rod through a small hole in the tang, and then install & tighten a Nyloc nut on the back of the tang.  It requires several attempts to size so the threaded rod and Nyloc doesn't contact the carpet.  The suggested method looks a bit strange, but actually works OK to install in such an awkward position.  I figured once I got the carabiner and rod sized correctly and installed, I could remove the assembly and use it as a template to fabricate something in one piece, but I found it worked OK as outlined.

I also considered using a turnbuckle, but couldn't find one small enough.  I figured something like this would work if I could find it locally.  Would replace the ring end with #8-32 ready rod and a Nyloc for attachment to the tang (hoping it isn't the left hand thread end).  Then bend hook as required to attach to the throttle pedal.  The left and right hand threads in the turnbuckle would potentially make installation easier as long as the whole deal wasn't too wide. 

https://www.fastenal.com/products/details/43302?r=~|categoryl1:%22601922%20Lifting%20and%20Rigging%22|~%20~|categoryl2:%22601938%20Rigging%20Hooks%20and%20Attachments%22|~%20~|categoryl3:%22601952%20Turnbuckles%22|~%20~|sattr01:^5pound8$|~

A few ideas.  I actually sounds more difficult a fix than it is; just somewhat awkward.

HTH

Stu

PS Nice cars!  Where are you located?

[stugilmour]

Had another thought regarding using a turnbuckle.  The RC model car world has a selection of small diameter turnbuckles that might have some promise.  With a bit of fiddling on the attachments at each end they may make a very elegant fix,,,

http://www3.towerhobbies.com/cgi-bin/wti0095p?FVPROFIL=&FVSEARCH=%3Cb%3Eturnbuckle%3C%2Fb%3Es

https://www.hobbytown.com/search.aspx?searchtext=turnbuckle&refine=

These sets look promising; not sure but was trying to find one with metal ends rather than plastic.  

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXKV8&P=ML

https://www.hobbytown.com/Shop/TRA7138X-Traxxas-7138X-Aluminum-Toelnks-w-Rod-Ends-Red-4pc-1-16-E-Revo/

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXKYC7&P=ML

https://www.hobbytown.com/Shop/TRA5338R-Traxxas-5338R-Tubes-Lightweight-Aluminum-Red-Turnbuckle-Revo/

https://www.hobbytown.com/Shop/DUB300-Du-Bro-1-4-Scale-Turnbuckles/

Stu

[jansammut]

I just removed the old support, it's flaw was that it was not welded to the pedal arm, meaning that with time it rotated as the tang bent. I've bent the tang back in place, however it's pretty mangled and weakened by repeated flexing. I reckon the next time the car can be used is on the way to have this fixed. Seeing as it's already been fabricated I'm going to try find someone to tig this to the pedal. Failing that I'll go for the above J bolt solution - Can you just confirm if the bolt used is a J bolt like this: http://goo.gl/eR4zZr  or a complete carabiner like the ones on the page you linked to above?

Also - doesn't the whole thing rotate around the arm allowing the tang to bend again? 

Re: The cars, thanks! I'm from Malta, but currently based in Gibraltar, the cars are spread between both. Living away from home (and my decently equipped garage) makes the car thing exponentially harder as I have no support network here.

 

 

[jansammut]

Ah - now I open that thread on my laptop and I see the post with the instructions - funny, some of the page wasn't rendering on my phone.

 

Looks like a J bolt will work fine.

[stugilmour]

Interesting point regarding the J bolt.  That should work fine.  I must have missed that idea when I was looking at the issue, so I cut the carabiner.  Or i had trouble finding the required threaded rod and coupling nut.

Good luck with the fix.

Spain and Malta  sounds pretty good with snow still hanging around here.

Stu