Odd misfire/throttle problem.

[Bristol182]

Hi,

I have done a lot of searching and reading and have found many similar threads, but none seem to have all the same symptoms so I hope it's ok for me to start a new thread?!

I have a problem with throttle inputs being largely ineffective along with a misfire. Unfortunately my problem is compounded by a dud lambda, I have a new lambda on order which should be here tomorrow, so hopefully after changing that tomorrow it will make this throttle fault easier to track down.
Anyway, this throttle problem is intermittent, I started the car up just now and it ran and idled fine for 20 mins, I was able to rev it up as expected and the throttle pedal seemed fine (note: it only revved up to 3k but I believe that is due to the lambda fault putting it in limp mode).
After I had run it for 20 mins I turned it off and started it up again straight away and this time is was running terribly, if I left it to idle it would sound like it was misfiring and would soon idle so low that it stalled, if I pressed the throttle not much would happen, on WOT it would rev up to about 1200rpm or a little higher but that was all. Very odd as literally minutes before it was running and idling smoothly (apart from having a 3k rpm limit due to lambda fault).
It has been on a diagnostic machine, I don't know what machine though as it wasn't mine (I don't have any renault diagnostics stuff). The throttle fault showed up as '257' but an internet search doesn't come up with anything relating to it that I can see. You can also see the lambda fault in the pic:

So far I have changed the throttle pedal, removed and cleaned all the fuses/relays from the fuse box in the engine bay, cleaned up the white connector in the fuse box and removed and cleaned the throttle body. All of which were quite clean anyway, but none have made any difference so far.

What should I try next?

 

[banther]

@bloke @Scrooge

 

[bloke]

'IF' all your connectors etc are good then you're looking for a wiring issue, time to get the meter out. i'd also sort the misfire before you swap the lambda, had lambda fault come up quite often but only due to a misfire.

 

[Bristol182]

'IF' all your connectors etc are good then you're looking for a wiring issue, time to get the meter out. i'd also sort the misfire before you swap the lambda, had lambda fault come up quite often but only due to a misfire.

Are there any other connectors I should be checking apart form those already mentioned?
I noticed when removing the TB that the connector for the TB has had all the wired to it cut and replaced just near the plug, as if someone has put a new plug on. It looks to have been done properly though, all soldered and shrink wrapped. Should I remove the shrink wrap and check each of the connections?
I have a multimeter to check the wires, but tbh I wouldn't know what to check for, is there a wiring diagram anywhere that I could try and follow?

p.s. I don't have any renault diagnostics stuff, so if I manage to fix the problem will the limp mode etc go away by itself or can I remove the battery to reset it?

 

[Bristol182]

Also just thought, is it worth me changing the throttle body? When the idle is jumping around and it sounds like it is misfiring there is a very fast clicking noise from the throttle body.

 

[Scrooge]

Limp mode will go away once the issue is resolved.

Got anyone local to you you can swap you TB with for a check?

I've not had an issue with a TB in ages, wiring on the other hand I have.

 

[Bristol182]

I don't know anyone with a clio, I'm new to the scene! Is there a function for searching this forum by location to find anyone local to me?

I agree it is most likely the wiring, I just thought as swapping a TB is so easy it might be worth trying to eliminate it?

I will get a pic up of the soldered wiring to the TB, it must be an issue that someone has tried to fix before. I wouldn't know where to start with checking the wiring, would I be best off getting a replacement loom (about £40 on ebay) and just swapping it out?

 

[Bristol182]

I got a photo of the wiring to the TB, it seems to have been done properly with shrink wrap so not sure if I should fiddle with it or not.

I also got a video of the sound coming from the TB after the engine has stalled itself. In this video the engine is NOT running, all that noise is coming from the TB. If the ignition is turned on it does not make this noise, it only makes this noise once the engine has stalled itself (and the ignition is still on).
http://vid256.photobucket.com/albums/hh195/geekfreakenator/clio/20160203_170731_001.mp4

 

[Bristol182]

Anyone? Particularly interested if anyone has viewed the video in my last post and can offer any advice as to the odd noise? Do they 'all do that'?

 

[Bristol182]

I bit the bullet and got a replacement (used) throttle body and it seems to have sorted the problem. It now starts and runs fine without cutting out, it also idles properly and revs up as it should when I press the throttle. Also it no longer seems to be in limp mode, even though I haven't changed the lambda yet, but the engine light is still on. Hopefully that will go once I have the lambda changed.