Throttle issues

[Criox]

Hello Everyone
I have some weird issues with my throttle and I was just wondering if anyone had or have the same.

When adding some throttle really gently, the rpm on tachometer drops and comes up after second or two.
Its frustrating usually when starting from lights or roundabouts as there's no reaction for a while and I have to push the gas pedal stronger to avoid choking the engine.
Its more noticeable on 1'st gear as the car jerks more ( but present on all gears ).
Yesterday I tried to press the gas pedal on neutral and I choked the engine completely ( using gas pedal only ).

All filters replaced and didn't resolved the issue.

The worst thing is that its random. I can do 500miles and this doesn't occur. Then its present for 10 min to be gone again for a while.

I tried 2 mechanics, one of them tried to replace fuel filter, second whats to clean EGR.

The engine is 2.0 HDI on Citroen C5

I would be appreciated for any clues what this might be. Fuel pump, electrics...or maybe pedal itself.

Regards

[Hell Razor5543]

Well, I would suggest that, before you spend any more money on the car, get a Lexia onto her, to see what codes there may be (as well as to see live data from when the engine is running). Generic code readers will not be much help here, but there are forum members who are willing to help out, and have Lexia equipment. Here is the link;

https://www.frenchcarforum.co.uk/forum/ ... 19&t=29178

[Criox]

My mechanic tried one code reader, it gave him: Unknown error lol
Thank you for help

[myglaren]

Sounds like it could be burned or dirty tracks on the throttle pot.

[Criox]

Right... My wee C5 has no error codes ( checked 2 days ago ).
The worst thing is that this is so random. I can do miles and its perfect, then it comes back for few minutes drive me mad.

Thanks for any help

[Criox]

We checked the Car with proper gear and codes that I have are.
AIAH / 2586 - Unknown Code
D40IH / 54273 Unknown Code

That this mean anything to anyone ?
Thank you

[Hell Razor5543]

If the code reader was not a Lexia it is unlikely to get a meaningful reading from the car. The PSA group did not follow the industry standards for quite a while.

[Criox]

Thanks Hell Razor
Tried few code readers, some didnt show anything, the latest gave me this. Thought its finally something
A trip to dealer will be a good idea then.

[Hell Razor5543]

A dealership may well charge you £50 for a diagnostics session. Before you go there, check out the following link to see if there are any Forum members near you with a Lexia, and are willing to help. There are two in Northern Ireland (there is a map link near to the bottom of the list);

https://www.frenchcarforum.co.uk/forum/ ... 19&t=56452

[Criox]

I visited dealership twice.
No one in the area to help me with reading codes btw.
There are no error codes present, visually everything is ok for them.
They took a car for a test drive but they couldn't reproduce the issues mentioned.
So before replacing half of the engine parts that gave some probability of causing this issue I can use a reading from a glass ball or fortune-teller at this point.

[KennyW]

As previously mentioned get it checked by a lexia then the correct PSA code/s will be flagged up.

Kenny

[Criox]

So the only option is to buy it myself.
I thought dealership has them, are they not?

Cheers

[ekjdm14]

Strange that the dealer didn't find anything, although if it's something like the throttle pedal potentiometer that's acting up but staying within operating parameters then it may not throw a code, and as it's intermittent it would only show on live data if/when it actually glitched...

I would suggest either try and get it on lexia when the fault is appearing, or if there's any way of recording live data that would be the way to go. (I'm not sure if Lexia allows for any sort of remote data-logging/recording but if you can catch it when it happens that'd be the ticket IMO...) Intermittent stuff like this is often hard to track down without data from when the fault actually occurs...

Personally, if I was in your situation I'd get a used Throttle pot. from either a scrapyard or ebay and try that as you'd be able to get one for less than the price of a dealer diagnostic session (and if that didn't cure it, you could always resell on the 'bay, so not a huge risk IMO) Just had a quick root & 2.0hdi TPS seem to be going for about 15-20 quid on ebay, I'd suggest a scrapyard would want about a fiver for one you removed yourself.

Just make sure the part number is the same as the "outgoing" item... You may well find one on Peugeots using the 2.0 HDi motor (and possibly, according to some info, Fiat 2.0 JTD models too)

[Criox]

Thank you ekjdm14
Will try and go this route
One query though... is that throttle pot. would cause killing the engine on neutral?
As I was able to choke the engine using gas pedal

[Old-Guy]

Drove a Transit last week with a very similar fault: stutters on a light throttle between 1800 and 2300 rpm. Asked for my opinion by my friend in the trade, I reckoned it was a tired throttle sensor (potentiometer). "My thought's exactly. The d******* has replaced the EGR valve twice in a may weeks! Reckons they must be from a dud batch. Makes you want to weep."
It's a 'fly-by-wire' system with no physical connection between pedal and engine; the throttle sensor (pot.) is designed to give the engine ECU a 'throttle position' signal, but an iffy throttle pot is like a driver with a nervous twitch in the right foot, the message isn't getting from brain to engine!