Hdi high idle

[Steve1990]

Hope someone can shed some light on my high idle issue my car idles between 950 to 1100 most of the time but if your driving down the road and i depress the clutch and take my foot of the revs the car will idle anywere from 1100 to 2000 rpm untill i come to a stop then the idle will drop to just over 1000rpm. Ive checked the throttle cable and it goes all to way back ive also checked the wiring loom for broken/brittle wires and all is fine my next thoughts are with this fuel pressure regulator just wondering if anyone else has experienced anything like this and what it could possibly be as its driving me mad thanks.

[bashbarnard]

Has the car recently been mapped? have you done any work recently? The only real things that can cause this would be a didgey connection on the throttle position sensor or the sensor itself. Even if it has a massive air leak it wouldnt be much else as its injection duration that makes it idle. Have you had it plugged in to check that the tps is readin the correct amount through its full sweep??

[Steve1990]

The car is mapped but its been mapped for nearly 2 years ive not done anywork recently either I haven't had it plugged in either tbh. Is it more or less a definite no on the fpr? I cant understand why it idles high when going down road with clutch down but as soon as i come to a stop it goes down alot thinking about it it doesn't do it as bad when the car is warm.

[Magenta Sunset]

i'd prob look at TPS 1st too.

[Steve1990]

Think I'll nip up scrap yard then just to rule it out

[bashbarnard]

like i said smash it on diag and check through the sweep first to see its working ok. The fpr may cause an issue but ive never seen one. both of which though you can check readings on diag which is why we have the ecus.

[Ruan]

Would bet on FPR if it's fluctuating around - bet it's jamming.

A 306 should always idle at 820-850rpm (900rpm when vehicle is rolling) as long as the coolant temperature is more than 20*C depending on amount of time after the engine was started, the idle should be rock steady unless the injectors or FPR is faulty.

The idle speed setpoint changes when the vehicle begins to roll which is why you see the change - if the FPR is faulty, it'll move and jam, causing the uncontrolled increase in engine speed.

[bashbarnard]

interesting, ive known faults on other cars with fprs but never these. seems a bit odd to be honest. shame i just threw one out really on a rail you couldve had it. I also have diag here if you need it as well. near bury st edmunds suffolk.

[Ruan]

interesting, ive known faults on other cars with fprs but never these. seems a bit odd to be honest. shame i just threw one out really on a rail you couldve had it. I also have diag here if you need it as well. near bury st edmunds suffolk.

FPR isn't on the rail on these, it's in the pump. That would be a FPS

[bashbarnard]

interesting, ive known faults on other cars with fprs but never these. seems a bit odd to be honest. shame i just threw one out really on a rail you couldve had it. I also have diag here if you need it as well. near bury st edmunds suffolk.

FPR isn't on the rail on these, it's in the pump. That would be a FPS

f*ck me im really not paying attention anymore. I hold my hands up, i am wrong. Of course it is now you say it, held in with a little torx bugger on the side. Fail

[Steve1990]

Thanks for the reply been busy with work going to take it out at weekend it is possible to just soak them in acetone or something simlar to clean them rather than replace them isn't it? I bought the seal kit for it last week hoping that just cleaning it would work. Oh and the car does fluctuate sometimes when sat in traffic but it doesn't do it as bad as it used to.

[Steve1990]

Just wanted to follow this up i took fpr out and removed the seals gave it good soak in acetone and the idling problem is a little better that it was but is still there. My next question is when i took the fpr out there was no micro filter on the end I didn't loose it because i was so careful when taking it out and had a white blanket just under the injection pump so i could see anything if something did drop out of the pump has anyone else seen them without the micro filter or would this suggest someone's been in here before.

[JTaylor2005]

Mine never had the micro filter on it when I removed it and I am pretty damn sure it had never been removed before. I believe some where built with them and some without them. Earlier ones were without I think.

[Uberderv]

Yup I've had them with and without. How's bout doing an injector leak off test to see how they are doing.

[Steve1990]

Ahhh never thought of they they are a bit rattley bit then again from what if seen most injectors are on these. Think ill give that ago next the cars currently in bits as I decided to start my wheel bearing late afternoon think ive got a spare set of injectors incase these a f*cked.

[madmadmax]

i got a set or two of injectors in sheffield if you need some for testing

[Steve1990]

Thanks madmadmax but ive now sorted the issue just wanted to post a final post to say the throttle potentiometer was at fault the car now idles as it should just wanted to post this as i know how frustrating it is when researching faults and you read every single post but there is no answer to the problem.

[Welshy_Pete]

My old 306 hdi the tick over idle was running lumpy. So I check the tsp throttle position sensor tapping the side of the round part that moves around. I could hear the spring inside rattle meaning the spring had weaken.

I put another on and it was fine and the spring never rattled inside either.

[DeeTurbo]

Did you get this fixed?

Just thinking could it be the clutch switch that at fault?

Sent from my ONEPLUS A3003 using Tapatalk

[TommiePuglet]

My old 306 hdi the tick over idle was running lumpy. So I check the tsp throttle position sensor tapping the side of the round part that moves around. I could hear the spring inside rattle meaning the spring had weaken.

I put another on and it was fine and the spring never rattled inside either.

Sorry to jack the thread.

Are these a hard thing to swap mine has a lumpy/bouncing idol.

[DeeTurbo]

My old 306 hdi the tick over idle was running lumpy. So I check the tsp throttle position sensor tapping the side of the round part that moves around. I could hear the spring inside rattle meaning the spring had weaken.

I put another on and it was fine and the spring never rattled inside either.

Sorry to jack the thread.

Are these a hard thing to swap mine has a lumpy/bouncing idol.

Do a injector leak off test as it might be a dodgy injector and it's easy to do to confirm.

Sent from my ONEPLUS A3003 using Tapatalk

[Welshy_Pete]

My old 306 hdi the tick over idle was running lumpy. So I check the tsp throttle position sensor tapping the side of the round part that moves around. I could hear the spring inside rattle meaning the spring had weaken.

I put another on and it was fine and the spring never rattled inside either.

Sorry to jack the thread.

Are these a hard thing to swap mine has a lumpy/bouncing idol.
[/quote]
There easy to change over 10min job

Sent from my GT-I9505 using Tapatalk