Lumpy idle when cold also longer to start when warm

[Chris_90]

As above ive got lumpy idel when cold and when its warm/hot it takes longer to start than when its cold (dont take ages but takes like 3-4 more turns of the engine) any one no what the problem is??

[Mr Whippy]

Is it standard, or has any mods?

Cheers

Dave

[Chris_90]

a sportex back box and a k&n pannel filter thats it

[Poodle]

How many miles is it on? Sounds like it could be knackered pump and injectors, can't think of anything else that'd cause it...

Not really heard much of these kind of problems with HDi's before. No chance the timing could have slipped?

[Tom]

Coolant temperature sensor?

[Poodle]

Ah, you thinking the ECU could be having trouble whether to run cold-idle or not..?

[Chris_90]

why could it be coolant temp sensor?? its done 156,000, not sure about timeing it had a new timeing belt at 152 thou (before i owned it) but it drives bang on pulls as it should no other problems, the lumpy idle dosent effect it in any way just annoying, and as for the starting it takes like 2-3 turns of the engine to start when cold then when hot would say 5-6 turns over just not sure why dosent really affect it in any way

[cully]

before you crank it turn off and then on again prime the low pressure system
if things improve it may be the low pressure pump on the way out

[Tom]

I had the same problem with a fiesta, and the problem is related to temperature soo what senses temperature

[cully]

MAF senses air temperature on the HDI

[Chris_90]

before you crank it turn off and then on again prime the low pressure system
if things improve it may be the low pressure pump on the way out

Ive done this no differance in starting time......

MAF senses air temperature on the HDI

Could this cause the problem?? i will get a video up asap so you guys can see what i mean i think i may just be, being daft about the warm start takeing a bit longer........

[cully]

i was poking at Tomw as i beleive he was eluding towards the coolant temp sensor

but try unplugging the MAF sensor and give it a go you never know could be the issue

[Chris_90]

Done a video see what you guys think

Cold start with lumpy idle
http://www.youtube.com/watch?v=FiKLD26Og5Q&feature=plcp

Hot start taking longer to start than when its cold (some times take longer maybe a few more turns)
http://www.youtube.com/watch?v=GqXH4KgtgsI&feature=plcp

[cully]

dont think you have a problem with hotstarting sounds ok to me!

[Poodle]

Hot start in that vid only takes one more crank than the cold start...?

See what you mean about the random idle though, never seen that before, not on a 306 at least.

No-one seems to be putting any more theories forward so will have to work with what you've got for now or pay to have it professionally diagnosed.

[Chris_90]

some times takes a couple more turns than that wasnt warmed up to normal temp

[aircool]

Low pressure pump is worth checking (check for fuel leaks in the engine bay)?

Mine did similar although not as bad so I OCD'd and replaced the lift pump straight away

[Daniel306]

I dont know much about Hdi's, but that idle looks fuel related to me

[Poodle]

I'm assuming she's well serviced etc, fuel filter isn't ruined..?

[Chris_90]

I'm assuming she's well serviced etc, fuel filter isn't ruined..?

I changed the fuel filter around a week ago not made any difference it was very dirty tho and needed changing, The lumpy idle doesn't make any difference to the car just annoying if your sat on tick over, if i drive of straight away as soon as ive started it doesn't make any difference to the way it drives......

[Ruan]

Check the coolant temperature sensor...

Yes, the MAF detects the air temperature into the engine, however, there's 3 coolant temperature sensors on a HDi, and there is a map to relate coolant temperature to IQ and SOI IIRC the blue or green one should be the one to the ECU IIRC. Brown is Bitron unit.

It could be sensing wrong and assuming the engine is hot all the time and running more retarded timing, causing the lumpy running.

[Chris_90]

Check the coolant temperature sensor...

Yes, the MAF detects the air temperature into the engine, however, there's 3 coolant temperature sensors on a HDi, and there is a map to relate coolant temperature to IQ and SOI IIRC the blue or green one should be the one to the ECU IIRC. Brown is Bitron unit.

It could be sensing wrong and assuming the engine is hot all the time and running more retarded timing, causing the lumpy running.

Were is it?? is it the one were the thermostat housing is?? if i just unplug it if it sorts the problem then i no it thats??