Slow to start when warm

[AngusL 10]

Hi Guys,

I have just seen this and i have not seen any mention of the crank sensor. My car was getting harder and harder to start and was a bit inconsistent and odd infrequent cutting out at tickover. I'v had a split air inlet hose and seen the surging revs that that caused...Cleaned the ISV and MAF.. I did some reading in here and concluded that a dodgy crank sensor was a prime candidate. I bought a FIM brand fron ECP 79.99 fitted in minutes once the car was jacked up and the car has never missed a beat since... hot cold it starts first time every time. Hence I have not been on here for a while. I have had this issue since I bough the car a year ago but since I fixed this in Nov 2015 its been a fantastic runner. Note when you remove the old crank sensor there is a collar and seal on it that will probably stay in the hole. Make sure you get this out otherwise the new sensor will not seal and will leak oil. My cars running has been totally transformed

[jamin 0]

Hi Guys,

I have just seen this and i have not seen any mention of the crank sensor. My car was getting harder and harder to start and was a bit inconsistent and odd infrequent cutting out at tickover. I'v had a split air inlet hose and seen the surging revs that that caused...Cleaned the ISV and MAF.. I did some reading in here and concluded that a dodgy crank sensor was a prime candidate. I bought a FIM brand fron ECP 79.99 fitted in minutes once the car was jacked up and the car has never missed a beat since... hot cold it starts first time every time. Hence I have not been on here for a while. I have had this issue since I bough the car a year ago but since I fixed this in Nov 2015 its been a fantastic runner. Note when you remove the old crank sensor there is a collar and seal on it that will probably stay in the hole. Make sure you get this out otherwise the new sensor will not seal and will leak oil. My cars running has been totally transformed

 

I might take a look at the crank sensor next then, thanks

Edited February 11, 2016 by jamin

[AngusL 10]

As far as I am aware there is one crank sensor it's located as you look at the car from the front of the car just below the front engine mount on the right hand side of the lower engine block near the gearbox. It has a thick wire attached to it that clips apart. Really easy to change once you lift the front of the car up. Google its image. There is a wealth of info in here on it and the symptoms experienced when it goes.... And believe me hard starting especially when hot is one of the giveaways. You get no spark to the plugs and no fuel when cranking when this gives up but it becomes erratic as it fails.

 

There is also a camshaft sensor which is elsewhere and I have had no problem with that so not replaced it.

 

Interestingly I read that as this fails you loose 20 bop as the car uses the camshaft sensor as a fallback fail-safe mode. So when fixed power is restored and reliability takes a leap forward in terms of starting consistently. It worked for me for some months now.

[jamin 0]

As far as I am aware there is one crank sensor it's located as you look at the car from the front of the car just below the front engine mount on the right hand side of the lower engine block near the gearbox. It has a thick wire attached to it that clips apart. Really easy to change once you lift the front of the car up. Google its image. There is a wealth of info in here on it and the symptoms experienced when it goes.... And believe me hard starting especially when hot is one of the giveaways. You get no spark to the plugs and no fuel when cranking when this gives up but it becomes erratic as it fails.

 

There is also a camshaft sensor which is elsewhere and I have had no problem with that so not replaced it.

 

Interestingly I read that as this fails you loose 20 bop as the car uses the camshaft sensor as a fallback fail-safe mode. So when fixed power is restored and reliability takes a leap forward in terms of starting consistently. It worked for me for some months now.

 

Thanks for this info - I just found some more details on here also. Maybe I'll pull it out and cross check the part no. to make sure I have the right one!

[AngusL 10]

Guys given the symptoms long cranking before starting and intermittent cutting out. I've been there and seen this and it was driving me crazy as I couldn't figure it out but stuck with the research in here. Don't do anything else start with the crank sensor first. It's an easy to change part... And the issue is common to all modernish cars.

Like I said I changed mine in Nov 2015 and I have never suffered a bad start or a cut out and I'm doing some serious mileage in my car. There is no maybe about this it was the fix I needed. Hope it gives you guys the same grin I got once it's fixed and my power and reliability came back..

[fla 9]

Anyone had any experience of Lemark crank sensors? Are they oem quality? Only around £30 which seems very cheap but worth a punt.

[robrado974 1]

No experience with that part Fla, I got mine from TPS.

[fla 9]

Changed the crank sensor with a vw one i bought about 5 years ago. Seemed to improve but then went back to the long cranking again. Haven't got round to changing tbe blue temp sensor as access is poor because of the aircon pipes.

[Mawrick 0]

Have a look in my older thread here:

 

http://the-corrado.net/showthread.php?82988-VR6-hot-start-problem-seem-to-have-been-resolved-just-thought-I-d-post-experience/page3

 

it's years since I had major hot start problem, and knock on wood - after this cheap fix was installed I'v had no hot start problems........(I linked to the last page in the thread for more info read the whole thread...:) )

[fla 9]

Which way around does the valve go? I assume that it points towards the fuel rail? I've replaced the crank sensor and blue temp sensor but am still getting the long cranking when warm. Thanks

[fla 9]

Maybe my engine needed to adapt, but there is now so far no issue with the hot start, thankfully. The blue temp sensor was the culprit. Just i case the issue arises again i will put the check valve in place If that then doesn't work, i'll be stumped!

[robrado974 1]

Glad you got it sorted Hasan .

[fla 9]

Well it took a few seconds to crank today after a good run down the M4. So the sensor wasn't the culprit. I'll fit the check valve and see what happens from there...

[fla 9]

Fitted the check valve as per Mawricks suggestion. Just need to re route the hose as it turns a little too tightly by the pump

[Jim Bowen 1]

I can't remember if i solved this problem or not, think the engine self destructed before i fixed it. Maybe my valve is just old, am sure it had one when i redid the pipes etc

[fla 9]

Well this didn't solve my problem so it looks like an immobiliser issue with the obd2 although im using an emulator as a defeat.

[jamin 0]

Seems that my issue was that the non-return valve was all gunked up. The pressure in the line was dropping as soon as the ignition was switched off.

 

My car is now MOT'd and taxed for the first time in 4 years!

[georgaco 10]

Hi Guys,

I have just seen this and i have not seen any mention of the crank sensor. My car was getting harder and harder to start and was a bit inconsistent and odd infrequent cutting out at tickover. I'v had a split air inlet hose and seen the surging revs that that caused...Cleaned the ISV and MAF.. I did some reading in here and concluded that a dodgy crank sensor was a prime candidate. I bought a FIM brand fron ECP 79.99 fitted in minutes once the car was jacked up and the car has never missed a beat since... hot cold it starts first time every time. Hence I have not been on here for a while. I have had this issue since I bough the car a year ago but since I fixed this in Nov 2015 its been a fantastic runner. Note when you remove the old crank sensor there is a collar and seal on it that will probably stay in the hole. Make sure you get this out otherwise the new sensor will not seal and will leak oil. My cars running has been totally transformed

 

Have same problem with my vr6 / takes time to fireup when warm (the warmer the longer it takes). Guess will go for the crank sensor and see if it works for me. Do i need to go for oem? Any other proposals where to get it from (europe) and which brand if not oem. Not handy myself therefore wont be replacing it myself...!

[georgaco 10]

Have same problem with my vr6 / takes time to fireup when warm (the warmer the longer it takes). Guess will go for the crank sensor and see if it works for me. Do i need to go for oem? Any other proposals where to get it from (europe) and which brand if not oem. Not handy myself therefore wont be replacing it myself...!

[georgaco 10]

Guys, any feedback for the above post ref to the crank sensor? / thks

[robrado974 1]

If your not doing it yourself anyway, best to get someone to test the one you have .I doubt if a dodgy crank sensor will be the blame for poor warm starting . They are not cheap for what they are so you don't want to lay money out if your not 100 percent sure it's the culprit.

[g0ldf1ng3r 15]

IIRC the gf's old storm used to play up with starting when warm & i believe one of the things she had changed to fix it was the crank sensor

 

i cant recall what else was tried though sorry

[Dox 23]

Coolant temp sensor would be where I'd start, you can view its operation with VCDS.

 

Resistance increases with temperature so any sensor will have a harder time doing its job when hot.

 

Coils in general often give trouble when hot.

 

Checking for spark and fuel being injected when a non start occurs will help pinpoint what the issue is

[seanl82 23]

I still have this issue. It's not bad, so 2 or 3 cranks when cold, probably 7 or 8 when warm, although it's fine for maybe 15 minutes after switching off, then there is about a 30 minute window where other happens. I've replaced the crank and temp sensor, had injectors ultrasonically cleaned, and the only other suggestions have been fpr and fitting a non return valve on the return line at the pump end. Thoughts are that fuel pressure could be down at that point.

[Jim Bowen 1]

I was looking at parts diagrams and there seems to be a few valves within the fuel system and methods of testing them, like on the neck of fuel tank and the carbon cannister.