Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: krivoyrog25 on 07 July 2010, 16:58:58

Title: hot start valve? Heisstartventil 2.5TD
Post by: krivoyrog25 on 07 July 2010, 16:58:58: Hi All,

I have stumbled across this little part on Ebay.de in my quest to find out why my TD has such a difficult start when hot. Not in all forums I have visited have I found any reference to this part, yet it seems to be an original part. It is made by Pierburg who also makes parts for BMW.

I apologise for being stubborn on this subject, but when I read forum members replacing the almighty injectionpump at great cost and still having the hotstart problem, then in my view it is not the pump at fault.

I also doubt the 'hotstart' fix as offered on ebay, I can simply not believe that the Germans cannot come up with an idea like that themselves, and sell this M51 engine for so many years with this problem.

Anyone perhaps know where to find this part under the bonnet, haven't been able to locate it yet.

http://cgi.ebay.de/Omega-B-2-5-TD-VENTIL-PIERBURG-HEISSTARTVENTIL-/360274725336?cmd=ViewItem&pt=Autoteile_Zubeh%C3%B6r&hash=item53e20c09d8
Title: Re: hot start valve? Heisstartventil 2.5TD
Post by: Omegatoy on 07 July 2010, 17:37:04: weel i dont recognise it? have you tried having a bottle of cold water with you, then when you want to start with the engine hot, pour the water over the injection pump then try starting it, if it starts better then its the fuel temperature sender is at fault, this is easy to replace and usually cures the fault :y
Title: Re: hot start valve? Heisstartventil 2.5TD
Post by: tidla on 07 July 2010, 18:45:56: i thought it was an electrical device/relay which fixed the propblem??

mod was fitted to the beemers and range rovers.
Title: Re: hot start valve? Heisstartventil 2.5TD
Post by: Marks DTM Calib on 07 July 2010, 20:09:43: Looks a bit like the EGR vac actuator valve...
Title: Re: hot start valve? Heisstartventil 2.5TD
Post by: Omegatoy on 07 July 2010, 20:45:49: Quote
Looks a bit like the EGR vac actuator valve...

good call it could well be!!!!
Title: Re: hot start valve? Heisstartventil 2.5TD
Post by: MickAP on 08 July 2010, 10:45:05: Quote
Quote
Looks a bit like the EGR vac actuator valve...

good call it could well be!!!!

So could fitting that part cure hot start probs?

Mick ;)
Title: Re: hot start valve? Heisstartventil 2.5TD
Post by: krivoyrog25 on 09 July 2010, 17:52:02: Hi All,

Today I had bit of time to have a good look under the bonnet. It appears as suggested by one of you that the hto start valve is indeed an (vacuum) actuator for the EGR valve. There are 3 rubber lines and an electrical connection on this valve.
Looking at the engine and the position of the EGR valve itself, I believe (specially because mine is covered in black oily gunk) thta if the EGR dpoesn't operate freely, as in can be moved by vacuum, you will have a hotstart problem.
because of the M51 design, glowing is not really required when the engine is hot, however, a richer mixture will aid the starting of the engine. As in the original design, the liftpump will not run outside the glowmode, thus preventing the mixture to be enriched by increased fuelflow.
So, another way must be found, I believe the engineers have found this by means of the EGR valve, if you restrict the airflow in a situation where the fuelflow remains the same, you end up with a mixture which is richer and the engine starts smoothly even when warm.

This actually makes sense to me, as my engine certainly sounds like one that's not getting enough fuel when cranking it over. It's fairly similar to first cranking after fuelfilter change.

I will now change out the hot start valve, and clean the EGR and manifold assy.