A Little Rough On Start Up

[mikej]

MK2 2.3 GHIA 2001 MANUAL ,

I seem to have developed a small problem as off late to go with all the other small problems these cars have lol . Any how my gal is lpg converted which means on startup it starts on petrol and carries out a few checks throughout the gas system together with waiting for the car to achieve 51 degrees before automatically switching to gas , the car runs as sweet as a nut on both gas and petrol and you cannot notice any difference at all between switching even manually however when starting first thing in the morning or even when the car has been left for a good few hours etc it runs rough untill warm or swiched to gas , the best way off describing this is for those of you who are old enough to remember manual chokes , it feels like driving a manual choke car on a cold morning with the choke in you really have to feather the throttle as not to bunny hop up the road to much or to little and its as rough as a bears behind untill its warm then its fine , it almost feels like its runnig with a misfire however all plugs and leads are good and its not exactly under load when just started ! and if i boot it it respnds without any issues ?

 

Anyone any ideas or suggestions pleas???????? :)

[sepulchrave]

Yes, your injectors are dirty or clogged due to lack of use and/or your petrol is stale (happens quicker in summer).

 

Whip off your injectors and get them ultrasonically cleaned, drain the stale petrol from the system, do a fuel filter change, and put nice fresh good quality petrol in.

[mikej]

I thought it may be something along these lines , petrol is fresh , refilled tank twice this week and car runs fine . Have just done 500 miles on petrol with no real difference although car was obviously warm by then , however i was thinking the lack of use may be the issue , i thought i may start with the fuel filter first though . Funny how its old when starting from cold and it only lasts a few minutes then its fine again !

[mikej]

Sorry to drag this up again but this has me stumped as it only occurs from a cold start and lasts no longer than a minute of driving after which the car drives A1 on petrol or gas recently drove a few hundred miles on petrol and car doesn't miss a beat , ticks over perfect , pulls well or as well as any normal 2.3 . If as already mentioned its blocked injectors , which it could well be as a result of lack of use would it only last a minute or so from a cold start ?

 

Does anyone know the price of replacement injectors for the mk2 2.3 16v or recommend any cleaning service provider and a rough cost for servicing them ?

Any help would be gratefully appreciated .....

mike. :angry2:

[sepulchrave]

I don't know where you're located mikej, but many places have an ASNU injector cleaning/testing machine (we do) and prices are usually quite reasonable for four standard injectors. Try your nearest Bosch approved service centre, if they don't have one they'll know where does.

[Steve P]

I suspect this will not be easy to fix!!

 

Our galaxy is LPG converted - but it was done many years ago and is a single point injection. This switches over at any temperature - even stone cold. It switches over after the engine revs have been above about 2500 rpm and then decelerate - for example when changing from first to second when driving off. This system switches over fine and runs OK on petrol before switching over.

 

My vectra has a factory fit LPG and this operates the same as yours, although the temperature required to allow LPG operation is much lower - probably about 10 degrees so in summer it's straight away after starting.

 

Anyway my vectra has almost the same problem - but lower temperatures make it worse. Today when it switched over to gas it stuttered quite badly - so much that the system decided to switch back to petrol. A minute or two later I forced it back onto gas and it ran fine. However i know that as the mornings get colder this problem will also occur whilst it is running on petrol before switching over - it did so last year but I never got round to fixing it!!

 

What is the relevance of all this to your problem? Well LPG exaserbates any problems with the engine - e.g ignition faults show up worse on LPG than petrol. So it could be that we have the same problem - and if your car switched over to LPG quicker it would be even worse. For info I have just had a fault code reader on mine and found nothing.

 

A cold engine needs everything to be more perfect than a warm one - which is why you need fuel enrichment (choke) on a cold engine.

 

I'd be tempted to get the fault codes read - to be sure that the temperature input to the ECU is sensible. If this is out the ECU may not be supplying enough "choke".

 

It could be the injectors - if they are blocked a bit again this might mean that they cannot supply the right fuel for the "choke" when cold. You might not be able to feel this at other times - at higher revs when you have been running on petrol. Personally I don't think it is the injectors but would not be prepared to bet on it!!

 

The other is plugs. Are the gaps correct. Have the plugs been changed? Have you got a HT lead breaking down (or a coil pack).

 

I've got investigate my Vectra - I'll let you know if I get to the bottom of it.

 

Cheers

Steve