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capt jack · Nov 15th, 2012, 11:34

Hi there

I have exactly the same problem with my 1997 V70 LPG conversion - oscillating idle when cold. On petrol it is running absolutely perfectly.

The LPG system is a Tartarini system, and has been on the car for 8 years and covered over 220,000 miles. In total the car has done almost 280,000 miles.

I've fitted new LPG injector solenoids, a new LPG filter, and have replaced the thermostat and the coolant temperature sensor. I also thoroughly cleaned the throttle body and fitted new spark plugs, and had the fuel trims re-mapped. All these things helped a bit, but none of them completely cured the problem.

Having spoken with the fitting company, they say that the most likely cause is that the gas regulator is simply worn out, and that it needs to be replaced. The rationale being that the system cannot maintain gas pressure when cold. Tartarini do offer a service kit for the regulator, but I reckon that as the regulator has done such a large mileage, it would be more sense to replace it.

I am going to replace the regulator and the gas temperature sensor next week, so I will post the outcome on here.

The main worry is that although the car drives well on petrol, and reasonably OK on LPG when hot if I run it on LPG for any length of time the LPG ECU upsets the petrol ECU, then I need to re-set the petrol ECU by disconnecting battery, or the car won't start on petrol! I also get random fault codes, all related to fuel trim. If I don't use LPG at all then car runs very well indeed, with no oscillating idle, no difficult starting and no fault codes.

I am hoping that a new regulator and a fresh re-map does cure the problem because petrol is getting expensive!

Cheers

Jack

Nov 15th, 2012, 11:34	#10
capt jack VOC Member Last Online: Yesterday 19:23 Join Date: Jun 2006 Location: Selby, North Yorkshire	Hi there I have exactly the same problem with my 1997 V70 LPG conversion - oscillating idle when cold. On petrol it is running absolutely perfectly. The LPG system is a Tartarini system, and has been on the car for 8 years and covered over 220,000 miles. In total the car has done almost 280,000 miles. I've fitted new LPG injector solenoids, a new LPG filter, and have replaced the thermostat and the coolant temperature sensor. I also thoroughly cleaned the throttle body and fitted new spark plugs, and had the fuel trims re-mapped. All these things helped a bit, but none of them completely cured the problem. Having spoken with the fitting company, they say that the most likely cause is that the gas regulator is simply worn out, and that it needs to be replaced. The rationale being that the system cannot maintain gas pressure when cold. Tartarini do offer a service kit for the regulator, but I reckon that as the regulator has done such a large mileage, it would be more sense to replace it. I am going to replace the regulator and the gas temperature sensor next week, so I will post the outcome on here. The main worry is that although the car drives well on petrol, and reasonably OK on LPG when hot if I run it on LPG for any length of time the LPG ECU upsets the petrol ECU, then I need to re-set the petrol ECU by disconnecting battery, or the car won't start on petrol! I also get random fault codes, all related to fuel trim. If I don't use LPG at all then car runs very well indeed, with no oscillating idle, no difficult starting and no fault codes. I am hoping that a new regulator and a fresh re-map does cure the problem because petrol is getting expensive! Cheers Jack Last edited by capt jack; Nov 15th, 2012 at 11:38.