MODMIN Make this a Sticky FACTORY BIFUEL CLEAN IT NOW!!!
 

Please Modmin make this a STICKY.

DO YOU HAVE A FACTORY BIFUEL?

DO THIS AND DO IT NOW.

At the route of almost all the queries on factory Bifuels in this section is the NECAM stepper motor.

I run a Volvo Bifuell, a factory fit Necam/Koltec distributor system. At the moment beuase the stepper motor in this system is a £320.00 Volvo only item and very, very fragile, I look after it by firing injector cleaner in my distributor every 2500-3000 miles and leaving it to soak. It stops it gumming up and overworking (and thus popping) the pricey stepper motor. They can go bang every 40-50,000 miles if you don't do this. The heavy ends in the gas gums up the distributor and thus this mashes the motor.

The motor moves a piston up & down and works very hard. Keep it clean, and make sure it doesn't work any harder than it has to fighting heavy-ends etc etc.

Very easy to do. Engine off, [don't smoke] get a 3mm Allen Key and remove teh 2 x 3mm Allen bolts holding it to the distributor. You should turn the gas off, I don't bother, you'll just get a hiss for 3-4 secs before it subsides. Work outside!

Lift the stepper motor out. Do it slowly and then pour a non-silicon based cleaner in there. I used Wynns Injector cleaner. STP is dear. Comma is good.

Not used it but I've since been recommneded by classicswede IC12 LPG Injector Cleaner 50ml

Leave it to soak for 3-4 hours at least. Overnight? Replace. Job done.

That stepper motor is almost identicla to the £40.00 Vauxhall Necam part but being Volvo they wnat a Volvo price. Look after it or cry.
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If you value your Lambda, leave anyhting silicon-based well alone, and Carb or Brake-cleaner will rot seals. Put some more Wynns in your petrol too. Stops the injecotr leaking and making you burn petrol when running gas.
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I will be very Draconian on this,

DO IT AND DO IT NOW.

I done this with mine, but I split the main hose feeding the distributor from the filter, fill the hose with cleaner, rebuild, warm the engine using petrol and switch to gas. Depending on your mood you can switch between petrol and gas holding a high rev until it runs on gas again, or let it die from a high rev and leave it overnight. This cleans the distributor and the injectors.

On a side note, I put injector cleaner though the petrol and the engine seems to run better when on gas.

Yes, injecto- cleaenr is your friend. Better running on gas would be becuase you likely had leaky petrol injectors messing up you metering. Did it a small amount of petrol on gas like mine did?

If one leaks you'll be getting neat petrol flooding one bore and the lambda weakening everything globally, so it'll run weak on the otehr boress. Higehr wear and lower performance and burning petrol too. More on thsi at:

http://www.volvoforums.org.uk/showthread.php?t=183595

I used a tiemr relay in the finish...

If yo have the P2 model it may be easier to put he clener in the hose, the distributro ia hardly easy to get to. But put it in via the motor if you can, via the hsoe is not so targetted. On a P1 like mine the distributor sits above the engine on the bulkhead so this an easy job.

Hi,
I have a 2002 v70 factory bifuel,do you mean soaking the stepper motor?

thanks
John

From memory as I've now sold my bi-fuel.....

Get a bottle of STP fuel injector cleaner, disconnect the pipe from the dryside gas filter to the distributer. Pour about half the bottle of cleaner into the pipe and refit the connector. Run the car until it switches to gas, the engine will stall. Leave the car overnight, if you need to use it switch it to petrol. Start the car after a few hours (I usually left mine overnight) and let it switch to gas - the car will cough and may stall but will soon settle to a nice idle after the excess cleaner is cleared. Bob's your uncle!