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CNGBiFuel Apr 13th, 2018 02:18

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Necam Stepper Motor Type A
Two views of the far cheaper Necam Stepper Type A fitted to S60 & S40 and pre 1998 P80 cars. Subarus, Vauxhalls, Ford Transits etc have these too.
If you have a V70 or a S80, you are unlikely have this type.

CNGBiFuel Apr 13th, 2018 02:23

2 Attachment(s)
Necam Stepper Motor Type B
Two views of the Necam Stepper Type B unique to Volvo. Identified by its flat top. You can usually expect to find your V70 or S80 with this type.

CNGBiFuel Apr 13th, 2018 10:42

Professionals in the UK
To add to the list of pros I know to have extensive Necam experience:
Flintshire Autogas Chester

CNGBiFuel Apr 19th, 2018 23:44

1 Attachment(s)
The distributor is mounted on M6 rubber mount bolts. These perish and you'll often tear the rubber getting the mount off.

Whilst I advise you to move the distributor anyway, you'll still need these.
Look for Landrover/MG V8 fuel-pump mounts or Facet fuel pump mounts. eBay is your friend here

CNGBiFuel Apr 20th, 2018 07:37

1 Attachment(s)
Else, search for Anti Vibration Rubber Bobbin Damper Mounts.
I'll cover electrics, the main relays that fire the system, setting up the regulator / vapouriser and the two versions of the ECU. Unfortunately most of the offiial Volvo stuff I have on these systems is in German. The English versions may exist, but numerous attempts to get it via Volvo have failed. Quoting Volvo's own part numbers for the German manuals I do own has Volvo parts counters saying the items do not exist. Volvo's own support to dealers was always poor - they don't know much.

CNGBiFuel Apr 27th, 2018 04:03

1 Attachment(s)
And in no particular order, as these occur to me:

Parts in the Necam EGI distributor.

These parts are found inside the dizzy. Leaving out the spring-washer (c) will prove a very expensive mistake, the stepper bottoms-out and then fries. You have been warned. The piston goes on with the thinner walled end away from the motor body. ie the thin walls go into the distributor cylinder. Unsure what I mean by this? inspect post No.10 in this thread.

CNGBiFuel Apr 27th, 2018 16:01

1 Attachment(s)
Lubrication of the piston in the distributor.
Not sure I made this point very clear before, but don't lubricate with WD40 or similar. WD40 contains silcon, and as it works its way to your Lambda (O2) Sensor you'll be springing for another.

Use the same stuff as those in Lycra cycling shorts. The 'I was never confused' crowd use GT85 on cycle-chains. Use this on your dizzy piston, and spray some every time you clean your dizzy.

If you've been paying attention, you've moved the whole shebang out of the heat by now anyway, so it's a 1 minute job to remove you stepper and fire a shot of Wynnes or Comma injector cleaner in there anyway. Finish off with a squirt of GT85. Careful many PTFE sprays have silicon.

Be very wary of your first can of GT85. It's a thin line. I seem to manage to resist the homoerotic temptations of GT85, Lycra shorts, wrap-around shades and an XC90.

For some it's too late:regular_smile:

CNGBiFuel Apr 29th, 2018 10:24

To recap:

Move your stepper out of the heat. Every 4-5000 miles Whip it out (ooh er missus...) - fire some injection cleaner into the port. Let it soak overnight with a 2p coin as a cap to stop evaporation, then give it a squirt of GT85 (silicon free) PTFE/Teflon on the piston (aka plunger).

When you install the motor it will be lumpy or stall for the first 3-4 starts until it zero's to the ECU. Normal. Rinse and repeat.

Fail to do this and next time you want to replace the stepper I suspect you won't get one at any cost. These units suffer from a Triac issue, and not all can be repaired, and Necam don't seem to be making them anymore. My own supply is limited. If there was one Achilles Heal to the Necam system, it is that parts are getting scarce.


CNGBiFuel Apr 29th, 2018 10:42

4 Attachment(s)
ECU Modules etc
I'm dreading this bit, largely because everything I have is in German, and is a mismash of models and crossovers, and badly translated German! It seems Volvo did not keep good records with respect to Tech-Support to their dealers for Necam cars, hence it'll not be long before you can claim to know more than dealers ever did. And the manuals are not brillaint, the 1999 cars are pretty much the same as he P2 Necam cars

P80 models up to 1998 have two modules. It gets more confusing with later cars, I'll cover those in a mo'

P80 Boot ECUTank Module:
On my P80 it's located under my tank. I am not sure where it lives on LPG P80s.
The one in the boot looks like this:


CNGBiFuel Apr 29th, 2018 11:11

2 Attachment(s)

P80 Boot ECU Main Module:

Found in one of two positions on the pre Denso (1999-2000) P80 cars, it's located either under the bonnet, in with the main Engine and transmission ECUs (in the black box ) on the opposite side to the battery or by your steering column.

I do have one manual for the early cars.

Later Denso P80 cars (circa 1998-1998 seems to be the swap date) still have the tank ECU, but do not have this ECU. Front ECU gets incorporated in with the main Denso ECU. If your car is Denso, with a Denso MAF, and Magneto Marelli ETM this applies to you.

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