280 / 06 / LPG/ Problem.

[simwasere]

I think in the main ford system is the necam EGI but there is two main systems that are factory fitted to many car manufacturers e.g vauxhall, saab, subaru,
The GSI system is the main one for vauxhall,in the gsi the gas is metered with electronic injectors,
The EGI system is the main one for fords in the egi system the gas is metered by the distributor via a stepper motor which moves a piston in the body
that has little tiny v shaped slits in side 6 in all (2 blanked off) the slits are paper thin the smallest feeler gauge just gets to the bottom of the slits,
Thats why it can have a big effect on the mixture and the running of the engine,ie weak mixture,
But they're easy to take off and clean.
The vaporiser also plays its part by warming the liquid gas (lpg) and turning it in to yes gas (vaporised) and keeping that at a constant pressure.
because of tank pressure and ambiant air pressure are always changing.
the vaporiser has a vacuum pipe attached to it for the increase and decrease in engine load,
so it can produce more gas pressure when needed.

[M4tty]

Thanks for the reply mate your teaching me loads and it's really appreciated.

I think maybe the stepper motor may Be the problem possibly. Do you think the stepper motor would cause the engine to shake when accelerating. It idles ok but as soon as I accelerate out of gear it revs up but there's a flat spot but if it's in gear the engine shakes vibrates and doesn't stop vibrating till I hit 3500 rpm then it seems ok but in fifth gear that's 75mph so I need to get this LPG fixed.

Where would you start?

Any info would help and thanks for helping us out here.

[simwasere]

I would defirnitly start by removing the gas distributor and open it up and give it a good clean my van did the same as your's!!!now drives as good on gas as petrol
If it's missing abit on one of the cylinders you can pinch one of the four pipes that come out the top of gas distributor and listen for a different
engine tone to determine fuel line which is blocking up.(so one of the slits in the distributor is deffo blocked)
Is your necam system EGI or GSI,
And yes the stepper motor will give you the problems you are having but you can't test it tho,
also the diapham under the three screws and plate at bottom of gas distributor,
if it has a split or torn it will need to be replace and stretch the spring abit that sits against the diapham,
http://www.askanowner.com/qa/view.asp?s=1&qid=275180

[CROSSFIREROB]

Well im sort off getting somewhere on mine , i did as you said SIMWASERE , when the green bottle light began to flash fast , i pulled over switched off the ignition and then started the van again, after that the van ran fine and the light never flashed at me again all the way home . So would you say mine is a heat scenser problem .

Matyty i would have killed my van by now , hang in there mate

[simwasere]

The gas ecu looks for a signal from the temp sensor so it knows the vaporiser is up to temp,(about 32 deg)thats why there is a delay before it swiches to gas.
from flashing gas bottle to solid green gas bottle,
its a two wire sensor on top of the vaporiser difficult to get at and test, i think it has 1.2 volts to it from ecu and works on a resistants
with perminant ground.
You will have to use ohms meter to test and check the ground, or you could just replace the sensor i think they're two different types.
you must get the right one.
Does it when running on gas run well or poor?
i say this because mine was running ok but on the weak side, but when going down long steep hills with foot off accelerator engine braking used to switch back
to petrol,cleaned the distributor and no trouble since!!hope this helps

[M4tty]

I hope you dont mind me posting on your thread crossfirerob but simwasere is helping out no end on this thread so ill post here for time being.

When the van is ticking over on petrol, there is a slight misfire (not under load) vacuum reading is good and steady at 21 inch/mercury? So I believe there is no vacuum leaks on intake manifold. Ive replaced the plugs for NGK Irodium, New coil packs, new ignition leads, new lambda oxygen sensor (pre-cat), cleaned MAF sensor. No fault codes being stored on petrol ECU.

When the engine is switched to gas there is a distinct misfire throughout the rev range which shakes the engine irratically which make it undrivable. The coolant system is full and the vapouriser is hot to touch. Also the van switches from petrol to gas no problems so the temp sensor on vapouriser must be reaching is 32 degree setting as the system switches over to gas no problems. Ive also kinked the gas feeds one at a time and each one makes the engine run erratically equally the same so i believe its not a problem with one particular injector. The problem must be across all injectors. Does this point to a blocked filter/distributor?

Ive checked the throttle position sensor for resistance readings and its 0.77 ohms between middle pin and outside pin at idle which rises to 3.71 Ohms at full throttle and is consistant all the way through.

If I need to take the distributor off to service/clean it. Can i just dosconnect the gas pipes from it or will the gas leak out everywhere?

I know some of my questions may be amaturish but ive never worked with LPG system before however I have rebuilt engines before so am reasonably competant to do this. Any advice appreciated and if anything ive said above is wrong please say so as im always willing to learn.

Thanks again

Matt

[M4tty]

Also im not sure which system i have on my van whether its GSI or EGI. If anyone can tell from my pictures it would be appreciated.

The link is http://s1201.photobucket.com/upload/albums/m4ttyd/

Thanks in advance. Pictures not great but best i could do

Thanks

[simwasere]

Yes you need to loosen off the four pipes on the distributor ease off the big pipe on the bottom of the distributor. This pipe has a gas filter which is between the vapourizer and the distributor and is easy to change..might hear and smell a little gas you can remove the fuses or keep gas system switched off, Remove the electrical connector on top that is attached to the stepper motor (four wires) and remove the connector to the dfco solenoid on the side of the distributor. This solenoid switches gas on and off for over run and deceleration. Its a fuel saving device and saves on emissions. As for your van you need to sort out the mis fire on petrol because rnisfiring on gas just amplifires the misfire problem.
http://www.askanowner.com/_upload/1_2/a ... ivider.pdf

[simwasere]

also can't see photos for some reason?

[CROSSFIREROB]

quote
"I hope you dont mind me posting on your thread crossfirerob"

AS IF MATE .

[M4tty]

I'll sort the photo link out on the computer in a bit. What do you recon would be causeing a misfire on petrol ? It's had new plugs, leads, coils and the misfire is not a heavy misfire it's very slight and can only be noticed when ticking over and there are small flat spots on acceleration at low revs. Any ideas please. I've tested the tps, it's had new oxygen sensor, no codes are being read from ecu. Cleaned the maf sensor. Any other sensors I can check?

Thanks in advance for any help here

[M4tty]

http://s1201.photobucket.com/albums/bb346/m4ttyd/

hope it works this time

[simwasere]

Looked at your pictures m4tty defo EGI system the first three pics are the gas dizzy bottom view,
hope this helps?

[simwasere]

Have you checked the map sensor and the vacuum pipes it sits on the drives side bulkhead.

[M4tty]

I haven't checked the map sensor simwasere. What's the best way of checking this? Thanks