hi FM'ers,

my car runs duel fuel, the gas has been tuned. idle is fine rearly stalls now.

PROBLEM: while driving (hot/cold doesnt matter) the gas seems to freeze. as in more than 5mm throttle itll cut out (and if pushed to floor it will backfire after a few secs), give it 30secs>2mins on petrol and its fine again.

it usually only happens after 20mins+ light highway (90% of tme this happens cruising at 100+) rearly ever does it if its getting a booting.

under advice, once when it did this i pulled over and checked the converter and it wasnt frozen, was as hot as the motor still.

this has got me and a few mechanics stumped.

thanks, sorry for long post,
Rushed

well if the convertor not frozen then the gas is being converted from liquid to gas

u have another problem somewere could be a faulty relay or earth wire cuttign the gas supply to the convertor

blocked line or relays, or converter cant supply enough to run motor--damaged rubbers or internals

Backfiring with LPG is usualy caused by poor elelctrics. I would suggest changing your coil if it's an EL, as I had a similar problem and that is what the cause was.

ah this old nugget!

your water lines are incorrectly set up. its either got an air lock or the heater hoses are both flowing in the same direction. This cancels out the flow and the convertors freeze.

I typically suggest running the hose from the thermostat housing direct to the convertor then back out the convertor to join in with the heater tap. There shouls be a smaller bypass hose so that when the tap is closed the water is still flowing through the lines and consequently the convertor. I have seen these removed and it stagnates the water when the tap is shut.

Also i've seen people T-off the heater hoses and the water just follows its natural path and almost seems to ignore the convertor being there.

Check that the hoses are not pinched by being too long. They must have a nice flow path.

If you run it the way i mentioned it will always get the hottest water first.

Another less likely cause but one worthy of investigating is the lock off itself. Few people know it but there is a filter in the lock off to trap crap from your tank. Also the solenoid doesn't always travel the lock off to the fully open position. This can present as a blockage, reducing gas flow to the point where it will just idle but not drive.

I've had all these issues in the past. That last one had me stumped for ages.

HTH

also check thermostat as most EA etc onwards have 2 stage thermostats and you need to remove some of the bottom section (tinsnip half of the lower section) as you will get no water flow thru when the engine is cold, this is what could be happening when cruising highway speeds. eg thermastat closing shutting off or restricting water flow to LPG convertor.

some good ideas, will try them tomorrow. yay for day off.

i must ask "gas filter" where would it be? as the gas system is from 1995, tank and lines were redone 18 months ago when i got the car. but ive never heard of a gas filter. ill try to get a pic of the convertor if itll help

edit: my gas water hoses are 5 months old (were splitting due to touching extractors), i got longer ones so they dont go near the extractors, and are t'd in two places under the coil packs, same as i took them off, as i did one at a time.

hi all my ef is doing the same but not all the time it just decides to not run on gas when the weather is in the low (18 degrees) but when its up in the 30`s it runs perfest on gas.

ive only had the car about 3 months and the person that had it befor me took the stepper motor off the converter and put an older style gas flow valve in, just wondering iff that would have anything to do with it.

any help would be grately appreciated.

gas filters are under the solenoids in the bowls and collect scale and rubbish from the tank, and can block up. you have 2 of them- front at motor and by the tank------remember to turn the valve off and run motor till lines are empty. test for leaks with soapy water in a sprayer when finished------check line joints and fittings, good hunting

hey the convertor is hot and not frozen suggesting the hoses are allowing hot coolant flow

i do liek your 2nd theroy though

1. split pin holed or stretched diaphragm
2. wax build up

either way your convertor is the issue. ~$88 for a reco kit or sell it on eBay and replace with a new one.

my 2c

I'm with Aaron on this one, definately a convertor prob by the sounds of it.
Your filter is in the main lockoff close to the convertor, the one at the tank shouldn't have a filter.
If it's a Poliauto or Vialle convertor then i'd say that's your problem for sure!
If it's knackered then buy an OMVL R90E, they're an excellent convertor, they rarely give any dramas, unlike the Poli and Vialle.
If you want some guidance then drop in oneday on your way through, seeing as you pass right by me.

it is an omvl r90e

the same as the one in the pics at the top of this post.
http://fordmods.com/forums/viewtopic.php?t=41491

although where it has a "t" peice inbetween the convertor and the t/body i have an electronic shutoff valve, looking thing.

i dont have a balence line? could that do this?

i talked to a gas place and they said you CANNOT get a convertor on its own as "there all sold with the complete kits" he also laughed at me when i asked, that made me happy

any help would be great, on how to "rekit" it if thats what is needed.

update i found a pic of it. hope this helps.

Ah piss me off!!!!!
I just wrote a long reply and clicked submit, then it told me i was logged out, so i logged in and lost it lol.

Anyway, a balance line wont hurt it any, it's always worth throwing one on.
The thing you described sounds like the stepper motor, it is possible that that could be causing your problem, it gets it's signal from the O2 sensor, if the O2 is playing up it can tell it to lean and the piston will screw in.

As for not being able to buy a convertor on it's own, he's on f**k drugs, i could get one anytime you wanted it.
I put a kit through mine a few months back, don't know the cost as i bought a whole heap of stuff at the same time, i can find out though.