MISFIRE AND MANAGEMENT LIGHT ON BI-FUEL Mk6

[madmart132]

Hi the lambda is a lot more liable to be faulty than the cat start with that first , re the lpg is it a factory system or after market system there are big differences

[Calbo101]

The saga continues. Just in case you get in tge same situation. I got a lambda sensor for £46 at euro car parts and a new cat/exhaust for £160 at cats2u and the usual service stuff.
The mechanic discovered the exhaust had been welded together by Ford and had to cut the cat section off. The new one wouldn't go on as it was larger in one piece and after 2 hrs of us both trying he dismantled a few pipes to get it in but in doing managed to break the power steering pipe! Ford quoted £200 for a new one but the bloke knows a firm that can repair it so thats going there in the morning while he does he service. Good grief!! Beginning to wonder if it is worth all the grief!

[Calbo101]

What spark plugs does everyone use. There is so much conflicting info. Halfordsctried to sell me glow plugs ffs.
Update. Engine running. Had new lamda, CAT, a coil and HT lead that probably werent required. Took it for a short run and the cat was glowing red. It deffo struggles with power too. I even took offbthe middle exhaust to make dure it was getting enough air. I have noticed the new plugs that were put in are not the recommended ones (they are ngk pfr6B 3500 platinum. Foes anyonevthinkbthat vould be the issue? Any other suggedtions are appreciated.thanks

[metalworker0]

What spark plugs does everyone use. There is so much conflicting info. Halfordsctried to sell me glow plugs ffs.
Update. Engine running. Had new lamda, CAT, a coil and HT lead that probably werent required. Took it for a short run and the cat was glowing red. It deffo struggles with power too. I even took offbthe middle exhaust to make dure it was getting enough air. I have noticed the new plugs that were put in are not the recommended ones (they are ngk pfr6B 3500 platinum. Foes anyonevthinkbthat vould be the issue? Any other suggedtions are appreciated.thanks

if the new cat was glowing red ...you are going to need a new one again soon ..don't drive in this condition ..its glowing red because of unburnt fuel burning in it ..

costs nothing ..take petrol injectors out , switch ignition on ..observe if any are leaking

ps have you measure the voltages yet ..engine running / engine stopped

the plugs should help with lpg if they are the right grade , if your old ones are marked "6" ( the heat range) then you have nothing to fear

does it run the same on lpg as it does petrol

also ..you never said if the conversion to lpg is standard or aftermarket ..as someone pointed out above

[Calbo101]

Thanks. It is Ford factory fitted LPG
The old CAT was totaly broken up inside.
I have the mechanic coming back later to do a diagnostic. I dont know why he didnt do it before. Measure voltage on what? Sorry Im not very good with motors. I'm just going to pass any info to the bloke. I did another short run last night and pretty certain it is running on 3 and on both lpg and petrol assuming the gas was kicking in. If it was an injector wouldnt it run ok on gas?

[metalworker0]

i was saying in an earlier post ..
noting that you had instruments that stopped working at one stage

This is a classic symptom of :
low voltage in the system

caused by
Duff battery or alternator not charging or possibly loose or defective wiring

The knock on effect of having low voltage is ignition problems, that would be problems getting a good spark to ignite the fuel.

Which would lead to unburnt fuel in the catalyst

The battery should read over 12.25 volts with engine stopped
something like 12.75 volts or over with engine running

if you measure the battery voltage ( after you've had a couple of starts of the engine) as a newly charged duff battery can make 12,.25 volts but only for a short while .

LPG needs even better ignition conditions than petrol ..as its an insulator and there is more resistance for the spark to jump the gap at the plug - generally LPG would show a problem with the ignition system a long time before it manifests itself on petrol.

all the best..mark

[metalworker0]

i was saying in an earlier post ..
noting that you had instruments that stopped working at one stage

This is a classic symptom of :
low voltage in the system

caused by
Duff battery or alternator not charging or possibly loose or defective wiring

The knock on effect of having low voltage is ignition problems, that would be problems getting a good spark to ignite the fuel.

Which would lead to unburnt fuel in the catalyst

The battery should read over 12.25 volts with engine stopped
something like 12.75 volts or over with engine running

if you measure the battery voltage ( after you've had a couple of starts of the engine) as a newly charged duff battery can make 12,.25 volts but only for a short while .

LPG needs even better ignition conditions than petrol ..as its an insulator and there is more resistance for the spark to jump the gap at the plug - generally LPG would show a problem with the ignition system a long time before it manifests itself on petrol.

all the best..mark

[Calbo101]

Thanks Mark. The battery is reading ok.I'll have a contact cleaner frenzy just to see if that helps.

[Calbo101]

Update. Had new CAT, lambda sensor, plugs.
Took it a mile and the CAT turned bright red. I took off the middle boxes to make sure they werent the problem.it doesnt misfire when stationary but once moving it lacks power and think it is misfiring again. The management light comes on occasionaly and the temp and speedo guage dies but comes back on again. Any thoughts?

[metalworker0]

all i know ..happened twice to me in the past

again battery or alternator need checking out

You are only aware when the instruments stop working..you will not don't get a red light to say not charging .when this occurs .

and if it is any of what i mentioned..that will cause all the other faults you've experienced .

[metalworker0]

another possible cause

i don't know how a ford lpg system works

but most piggy back off the petrol injectors...the lpg connector is put between the petrol injector and the petrol connector.

all electrical power pulses for the petrol system are intercepted when on lpg ..and modified by the lpg ecu and sent to the lpg injectors.

any fault in the wiring, connectors or in the lpg ecu will mess things up.

[metalworker0]

if so you are then looking for a bloke called "woody" in an LPG forum on the net , i believe ( if i can remember , i may be wrong)he was tasked with the conversion of 100's ford vans for ford back in the years 2000 - 2010

just google
LPG FORUM woody - you will find him . Kieth woods

all the best.mark

corrected in edit to right person

[Calbo101]

Thanks. It is missing a bit while driving and the CAT is getting red still. It ticks over ok. If I switch over to gas at over 30 is clicks over but still runs rough but if I switch to gas while ifling or at low speed the engine dies as it switched over. My head hurts now

[madmart132]

Hi again you obviously got a few different problems
re the plugs I use bosch plugs the ngk ones are to wide a gap for lpg but motorcraft are good as well
forget about the lpg for the time being it will just complicate things for you
re the misfire , i had something similar last year after I had to change an engine on one of my vans , there is a small 1mil cable that bolts on to the back of the alternator it wasnt 100% tight and I had a lot of problems with it until I traced the problem ( it blew the centre box apart with one misfire ) look for that as its easily broken also the engine earth
Also the wires to the coils are thin and brittle look at them as possible breaking points in the ignition system

[Calbo101]

Hi again you obviously got a few different problems
re the plugs I use bosch plugs the ngk ones are to wide a gap for lpg but motorcraft are good as well
forget about the lpg for the time being it will just complicate things for you
re the misfire , i had something similar last year after I had to change an engine on one of my vans , there is a small 1mil cable that bolts on to the back of the alternator it wasnt 100% tight and I had a lot of problems with it until I traced the problem ( it blew the centre box apart with one misfire ) look for that as its easily broken also the engine earth
Also the wires to the coils are thin and brittle look at them as possible breaking points in the ignition system

Thanks mate. I'll have a look at that.At the moment i'm just going to replace the fuel filter just in case. Not sure how to but mr youtube may help