stranded at a mates 180 miles from home. HELP

[singerking]

 have a v8 lpg converted classic k plate. which is now driving hubby, my mate and me nuts. we are stuck as to where to go next and need some advice.

firstly we drove from somerset and after about an hour we ended up getting a warning light on the dash ( ! ) and the car wouldnt run on petrol but would on gas the light would then disappear then we could get it to run on pertol again. this continued to the point that we loast all power and had to pull over. after 30 mins we managed to get it started again on petrol and get further 30mins down the road. and lost all power on both gas and petrol. then our battery died called out the RAC who eventually turned up. while we were waiting we noticed that the condenser fans were going constantly.

well to cut it short we got towed to our mates house arriving at 0530 only 5 hours late. but safe. After crashing for an hour we set about the motor again.
we tried to turn her over and she was trying to fire but wouldnt light. when she did eventually fired she died the minute you applied power.

today so far we have done the following:

1. changed the ht leads.
2. checked the distributor and spark. all is good there.
3. looked at the mass air flow sensor, all good there.
4. put a brand new battery on her.
5. looked at the ignition coil and it get hot but runs the gas system ok.
6. put god know how much carb cleaner through her. got a massive pop when running on gas from the plehnum chamber. which improved the running system.
7. check the ignition switch and wiring and that looks good.
8. we have looked at the realy and it seams to be working as does the fuel pump

so fellas we are now banging our heads wondering where to look next and what it could be.

your help i greatly apperciated.

[bogie]

At the sound of how it all happened i would say there is a problem with the electrics on the gas set up,relay or something which is cutting your gas and petrol off???????????

[Range Rover Blues]

I need to know if the lpg system is a single point or multi point because if it's independant of the petrol system then your sympotoms are very different to if it's a multi point system.

The warning light is a fault on the EFi system and it would have to be serious for it to show up, like a lambda sensor etc.  mine doesn't even light if I unplug the MAF (should check that....) but the system will run on EITHER lambdas or MAF, so you probably have one sensor that's been down a while, or your ECU is going which is terminal.

Usually I'd advise getting the petrol side to work before tinkering with the gas, but let me ask how you have checked that the spark ignition is all ok, if the coil is running hot for example?

How did you check the MAF?  if you have access to a Haynes manual it tells you how to check all the sensors with a multi-meter, might help.

[singerking]

thank you for your reply.

well its a single point gas system. which is working sweet from what the boys tell me.
our motor doesnt have a lambada sensor(s). its an early model. k plate 1992.
i have been through the history of the car and it looks like it had this problem back in 2007 which they changed the fuel pump, ecu, ht leads, distributor, spark plugs, fuel filter etc and got it to work again. my concern is What is cousing it the fuel side to fail like this again.

i did check the spark ignition this was checked serveral times but removing serveral leads in turn and checking the spark from the lead against the engine block. we have replaced the ht leads now for a better set.  the coil from what i was told buy its old owner was changed just recently but as to why its running hot i dont know? and the condenser fans on the front keep running which to me indicates that the car thinks it excessivly hot even though its not.

i have ordered the boys to buy a multi meter today as mine is in my tool kit at home which is no good to me. and i personally think we need to start looking at what voltages are going where and see what we get. as you say check all the sensors.


I dont intend on going home until we have figured out why the car wont run on petrol as knowing my luck we will be an hour into my journy and she will dye again. and the rac have already said that they wont  recover us home as they recovered us to here.  arrrrh
thankyou again i will let you know how we get on  :)

[J.D.]

I am not up to speed on V8s but.....a friend had a problem where the choke jammed open on his carbs, meaning it wouldn't fire up when hot. Might be worth checking.

[DoubleTop]

try unplugging the thermostat, my v8 was extrememely picky on getting the right amount of air intake and that was massively affected by a stuck thermostat.  What was the temperature (ambient) when problems started?

DT.

[mark-d]

i would look at the coolant temp sensor

[Range Rover Blues]

The engine ECU can also turn the air conn fans on, when it sees fuel temp get excessive for example (even with the engine off, if fuel temp exceeds 60 degrees) plus there is a thormo switch on the thermostat elbow that turns the fans on if the engine gets too hot (there are 2 switches in fact).  Then the ECU has a differnet sensor to the temp guage, though they both sit just inboard of the thermostat on the front of the plenum.

Check the coil, it shouldn't be running hot.  I swapped mine 2 or 3 years ago, guess what? it's gone again.  It would start, idle etc but wouldn't run on LPG as the tank got less than half full and would start to missfire if I had been in traffic, very odd but it's fine now.

If it's a single point without lambdas is it a draw through (fully mechanical) or does it have an electronic control?  I'd guess at the former because most single point ECUs connect to he throttle posistion sensor and one lambda, often this has to be added so check to see.  If it's a non-genuine lambda it might be a cheap one, however this wouldn't then effect the EFi.

If you don't have lambdas then your engine shouldn't run without an AFM, mine doesn't.

It could be any of the sensors or the ECU itself, whay surprises me is that the car had all those bits swapped once already, so what's happened :-k

[Range Rover Blues]

Here's a tbought, can you start up on LPG and if so what happens? have you tried it on LPG with the petrol pump disconnected to check you don't have an injector stuck open for example.

one advantage of older single point systems is that they are independant of the factory ECU.

As for the breakdown, join the caravan club and take out their mayday breakdown.  Not just because it's far cheaper for the same cover, nor because the cover extends to breakdowns on your trailer, or even the fact that they will cover you for a trailer up to 23 feet (as opposed to the 14 feet covered by the RAC) but mostly because they cover you for a return trip if you can't get fixed.

The last time we called them out, they turned up first time with the right recovery truck, took us home then offered to come back in the morning and take it to a garage ;)

[gnasha]

have you cheaked the air flow pipe our old one did same ended up being a hole in pipe wrapped it up with gaffer tape lasted months till we got a new pipe

[singerking]

Sorry for the delay in getting back to you.
well to cut it short fellas, we got it running OK after checking and changing bits light went out it was great the next day put went to turn her over and the light was on again

well we have wired a switch in to get her to start on LPG straight away she runs OK on LPG just dont wanna run on petrol at all. managed to get her to my mates local landy specialist. and he had a look at her and confirmed what i thought it might be and that the ecu isn't talking to anything. he couldn't get his computer to connect to it. well according to the paper work the car had a new EC in 2007. we are now looking for a wiring snag. the bloke seams to think its ether the LPG wiring or there is a broken wire/ bad earth from the ecu into the engine.
this would agree with our diagnosis which when my hubby leaned across the bonnet to look at the pipes at the back of the engine block the light went out. only snag is hes not a small bloke lol

well tomorrow i am now going to have to look at the ecu wiring loom and see if i can find the break. i am hoping that once i have found the break the fault is fixed and i dont need a new ecu.


oh forgot to mention that she did get us home today running on LPG and it was a smooth journey. :)

[Bowie]

If you need an ECU I have two sat on the shelf here doing nothing..... and not a million miles away?