92 RRC Cutting out

[DC_]

Hi Folks,

First post here, you's were recommended by another 4x4 forum as i have just bought a 92 RRC 3.9 vouhe EFI Auto.

It's been converted to LPG. There is a problem with the running of it really. Seems to run fine on petrol but when i swap it over to LPG after the engine has heated, it runs ok on it until i come to a halt. Then when i put the accelerator back down to go, it cuts out.

Today it cut out for the first time on petrol. Tomorrow i will renew the spark plugs and i have put shell V Petrol in along with redex to see if this will make a difference.

Can anyone suggest what may be the problem with the LPG?

I know where the 2 screws are to adjust the settings, but i dont wanna mess with it incase i make the problem worse.

DC

[Highway_Star]

Get it running reliably and well on petrol, then look at the LPG, the reason I say this is that LPG is a harder fuel to ignite than petrol.

There's all sorts of reasons for cutting out, but if it's ilding ok when you come to a halt, then falters and stalls when you ask for power I'd be looking at the ignition, plugs, leads, coil, cap and rotor (only ever use GENUINE LUCAS cap and rotor), the advance/retard mechs on the lucas dizzies are notorious trouble spots too, then look for air leaks, then things like TPS, (is it working, is it set correctly), O2 sensors, temp sensors. Some LPG systems sniff information from the vehicles own sensors, some employ their own sensors, some have no sensors at all.

The LPG system might be in need of servicing, cleaning the filters and emptying the heavy ends out of the vaporiser, often a new diaphragm is needed in the vaporiser, find a good LPG specialist locally, or gain the knowledge and DIY.

[geoffbeaumont]

Sounds exactly like my old rangie was before I ditched the standard ignition system. As Highway Star says there are a number of other things which could be causing it (and if your spark is weak then the LPG system will show up other problems as well, as it's already struggling to ignite), but if you look back through the old threads on here you'll see that the vast majority of V8 problems, especially when on LPG, are ignition related.

[DC_]

Sounds exactly like my old rangie was before I ditched the standard ignition system. As Highway Star says there are a number of other things which could be causing it (and if your spark is weak then the LPG system will show up other problems as well, as it's already struggling to ignite), but if you look back through the old threads on here you'll see that the vast majority of V8 problems, especially when on LPG, are ignition related.

Thanks Guys, i have put £30 of shell V power fuel in along with Redex system clean and already after only running it on that for a few miles it seems to be a little better.

I have the spark plugs (NGK) at the ready just need time to fit them.

I have patched a couple of blows on the exhaust and it's sounding better...... will fix it properly when i have cash for it.

Does any of you know a good landy guy in west of scotland that can tune the V8 up?

I think i'm also in need of a starter motor, the one at the mo is clicking from time to time then kicks in.

Will also change the leads and distibutor cap and rotor arm ASAP.

So......................only lucas parts?

DC

[geoffbeaumont]

So......................only lucas parts?

If you're planning on keeping the truck for a fair while, seriously consider fitting Ford EDIS ignition and some flavour of Megasquirt to control it (plenty of info if you search this forum - there's a good introduction by FridgeFreezer in the tech forum).

However, right now I'm guessing you're more interested in just getting the standard system running adequately to keep you mobile. To that end fit:

• new NGK plugs (you seem to already have this covered). Gap them a little less than standard if you're running LPG.
  
• Fit genuine distributor cap (only a few quid more and very much money well spent).
  
• Fit genuine leads (decent quality and reasonable money), or quality aftermarket - I had Mallory, which were good, but there are a lot of charlatans selling bling rubbish for silly money. I'd just go for a set of standard ones and save the money.
  
• Check your distributor is reasonably clean and nice and dry inside - spray in some WD40.
  
• Check all the earth straps to the engine block - if in doubt, replace the earth straps. A good earth is essentially.
  
• Unbolt the coil and clean up the bracket, make sure it's got a decent earth.
  

Try and figure out were it's going wrong:

• Pull the king lead off the dizzy and see if you get a decent spark onto a nearby bit of steel body metalwork - if the coil is in good nick you should have a pretty ferocious spark. Get someone else to turn the engine over on the starter and hold the lead in pliers with insulated handles... You can cut the fuel while doing this using the cutoff switch under the back of the passenger seat.
  
• Try sparking the king lead to the engine block - if the spark is noticeably worse than to the bodywork you've got a lousy earth.
  
• Now try the same with each plug lead - you'll probably find considerably less spark. If it's really feeble, suspect the dizzy cap.
  
• Check the ignition timing with a timing gun. LPG likes more advance at low revs, so you'll probably need to run a compromise a few degrees ahead of standard (8^o for your engine at idle - I ran 13^o advance which made it idle rough on petrol but fair on LPG).
  

So far as I could tell when I was running standard ignition the dizzy is the weak point - maybe mine was just shot, but even in the dry with everything in as good order as possible I lost a lot of spark across the dizzy. It's also the bit that doesn't like water...

[DC_]

Thanks for all the effort on that post, really do appreciate it as i feel i'm all alone on this with not knowing too much about the whole thing.

Update:-

Took her out a run last night to the park. Switched off, tried to restart and the starter motor wouldn't turn over.

Had to leave it there until i could get round this morning.

Gave the starter a bang to see if it would unjam, no luck. Gave the leads a wiggle to see if it was a connection, at first it didn't work. There wasn't even a click from the starter when i was turning the key.

Then i gave the leads another good wiggle and tried. I then turned the key and held it in position to start, whilst doing that, i activated the alarm immobiliser, then unactivated it, then the starter started to click in and turned over. Engine started up ok.

I am going to disconnect the motor and clean up all the connections,also been told to replace the spade connectors with crimp on ones.

Clean the male spade (on starter motor) and smear on vaseline. Any thoughts on this ?

[bofa4x4]

Gee me a fone laters Chas (DC)

Im off to get 'Lucys top noo.

speak soon after ye get the starter cleaned as we spoke aboot.

[DC_]

Gee me a fone laters Chas (DC)

Im off to get 'Lucys top noo.

speak soon after ye get the starter cleaned as we spoke aboot.

Howdy Wills,

Update:

Changed spark plugs (NGK)

Got Lucas leads

New dizzy cap.

V Power and redex treatment.

Checked connections to starter motor..........................BINGO!!!

Spade connection was hanging off and barely touching solinoid.

Connection now good and after changing all the leads ( someone who fitted the older ones actually had them on in the wrong order) and dizzy cap. She fired up ACE!!

Took a run up to GEMM 4x4 today to try and get an exhaust part. Never cut out once and ran great on LPG.

WIll do a service next weekend to make sure all filters are ok.

MAGIC!!