D1 Injected Gas Troubles

[Vinnie]

Hello All,

Is anyone able to recommend someone in Melbourne's Southern Suburbs that is good at diagnosing and fixing problems with injected gas? Unfortunately some time ago my car's alternator decided that it didn't like muddy water on a trip. I have had the alternator replaced, but ever since it has been going it won't run properly on gas (it hesitates like it's not getting gas occasionally and at low revs under load it sounds like it's not firing on all cylinders). The system is still under warranty (just) and typical of some companies they are just trying to pass the buck and blame the car and insist the gas is OK. I have replaced the coil, coil lead, have had the engine compression and leak tested, distributor re-built, all done because that's what the gas company told me was wrong with the car and it still runs like crap. I can't be bothered fighting them because I am just over it and I need the car fixed so I can use it again for work and play. Just want some ideas on a good honest gas mechanic who works on injected gas systems.

Cheers,

Vinnie

[bee utey]

First of all LPG injection systems are very brand specific and you can't tune one unless you have the software to suit that model. So you need to find someone who works with your specific system.

Secondarily what ignition advance, spark plugs heat range and gap are you running? Your plug gaps should be around 0.7mm not the factory stock 1.1mm. Lean mixtures will not run well on stock ignition settings.

[Vinnie]

My system is a BRC (made by Impco). All the settings are right, it was running fine and since a breakdown won't do the gas thing properly, but is fine on petrol. As said just sick of being stuffed around by a company that doesn't want to honor it's warranty. I guess I'll just have to keep searching.

Cheers,

Vinnie

[ozscott]

Fine on petrol isn't necessarily the defining point for lpg system failure because of the more demanding spark that they require. Brc is a very good gas company that sells good gear so why not ring their head office and give them the low down and see what they recommend in terms of service agents.

Cheers

[bee utey]

Impco BRC is good stuff so you have either 1. a sticking injector or 2. weak ignition as ozscott says. I won't say "Lucas Ignition module partial failure" is the most common cause of weak ignition as you have already convinced yourself it is all OK. A Bosch ignition module conversion will alleviate a weak spark issue. I do dozens of these as it is the most common failure problem with D1s on gas.

http://www.aulro.com/afvb/technical-chatter/96950-lucas-ignition-amplifier-replacement-bosch-024-a.html

A sticking injector would be traceable by shorting out individual plugs until you find the cylinder that doesn't slow down the idle speed. Carby cleaner can be forced backwards through the injectors by removing both the inlet and outlet hoses and blowing some carby cleaner back through the injector with compressed air. Not commonly a problem with BRC injectors but not unheard of.

[ozscott]

Impco BRC is good stuff so you have either 1. a sticking injector or 2. weak ignition as ozscott says. I won't say "Lucas Ignition module partial failure" is the most common cause of weak ignition as you have already convinced yourself it is all OK. A Bosch ignition module conversion will alleviate a weak spark issue. I do dozens of these as it is the most common failure problem with D1s on gas.

http://www.aulro.com/afvb/technical-chatter/96950-lucas-ignition-amplifier-replacement-bosch-024-a.html

A sticking injector would be traceable by shorting out individual plugs until you find the cylinder that doesn't slow down the idle speed. Carby cleaner can be forced backwards through the injectors by removing both the inlet and outlet hoses and blowing some carby cleaner back through the injector with compressed air. Not commonly a problem with BRC injectors but not unheard of.

Good advice there. I had to go a step further on my D1 (mixer) with a Performance Ignitions Stryker dizzy which is part ford and part holden V8 with holden V8 cap.