Problems With My AU Dual Fuel

autickfordfairmont · 16-10-2007, 10:40 AM

Hey guys,

I have an issue with my AU 6cyl Fairmont - Both Petrol & Gas problems.

I have had it converted to gas for a few months now, and I have been having a problem when its running on fuel & gas. The gas system is a Landi Renzo injected system.

It was running like a dog recently so I changed leads, which helped then changed to Gas Plugs, Cleaned air filter and that seemed to fix most of the problems.

So my problems are as follows:

1) On a cold start up the car will start, but almost stall, just ticking over coughing and farting for around 10secs before the idle picks up and grabs control of it. I have cleaned the ISC and it didn't help.

2) Running on Petrol my car has a major Flat spot from around 2000rpm to 3000rpm. When driving at highway speeds just over 2000rpm you can feel the car hunting, if you accellerate nothing happens except for more hunting untill it drops down a gear, revs above 3000rpm and then she flies. At high rpm it hammers, no problems, its just between 2000rpm & 3000rpm it has the issue. Im thinking fuel line related as It doesnt do it on gas. They fuel filter is not that old and i have chucked a couple of bottles of injector cleaner through her. I will change the Fuel filter this weekend to see if that helps but this seems to be different to when i have had a block filter in the past.

3) My third problem is gas related. As said it was only recently (5 months ago) that i had gas installed. The car has a major miss down low on gas, if you take off from an intersection or light and hit the accelerator quickly she will cough and fart around , if you hold you foot on the brake, with small acceleration (to bring revs up slightly) it will take off fine and runs great.

4) Yet again gas related, every now and then on gas (im running an injected settup) after i give it a boot full, like on the entry ramp to the highway, it wont rev out past about 3600rpm, yet again it coughs and splutters about, if i switch to fuel for a while then change back it seems to fix the problem. Im new to gas so could this be a freezing up issue or something????

Sorry for the long post.

Cheers guys

Col.

**Mechan1k** · 16-10-2007, 04:37 PM

Coil pack on the way out ... it's the only thing that really fits all things.

It can cause the odd occasional hard start ... and it can cause low-down misssing on LPG ... but not so noticeable on the petrol side of things either.

autickfordfairmont · 17-10-2007, 09:52 AM

Bugger. What about the no power between 2000rpm-3000rpm, would it cause that aswell???

sly · 17-10-2007, 11:03 AM

I'm having similar but slightly different probs - cold starts on gas same as above, but rough idle & big flat spot just off idle under light throttle, goes OK if I get up it.

Have cleaned throttle body, IAC and repaired hole in snorkel behind balance pipe. The car has symptoms of a vacuum leak as well (ventilation control issues), will be checking this out v soon. I suspect this may be causing my probs as vacuum would normally be high at idle & light throttle & not need much to upset.

Any suggestions as to best place to hook up a vacuum gauge? Most accessible is around PCV and vapour canister bit I'd prefer not to interfere with them. What's the thing that looks like a dashpot at the rear of the manifold near where the brake booster vac line comes out?