Angelo Sarti

To give you a brief history outline:

The Fairlane had a small engine fire due to a misfire in the system. The fire was located on the top of the intake manifold and according to the mechanic the engine was able to be gotten going again by just cleaning it and replacing the hose between the airflow meter and the manifold which had been damaged. ie the fire was small.

After getting the car back I replaced the old worn out engine with a reconditioned long motor. The installers fitted the same EFI hardware and sensors, non of this equipment was changed. After the installation, the PCV valve was replaced as the car was running very rough. With the new PCV valve the car runs at about 90% but still has some intermittent idle problems which are very annoying.

The symptoms are:

On start up the car idles OK. After driving for a few minutes and you stop at lights the idle will jump up and down from say 300 to 700 rpm, it may occasionally stall in this position. Continuing driving the car exhibits surges and periods of lack of power can be felt in the car. After a few further minutes of driving the car will operate normally. During extremely warm days (40degC) the car is less stable and the idle problems can be felt much more regularly.

To date I have taken the car to several mechanics and changed the following items without fixing the problems:

1. PCV Valve
2. Hall Sensor in dizzi
3. Ignition Coil
4. Ignition Module on dizzi

Can anyone suggest where to look next???

coach15

go to birdman auto in EPPING MELBOURNE

TopGhia

That's brilliant - what if he lives in Darwin?

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TopGhia

Fuel quality, are you using quality fuel? Most of these el cheapo places are awash with ethanol (one place tested had over 20%).
Bad fuel may be the cause.

Here is a site all about manifold vacuum tests, which is a good start for any diagnosis. I like the moving dials, wait a minute for it to load. (There are 2 pages in all)
http://www.users.bigpond.com/ergoff/vac1.htm

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snavy

exactly like me friends ZL! no idea what it is, we tried replacing a few things but didnt work.

Angelo Sarti

Thanks for the replies,

One thing I forgot to mention is that the car is on dual fuel and it does it worse on petrol than on gas.

Also I have heard that if you pull out the dipstick on the fairlane it will idle rougher due to the air intake?

My car idles rough whether the dipstick is in or not? any clues here?

AusXH

Sounds like a vacuum leak somewhere. Check the vacuum lines (small plastic colour coded pipes) that go to the EGR (the disc shaped thing on the top-rear end of the plenum that has a line running to the exhaust), the fuel pressure regulator (at the rear of the fuel rail) and to and from the vacuum switches mounted on the inlet maniold near the distributor.

Could also come from around the many intake manifold surfaces or around the rocker cover, the mechanic may have left a gasget out.

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