Hunting on idle

[mattv6]

Hi,

I've changed spark plugs, new ht leads, got rid of spark plug extenders, fitted new dizzy cap and rotar arm, cleaned carb and also Idle screws but..... My 5 is still hunting quite badly on idle.

Is there a restrictor in one of the small pipes? Any pics of which pipe?

Any other ideas would be greatly received as its quite bad and is cutting out when clutch is in.

Cheers,

Matt,

 

[read6737]

Check there is no air leak on the vac advance and retard pipe.
Ensure the TDC sensor is clean and not loose.
Check the Timing.
Check fuel mix.

I remember in the late 80s having a hunting problem many times.
The most common reason was fuel mix went off quickly so I bought a snap-on gas analiser.
I also had a vacuum air leak and the TDC sensor became loose.
Not all at the same time though.
The most frequent starting problem was condensation in the dizzy cap.

 

[mattv6]

Cheers mate. Being a novice with this car.

Where is the vac advance and retard pipe, and tdc sensor? - any engine pics with them on?

Is there a mixture screw on the carb?

Thanks in advance.

 

[read6737]

Best get a Haynes manual of ebay.
See scan.
Vacuum pipe is a thin tube from the round disc on the Renix unit.
There is a screw on carb best get a garage to set it or at least some one with a gas Analiser.

It is 20 years since I last worked on GD turbo.
Now I have just got 3 again so the memories are coming back with a little prompt.

 

[mattv6]

Looked through Haynes and found tdc sensor.
Also said it could be related to the mixture so will check that.

Still couldn't find retard and vac advance pipe though sorry - are they in the Haynes?

Would it be anything to do with the air cleaner thermostat and egr?

 

[read6737]

The advance retard pipe is in the scan on right side below renix..
On the renix unit round disc (vacuum sensor item C) .with pipe and a circle magnifying the tube pipe,

 

[mattv6]

The advance retard pipe is in the scan on right side below renix..
On the renix unit round disc (vacuum sensor item C) .with pipe and a circle magnifying the tube pipe,

You're a star - thanks mate

Will try this tomorrow

 

[mattv6]

Update.

1. Cleaned the renix connectors
2. Checked the vacuum pipe - seemed fine but had no clamps on pipes. Going to get new pipe and clamp it to vacuum
3. Adjusted mixture screw - it was fully wound in. Made a little bit of difference but still hunting. Are there 2 mixture screws on the weber?

So.....still hunting.

What else an I try?

Runs brilliantly now apart from this issue.
Cheers for help.

 

[sparkie]

checked O rings on turbo boost pipe?

 

[mattv6]

checked O rings on turbo boost pipe?

Posting on two forums here
No not checked them.
Where are they sorry pal?

 

[mattv6]

The advance retard pipe is in the scan on right side below renix..
On the renix unit round disc (vacuum sensor item C) .with pipe and a circle magnifying the tube pipe,

Should there be something in the tube then or just the tube itself? I put a new pipe,on today with clamps.

Changed some of the old tubes from actuator to carb - they were knacked.

Checked o rings on plenum to inlet - seemed in ok condition. Can you get new ones from Renault still?
Part number please?

Also on p. 110 of the Haynes manual it shows a small calibrated jet in the t piece.
My t piece doesn't have this in there.....?! Should it there and might that be causing the idle problem?

Haven't driven it yet to see if it's made any difference though.

 

[mrdini]

I think from memory it's worth checking for leaks around the carb/ inlet manifold and especially the condition of your hose off your break cylinder unit to carb or is it inlet manifold the thick long hose! , you can run the car and spray some easy start around areas to note any change in idle to find leaks

 

[mattv6]

Cool will do.

Is there a calibrated jet as I don't seem to have one in my tpiece?!