197: Lumpy Idle (mostly when cold)

[av4625]

When I start the car it goes to normal revs, then all of a sudden it will drop to about 600rpm. It snuffels around and shakes a bit for 10-15 seconds then bounces back to normal. It can do this a few times over and over. More when cold but does happen if just idling for a while when hot.

The belts have been done recently and timing was checked.
I put on a new genuine camshaft sensor as the previous had gone and I was away down on power.
I removed the throttle body, PCV valve and hose going to the PCV valve and cleaned them. PCV was clean (first time I done it to the car since buying it) throttle body was a little dirty.
New ramair panel filter.
As far as I can tell the flexi's on the manifold are fine. There is a scorpion non res catback on the car since I bought it too.
All four engine mounts have been powerflexed, shouldn't make a difference unless it doesn't like the shakes.
I think the thermostat is opening too early and over cooling so I ordered a new 75 degree one.

I don't remember it doing this when I bought the car, can't remember when it started. Runs fine, I use the car for sprints. When lining up it does the weird idle and its annoying.
Anything I could look into to sort it?

 

[turkie172]

I had that with the 172 Clio and I never got to the bottom of the problem the first 10 - 15sec when cold on the 197 I think is a pre programed part of the map then it looks at the sensors this is normally when you get the flat spot or kangarooing people talk about because at the front door in the morning if I start the car and move off right away at the same part of the road you seem to loose power if you lift your foot off and bring it back gently it picks up again and no problems for the rest of the day I'm guessing it is a transition in the map for cold start. I would think the exhaust is not helping but check the plugs and plug wells the other thing to check would be the gearbox sensor throwing out slightly off signals.

 

[av4625]

Forgot to mention i put new OEM plugs in too. My car does kangaroo really badly. Like throws you around inside the car.
I also have the MAF sensor cable tied down for what its worth

The second from the left plug well does seem a bit damp at times. Cant see the windscreen washers leaking

 

[turkie172]

Well what I'm talking about is like slowing acceleration almost like running out of petrol put the old plugs back in if they are genuine some car places give you plugs for a 172 the 197 plugs are different and check the plug gaps again the exhaust will not be helping things if its non resonated it will need mapped especially if the cat has been deleted I have had the kangaroo before its like the traction control is messed up it's like you don't know how to pull away rather than being thrown around.

 

[av4625]

Oh the plugs are the right ones. Got them from opie oils, checked the part number and everything. Both cats are still there. If i drive off straight away, when going easy in second gear it jumps about, have to clutch it to stop.

 

[Dean Cohen]

Oh the plugs are the right ones. Got them from opie oils, checked the part number and everything. Both cats are still there. If i drive off straight away, when going easy in second gear it jumps about, have to clutch it to stop.

From experience the kangarooing in 1st and 2nd seemed to be the MAF sensor for me: See here for fix: https://clio197.net/threads/possible-fix-for-the-dreaded-flat-spot.38297/page-19#post-685870
did that trick last night and seems to have cured my issues