Falcon's Bargain Basement Motoring

[CitroJim]

Hi Neil, good to see you on here

[MattBLancs]

Thanks for your post Matt. Hesitation on acceleration surely has happened at some time or other for most car drivers. I hope I have described the experience with the Clio well enough to help nail the cause down. Don't think the Clio had seen 5,000 rpm in its lifetime before my pre-MOT Italian tune-up activity. Really makes a decent sporty noise and a fun drive.

Neil

Hi Neil! Sorry to be clear, I thought your description was good, nice and clear how it's (mis)behaving.

Only intending to give a bit of "thinking aloud" on the theories posted

On MAP sensor, think they can get a bit gummy too (depending on how near they are to the PCV connection I guess??) so might be worth putting that on the Give It A Clean suggestions list.

I'd not bother cleaning entire inlet manifold, just the throttle body bit.

[NewcastleFalcon]

Hi Neil, good to see you on here

Thanks Jim, just bringing a selfish good old car fix-it puzzle to the finest fix-it brains I know!

Any tales of acceleration hesitation and solution from the Citro Jim archive. Its just like the old fashioned dirty petrol/water in petrol loss of power then a surge back to normal with a continued use of the heavy right foot!

Neil

[NewcastleFalcon]

Hi Neil! Sorry to be clear, I thought your description was good, nice and clear how it's (mis)behaving.

Only intending to give a bit of "thinking aloud" on the theories posted

On MAP sensor, think they can get a bit gummy too (depending on how near they are to the PCV connection I guess??) so might be worth putting that on the Give It A Clean suggestions list.

I'd not bother cleaning entire inlet manifold, just the throttle body bit.

Very grateful for your input Matt. The Inlet Manifold is a bit of a cumbersome beast in the finest plastic, sitting on top of the engine snaking over from back to front with its four "arms" before the fuel rail and 4 injectors mount into it at the front. Plenty of scope for a bit of leakage at its gaskets.

Neil

[Paul-R]

Crikey, that photo is verging on an AI nonsense nightmare creation.

[NewcastleFalcon]

The throttle body is underneath all that plastic as shown in this vid which I have started at the point where the Inlet manifold is lifted off to reveal the throttle body!



Neil

[MattBLancs]

The throttle body is underneath all that plastic as shown in this vid which I have started at the point where the Inlet manifold is lifted off to reveal the throttle body!



Neil

Oh wow, wasn't expecting that! How odd!

Is the air filter under that big assembly (inlet manifold off for a filter change!? Surely not) or is that throttle body pulling from a large plenum and the air filter is elsewhere?

In any case, agree there looks to be lots of potential leak paths there

[Rp0thejester]

I would definitely be checking the maf/map sensor first as had mine faulter once with no acceleration then lifted off accelerator and basically stamped on it then acceleration returned to normal. Also it would rev freely when stationary but only affected by actual driving. Surely the cheapest fix as well.

[NewcastleFalcon]

Oh wow, wasn't expecting that! How odd!

Is the air filter under that big assembly (inlet manifold off for a filter change!? Surely not) or is that throttle body pulling from a large plenum and the air filter is elsewhere?

In any case, agree there looks to be lots of potential leak paths there

Air filter and MAP sensor as indicated in this photo.

Another odd Renault thing the Renault 1.2 16V D4f engine doesn't have a PCV valve as such. The oil breather is actually part of the rocker cover,
and discharges into the air filter housing according to the Renault Forums https://www.renaultforums.co.uk/threads ... se.114424/

Neil

[bobins]

......in that case, I'd be tempted to remove the whole plastic intake abomination, along with the air filter housing, and put them all in the dishwasher for a quick clean whilst no one is looking

[Rp0thejester]

Isuzu 1.7 DTI engines have an oil cooler which leaks into the coolant, most think it's a head gasket issue so sell them cheap, it's not, but a Finish dishwasher tablet in the the expansion tank keeps the car running perfect!! Proper bargain basement.

[MattBLancs]

Isuzu 1.7 DTI engines have an oil cooler which leaks into the coolant, most think it's a head gasket issue so sell them cheap, it's not, but a Finish dishwasher tablet in the the expansion tank keeps the car running perfect!! Proper bargain basement.

Weirdly I was reading about cooling system flushing recently and stumbled on the "dishwasher powder / tablet trick" apparently works ok though lots of folks very worried about it's affect on aluminium. Some suggestions that biological washing powder (i.e. clothes washing powder, not dishwasher stuff) is supposedly better.

PSA engines can do the oil in coolant via oil cooler ** issue too I believe (actually ** oil to coolant heat exchanger, normally sat under the oil filter on older engines)

[bobins]

I've used dishwasher powder to clean a few carbs in the past, but I absolutely made sure to thoroughly wash them in clean water as soon as they'd come up sparkling.

[Rp0thejester]

As long as it doesn't have a foaming action everything should be okay, as for worried about aluminium, surely it would be okay if it's safe on porcelain and rubber and tin etc

[NewcastleFalcon]

I think a new MAP sensor at £14 is an intervention worth doing as mentioned by Ryan. Here's a vid of a bloke testing his MAP on my very engine with a multimeter and a safety pin. The MAP sensor is very poorly mechanically connected to the top of the air intake. It is a push fit into a hole, it has an O-ring but there is no bolting down to prevent it moving, and is is retained only by that push fit and the o-ring.

Mostly for my own reference...Renault in their wisdom entombed the ECU in an anti-theft, anti-tamper loosely fitting metal enclosure. In Clio's this is notorious for jiggling up and down on the vital wiring loom as it enters the main ECU connector, often damaging the bundle of thin wires going to the main ECU connector. That turned out to be the particular problem fixed in the video. Probably my rudimentary code reader, but I have never had the P0105 DTC , nor any other MAP related or otherwise. The only DTC's are P0130/P0170 thrown out by the Pre-Cat O2 Sensor.

Today's little Italian tune up was done without the air filter for no particular logical reason other than to maximise the flow of air into the intake and see how that affected the stuttering. I would say it improved things marginally. It didn't throw up an EML at any stage, but at no time was there one of those serious stuttering episodes, although there was some discernible hesitation at times, but maybe not severe enough to throw up the light or the P0130 code.



Neil