Renault clio 1.2 16v 2001 running problems

[teerak2uk]

hi Guys

got the above vehicle to hand at te moment that is proving to be a headache and any advice/idea are welcome so basically here it is


renault 1.2 16v starts and runs ok but after a few minues of driving starts to to stall at junctions and mil comes on rev it to 3000 it then clears and light goes off sometimes codes can be read and sometime there is`nt any but when read always shows the same.

manifold pressure sensor
downstream short to 12v

so had at hand the same car but 2003 model so swapped the two sensors but problem is still there so this is where the headache starts have racked my brain and the net and seems to be alot of these wth this problem and most seem to point at the engine loom so decided to swap the loom,manifold and throttle body complete then started it all seemed fine until the next morning and he problem came back with the same 2 codes

so checked live data and seems to downstream sensor was switching up and down but not very often so swapped it with the one from the good runner and was the same so swapped it back because the customer needed the good car back so put the problems car downstream sensor back in and now shows to be switching even more but no donor parts available so does anyone think it is possibe that all this is caued from a crap cat?


many thanks

[racin-snake]

what did you scan this with and do you have the codes ?

[teerak2uk]

Scanned with snap on modis and cant remember the codes but basically it was manifold pressure sensor and the other was downstream sensor (o2 sensor after cat)

[dafdiagnos]

does it start & run ok from warm or just from cold m8? it sounds temperature related

[racin-snake]

my thoughts too also map would cause a problem too after warmup as the inj time would drop making a weaker mixture for the hot engine
so codes definition would maybe have made the difference
also air volume of overrun and sevo draw would drop the mixture further hence the cut out
and throwing the 02 sensor code on open loop
any chance exact code descriptions or some live data of tps and map at idle and wot ?

[BazT]

Hi The map sensor code would probably be triggered by the stalling (loss of manifold pressure) The second code downstream sensor would not cause the engine to stall. I would try cleaning the throttle body and re set the throttle adoptions.

BazT

[Albanais]

Hi The map sensor code would probably be triggered by the stalling (loss of manifold pressure) The second code downstream sensor would not cause the engine to stall. I would try cleaning the throttle body and re set the throttle adoptions.

BazT

Your diagnosis are correct mate but I have one idea mor to add. If the engine has a motorized throttle I sugest you for first to repair the earth point on the gearbox the nut may be loosen, then you make re initialising of the motorized throttle.Earth point has caused me big head aches in past, fix the earth point then deal other problems.
Cheers

[teerak2uk]

car is better when cold as for throttle body i changed the whole intake manifold complete with throttle body and engine loom from a good runner so no probs there as for earths have been through them and all check out ok so going to connect my can clip in the morning and see what it shows on a cat test

[Albanais]

car is better when cold as for throttle body i changed the whole intake manifold complete with throttle body and engine loom from a good runner so no probs there as for earths have been through them and all check out ok so going to connect my can clip in the morning and see what it shows on a cat test

The aim is not changing every thing, I asked you if the throttle is motorized or not, if it is motorized then make re-initializing of the throttle through the injection ecu when the car is cold, check the earth cable as well.

[teerak2uk]

The aim is not changing every thing, I asked you if the throttle is motorized or not, if it is motorized then make re-initializing of the throttle through the injection ecu when the car is cold, check the earth cable as well.

but when you have access to a good running one then sometimes is easier to eliminate the fault by changing parts from a good running one and yes it does have a motorized throttle, all earths are good

just done a cat test because of the downstream o2 sensor continually switching and cat is now running at 99% effiency so maybe i have an issue with a temp sensor

[rideon]

Just a thought...when the car is "broken" check live data: 1.manifold pressure 2.atmospheric pressure and report back

[rideon]

Still think is a pressure sensor,there are 2 in this car if i remember,one is in manifold the other is in ecu,easiest thing to do is to replace MAP.
If I'm right, the spark plugs should be black and smoked

[bo0st]

common problems in 1,2 16V renault engines:
cylinder head gasket - oil leakage
injector faulty ( electrically or mechanically) - missfire
ignition module - missfire
manifold silicone gasket bad assembled from fabric - warm missfire or low power
rarely MAP (pressure sensor) - misfire or low power and rich mixture

check valve clearance if you dont find any failure!

[teerak2uk]

wont be map sensor as i had previously swapped it from a good running car

after noticing on live data that the downstream sensor (sensor after cat) is continually switching giving concern this could be a bad cat or on its way out so have connected my can clip and ran a cat tested procedure basically tells you to start wait until warmed up, 2 cycles of engine cooling fan then rev the vehicle to 3000rpm for 1 minute then idle then 4500rpm for 1minute from what i recal and then monitors the temp of the cat and give you a percentage of efficiency (mine was 99%) so after replaced the temp sensor as the can be a nightmare sometimes and dont cost that much now back on live data and downstream seems to be ok even though i have seen it switch but very rare so time will tell but i think if it cames back then it may be time for a cat

[racin-snake]

try a tem reading with an ir temp guage of the ftont and rear of the cat front and rear should be within 50 degrees or less of each other
easy test and also make sure there are no air leaks or a evap unit pipe snapped