Clio 172 2002 running like a scooby

[nicknak2010]

Hey gents

New member here just looking for some quick help on my clio

Its a 172 2002

Randomly driving along casually and its started dropping a cylinder (sounded like a scooby) i unplugged the far right injector whilst running and nothing happened, i unlplugged the 3 other injectors each in turn and it ran worse so im assuming its an injector problem

Just wanted aome advice before i take it to a garage and get my a***e handed to me lol

 

[Ol’ Tarby]

Yeah it's probably the injector gone. Euro car parts sell them and are an easy swap. If you know your way round a spanner there's no need take it to a garage mate

 

[StrongboW]

Hey gents

New member here just looking for some quick help on my clio

Its a 172 2002

Randomly driving along casually and its started dropping a cylinder (sounded like a scooby) i unplugged the far right injector whilst running and nothing happened, i unlplugged the 3 other injectors each in turn and it ran worse so im assuming its an injector problem

Just wanted aome advice before i take it to a garage and get my a***e handed to me lol

It could be a HT Lead not firing that cylinder spark plug. Have you looked to see if the injector is firing?

You know what cylinder it is so order I would go is. HT leads + a set of plugs if there abit shabby. If that doesn't work try a coil pack can always be sent back if that's not the problem then go for injector. That's my opinion mate.

 

[nicknak2010]

I dont know how to see if the injector is firing tbh, i know the plugs are maybe only a year and a half old, how can you check Ht leads, and to pull off the ht leads whilst running you can see spark so that would rule out plugs right?

 

[dane0]

Before buying new leads plugs and possibly a coil check them. Run the car and hold the plug/lead with something that won't give you a shock and you should see it spark and generally you can hear it too. Sometimes I put it near the inlet manifold and you can see it jump across, I don't know if it's safe for the car but I've never ever had a problem and I usually try this.

If there is no spark it could be leads or pack or plugs.
Now swap far right lead (far right we will call FR) with another and see if it sparks with the original plug from the FR as well as the one that was on it. If both plugs still don't spark it's likely to be the coil pack as you have now tried a lead and plug that has worked in say cylinder 3(or which ever cylinder you took the spare one from).
If one plug works and one doesn't it's the plug so remember which plug was the original one. Make sure the lead is plugged in the FR cylinder coil pack hole to rule pack out. This shows that the coil pack is firing on the right hole.
So if neither plug works on the FR cylinder pack hole now try both leads in the coil pack hole (say cylinder 3 again) that was working and this will determine which lead is not working as we know that 3 works.

You can do these in any order so the rule is basically process of elimination so just make sure you do it all properly and think about it because if you mess one up you'll really think you got a big problem lol


With the injector out you should easily see if that's working while the engines running.

 

[nicknak2010]

Thanks for the input gents, took it to the garage they found it was a ht lead, thats was crushed although its ran fine for a year its suddenly failed on me, it now runs as it was before, although wilst we are on the subject it has never ran properly let me describe this as best as i can

It misses a beat when running so its a bit 'burbully' like a rally car or one thats been cammed, when car is cold and you set off you find the when trying to hold speed (30mph) the power will be not enough and car will begin to slow yet put accelerator down slightest amount and the power is a bit of a jump and goes over 30mph, when warm this problem is gone and is smooth enough to drive fine, although its not super bad when cold its noticeable to the driver.

Another way to say this is power is variable when at constant pressure of throttle, so when pulling away there is a chance of stalling at what would normally be an ok amount of throttle it can stall because revs seem to be a little bit up down on a few beats.

Dont mistake this for a 'waving rev range whilst idle' rev counter stays constant but misses a beat

Btw its had all new ht leads now, plus all new spark plugs a while ago, one new injector, and also paperwork shows for a similar running problem whilst was sorted by a garage and had a replaced loom

Also i belive it needs a head gasket although i didnt think this would effect its running but thought id mention it

 

[j4mes-c]

These aren't the best runners when stone cold. Mine hesitates and holds back slightly for 30sec when first driven cold then suddenly is fine.

 

[Ol’ Tarby]

Thanks for the input gents, took it to the garage they found it was a ht lead, thats was crushed although its ran fine for a year its suddenly failed on me, it now runs as it was before, although wilst we are on the subject it has never ran properly let me describe this as best as i can

It misses a beat when running so its a bit 'burbully' like a rally car or one thats been cammed, when car is cold and you set off you find the when trying to hold speed (30mph) the power will be not enough and car will begin to slow yet put accelerator down slightest amount and the power is a bit of a jump and goes over 30mph, when warm this problem is gone and is smooth enough to drive fine, although its not super bad when cold its noticeable to the driver.

Another way to say this is power is variable when at constant pressure of throttle, so when pulling away there is a chance of stalling at what would normally be an ok amount of throttle it can stall because revs seem to be a little bit up down on a few beats.

Dont mistake this for a 'waving rev range whilst idle' rev counter stays constant but misses a beat

Btw its had all new ht leads now, plus all new spark plugs a while ago, one new injector, and also paperwork shows for a similar running problem whilst was sorted by a garage and had a replaced loom

Also i belive it needs a head gasket although i didnt think this would effect its running but thought id mention it

Cold running issues are a pretty much standard for 172s mate. A remap sorts them out completely.

Both mine were awful until mapped

 

[dane0]

Head could case a problem depending on where it's split as you could be losing cylinder pressure in say your water resistant tank/radiator so therefore may not have enough pressure to ignite it, and as it heads up the gap/leak may get tighter. But as said before they are a really lumpy runner especially when cold, mine backfires and pops if I engine break cold even around 2k revs and once heats up its unbelievably smooth