clio with a misfire at 3k rpm

Newbie Joined: 06 Aug 2005 Posts: 4

Been looking for an active renault forum for ages hoping to get some ideas as to what could be wrong with my car.

I've got a 1.4 93 reg clio that had the head rebuilt after a blown gasket a few months back. Since then there has been a misfire which has got worse recently.

The misfire appears to be worse in damp weather so tried replacing the HT leads, dsitributor and rotor arm and then the spark plugs recently, but that has made the misfire worse.

The misfire occurs consistently at 3000 rpm and is much more noticeable in 1st and 2nd gear, but still does it in 5th sometimes. When it happens (in 1st and 2nd) it feels like I've quickly let go of the accelerator and then jammed my foot back down. The car quite happily accelerates up to the rev limiter and the misfire doesn't appear to happen much when accelerating hard.

Just wondering if anybody had any ideas as to where to start looking at this problem.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

could be a lot of things.

clean the crank angle sensor which is on the bellhousing, these get covered in clutch particles and it can upset them at certain revs, you can get intresting voltage spikes from them which can shut the ECU down momentarily.

But check all the vacuum pipes etc make sure they are not dicky and go round and break and re-make all the connections, these can play up.

Newbie Joined: 06 Aug 2005 Posts: 4

Ok, thanks very much, I'll give those a go over the next few days and see if it makes any difference.

Cheers for your time, much appreciated

Site Subscriber Joined: 29 Jan 2005 Posts: 1108

That could be the throttle position sensor maybe? I had same problem on my R19, and it happened at the exact same revs everytime. Although on mine it was about 4,500rpm. Like everytime I went to overtake or accelerate hard, I had to keep me eye on the rev counter and make sure I didn't rev that high otherwise it would missfire like a bitch. Well, I dunno if missfire is the correct term. Guy at renault was telling me that when I got to 4,500rpm, cuz my throttle position sensor was not able to go higher than that, my fuel supply was being cut off at that point or something. Or not enough fuel at that point. Cuz throttle position sensor moves with the throttle and pumps the right amount of fuel for how hard you are accelerating I think? And so mine was not able to go high enough for me to rev above 4,500rpm or something. Can't remember exactly what he said, but it made perfect sense.

Anyway, diagnostic check at renault to discover the sensor was faulty, having new sensor from them and fitting of it, and also another check to check it was all okay........all came to Â£117, which I thought was legend! So now when I'm overtakin I don't have to constantly check the rev counter, I can just put me foot down and go Very Happy

much better!

Newbie Joined: 06 Aug 2005 Posts: 4

Yeah misfire it probably not the correct term, it's especially noticeable on hills it feels like the engine isn't firing at all for a few seconds and then kicks in again rapidly. Which on hills is a bit bad!

I can rev above 3000 quite happily so ... dunno, I'll go with the free checking things options first mentioned by Chris and then take things from there.

Again, cheers for your time

Site Subscriber Joined: 29 Jan 2005 Posts: 1108

Yeah, Chris knows a lot more than me! Very Happy

Newbie Joined: 06 Aug 2005 Posts: 4

Cleaned the crank angle sensor and it's all good now, no more misfiring! Very Happy

Thank you so very very much!

Spammer Joined: 27 Jul 2004 Posts: 5717

chris ,is it safe to spray engine degressant or use a pressure washer once the crank angle sensor is out to clean the area ???

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

aye, no probs shacks.

mellow glad its sorted, send the Â£5billion cheque to the usual address! Laughing

Spammer Joined: 27 Jul 2004 Posts: 5717

nice one