1.9 Intermittent Misfire

[Charlie 0 1 Cars]

Hi guys, new poster here - I've had a look at the numerous posts on intermittent misfiring, but was hoping to describe my symptoms and get a personalised response.

 

My 205 has always had a dodgy idle, as in ready to stall after blipping the throttle and sometimes cutting out completely.

 

After a bleed screw failure (which I then had to tap out and replace with an m5 bolt and dowty washer) I took the opportunity to replace the afm, with great success to the idle.

 

After an initial cylinder down due to water filling the plug hole, I had the car idling well, with none of the previous idling issues.

 

The problem I have is that the car now misfires through the reviews range, with intermittent periods where it's OK.

 

I've checked the spark at idle, and they're all good and strong. I have cleaned up and checked the distributor and arm.

 

I'm kind of leaning towards the leads having had it, bit was wondering if you guys could think of anything else?

 

Thanks in advance,

Charlie

[steve@cornwall 100]

If you suspect the leads and they are either elderly or of unknown age why not replace anyway? Likewise with plugs, rotor arm and dizzy cap. Good idea to keep spares of these too as not always available off the shelf nowadays, so the old ones can get you out of trouble later on too. Dried out heat dispersant paste behind the ignition amp is also a likely culprit of various misfires, and a spare amp is always in my car too.

 

So basically change service items if servicing isn't up to date before fault finding

[Charlie 0 1 Cars]

OK thanks, I will try that first, and come back with the results.

 

Cheers,

Charlie

[2-Pugs 57]

I had a random misfire recently that turned out to be the distributor cap. As Steve said, id also recommend replacing plugs, leads, cap & arm, unless you know they have been recently renewed. It will always be money well spent!

[Telf 224 2 Cars]

theres a good few 205 owners around the Suffolk area. I'm in Ipswich. If your in the area I can have a look at it if you have no luck

[Charlie 0 1 Cars]

Thanks for the advice and offers of help guys. My ignition amplifier module came today so I'll fit tomorrow and see what happens.

 

Thanks again,

Charlie

[Charlie 0 1 Cars]

Hi guys!

 

Soooooo I've changed the ignition module, still no joy.

 

I checked continuity on all the leads and they're good, even when hot. I will try replacing them but I forgot to order some.

 

I changed the distributor cap and the arm, which hasn't helped.

 

I noticed that the vacuum advance hose has split, so I'll replace that - do you think that might have an effect?

 

Also, the dipstick wasn't sealing so I've ordered another one of those!

 

Poor old car. It'll all be new by the time I'm done!

 

Charlie

[steve@cornwall 100]

It's not the continuity of the leads at issue, it's breakdown of the insulation leading to short circuits.Sometimes if you run it with the bonnet up in the dark in damp conditions you can see a little blue lightshow going on.

[Telf 224 2 Cars]

What steve says !

[2-Pugs 57]

Also when you test them with a meter you'll get a different to result to what happens when there's a ton of voltage and current passing through them, which as the other guys say causes a high resistance which you won't necessarily pick up using a DMM. Worth getting a new set still I'd say :-)

[toolie72 67 1 Cars]

Mine had issues a few years ago (mind you it always has "issues")

Car would be fine for days even weeks then it would misfire-sometimes just holding it wide open (whilst looking for the rozzers!!) would sort it, other times it was plugs out and clean them-in the end I binned plugs and leads and hey presto-sorted

[Charlie 0 1 Cars]

OK thanks guys - all new gear is getting here tomorrow!

 

I've got another question, that hopefully doesn't need me to start another topic - I found a brown connector unplugged, just loitering under the expansion tank.

 

It looks like it runs to the gearbox behind the engine, but I can't see where it's supposed to be plugged in. Any guesses?

 

Charlie

[jackherer 543]

It's intended for a diagnostic/testing device that Peugeot dealers had about twenty five years ago. It should be clipped onto the cam cover IIRC.

[Charlie 0 1 Cars]

Thanks! Mystery solved.

[Charlie 0 1 Cars]

So I changed the leads today and it's now perfect, other than some slight hunting on idle with the lights on - which having read the forums would appear to be the alternator?

 

Thanks for all your patience,

 

Charlie

[steve@cornwall 100]

With the engine idling and the radio at a reasonable volume, flash the headlights and see if the radio turns off. Always seems an early warning of alternator dying.

[Charlie 0 1 Cars]

So after the radiator blanking plug let go spectacularly, I ripped the earth out of the engine bay fuse box whilst removing everything to replace the radiator.

 

It turns out that the earth was pretty much shot, only a couple of mm was still intact. I've crimped a new connector on and all is good now.