After cleaning out my throttle body I think I've developed an engine misfire. It only seems to do it a low revs in low gears i.e 2nd & 3rd.

I'm not even sure what a misfire feels like so I'm not entirely sure its that... it sort of jumps/lurches slightly, I only really notice it when in low gears at low revs.

It's quite annoying. Does anyone know if that does sound like a misfire? I'm sure it wasn't doing it before I cleaned the throttle body.

Edited 12 March, 200917 yr by mrtank

OK so just checked, it's misfiring at idle. It seems to be cylinder No1. I unlpugged the ht leads from the dizzy whilst runnning (1 at a time) and unplugging the number one lead doesn't make a difference to the car, so i'm guessing it's either dodgy No1 lead or spark plug.

I need to take the car on a 100+ mile trip tomorrow, will it be OK???

Still no replys

Can the temp sender cause misfires?

Change the plugs!

I wouldn't drive it very far until it's fixed.

Change the plugs!

I wouldn't drive it very far until it's fixed.

Yeah... I'm more thinking it's a dodgy lead. I went to try and swap the leads to see if it changed the misfire to a diff cylinder but didn't realise the leads were all different lengths, and obvioulsy none of the other will reach the number 1 spark plug.

I guess I could try changing the spark plugs over to see if that swaps the misfire to a new cylinder, I'll do that tomorrow.

Also just been out now in the dark to see if I could see any arcing but couldn't; so that didn't help me any.

It doesn't misfire at higher revs only at idle so I'm thinking it should be OK to drive with it.

Does anyone have any ideas on whats the most likely thing to be causing it? Only does it at idle/no revs, and I'm pretty sure it wasn't doing it before I cleaned the throttle body. Also I changed my thermostat housing for one from a scrappy recently; it still had a temp sensor in it, and I just left it in when fitting the housing, I just wondered if anyone knew if the temp sensor can cause misfiring?

Edited 13 March, 200917 yr by mrtank

Someone must have some ideas:

Does anyone have any ideas on whats the most likely thing to be causing it? Only does it at idle/no revs, and I'm pretty sure it wasn't doing it before I cleaned the throttle body. Also I changed my thermostat housing for one from a scrappy recently; it still had a temp sensor in it, and I just left it in when fitting the housing, I just wondered if anyone knew if the temp sensor can cause misfiring?

I would buy a new set of leads. My car decided to burn a HT lead on 7pm christmas eve! Needless to say everywhere was shut so no chance of BOSCH leads. However, the AA man tracked down a set of 'Electrospark OE quality leads' and fitted them. I must say, that the car is performing better with these than even brand new bosch leads.

PoloD.

the guy next door keeps bending valves giving a misfire on this type of engine.

first port of call is leads, cap, rotor, plugs etc....

then maybe if still there a comp test

I would buy a new set of leads. My car decided to burn a HT lead on 7pm christmas eve! Needless to say everywhere was shut so no chance of BOSCH leads. However, the AA man tracked down a set of 'Electrospark OE quality leads' and fitted them. I must say, that the car is performing better with these than even brand new bosch leads.

PoloD.

Guess I'll have to get a new set of leads then, thing is I need to use the car for a fairly long drive tomorrow and can't see me getting my hands on any leads unless I get em from the local vw stealers... which I don't particularly fancy doing.

I came across this when searching misfire on old posts:

" turns out the problem was to do with the leads.

i spoke to my uncle who works at a SEAT (obvo same stuff) main dealers and he said that a common problem involves the metal caps at the spark plug end of the ignition leads. undo the tabs on the metal bits and plug them back on.

done that, sorted. finally! "

^^^Not sure what he means really, has anyone heard/tried this b4?

Mine also did this after i cleaned TB and had it reset i changed sparks, leads cap and arm it runs like a dream now and i also had it on my 1.4 8v mk3 golf and changed those parts again and it solved that too.

Mine also did this after i cleaned TB and had it reset i changed sparks, leads cap and arm it runs like a dream now and i also had it on my 1.4 8v mk3 golf and changed those parts again and it solved that too.

Cheers 4 the reply m8.... did you change em all at once? it'd be nice to know if it would be solved by just changing one of those items.

Its possible the spark plug has become dirty from the tb cleaning. Try just cleaning the plugs,keeping them the same order before swapping them around

I changed plugs first which pretty much stopped it but the odd time it back back i did the leads and it solved it for good but i changed the dizzy and arm too as there only cheap.

these leads are the same on most vws, so your local motor factors will have a set no doubt.

Its possible the spark plug has become dirty from the tb cleaning. Try just cleaning the plugs,keeping them the same order before swapping them around

I had a look at the spark plug in cyclinder No1 and it seemed in pretty good condition. Nevertheless it's probably worth a go

I changed plugs first which pretty much stopped it but the odd time it back back i did the leads and it solved it for good but i changed the dizzy and arm too as there only cheap.

Yeah it's definitely probably a good idea to get them all changed... It just seems like i've been throwing loads of bits of cash at this car recently & they're all starting to add up!

I changed plugs first which pretty much stopped it but the odd time it back back i did the leads and it solved it for good but i changed the dizzy and arm too as there only cheap.

Yeah it's definitely probably a good idea to get them all changed... It just seems like i've been throwing loads of bits of cash at this car recently & they're all starting to add up!

Sounds like me i though i was buying a bargain car then i needed plugs £12 leads £25 dizzy £10 TB alignment £25 then cleaners and other bits you don't realize until you add it all up.. All part of motoring i guess lol.

Sounds like me i though i was buying a bargain car then i needed plugs £12 leads £25 dizzy £10 TB alignment £25 then cleaners and other bits you don't realize until you add it all up.. All part of motoring i guess lol.

Yep exactly the same here.... as soon as I've sorted one problem another seems to pop up! only little things really but they do all add up. At least the car was dirt cheap & I know once I've replaced them they shouldn't need doing for a fair while.

UPDATE

Just been on a 130 mile trip home (didn't want to with this misfire but in the end I just had to)

It wasn't a fun ride!! The misfire seems even worse than I had first thought. It seems to do it intermittently at a range of revs now, but always does it at idle or very low revs.

Also the power was apalling ... especially on long steady hills, I'd go into them in 5th at 70mph and the speed would just drop & drop even with my foot flat to the floor. I was getting overtaken by tranny vans pulling trailers!

Sometimes the power seemed OK but 90% of the time it was terrible.

Is it possible I have an airleak at the throttle body? The haynes manual says you should replace the throttle-to-manifold gasket after removing the throttle body, which I didn't do as it seemed fine, and I can't hear air whistling in or anything, but could this possibly be causing my misfire? or is it simply more likely to be plugs & leads?

Seriously, why don't you try just changing the leads? If you're unsure a mechanic may be the best bet.

PoloD.

Seriously, why don't you try just changing the leads? If you're unsure a mechanic may be the best bet.

PoloD.

Yeah I think I'll try plugs first then leads, just want to cover my bases m8, anyway guess my best bet will be to see if it's still isolated to cylinder no1 then I can swap the spark plug from cylinder 1 to say 2 and then I'll see whether the misfire follows the plug, if not it's most likely the lead.

When you buy a set of leads do you get a a king lead too?

Yea i did

Get em changed dude I'm positive it will cure it it sounds exactly like what i had change plugs first though as that might cure it as leads are £25 and that was using a halfords trade card sutton auto factors want £36 plugs where only £12