Volkswagen Polo III (1994 - 1999) - 97 1.4 8v Mis-fire.

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Fri 11 Jan 2008 20:23
97 1.4 8v Mis-fire. - island
Very similar to Akialmera problem of 8 weeks ago. Car had been running fine before a xmas break but on return after approx 3 miles started mis-fire. Changed plugs ,ht-leads dis cap and rotor. Also notice that front pipe with cat had small hole so that has also been replaced along with cat. Car starts fine but idles between 800-1200 rpm. feels very much like car running on three cylinders then back to four. very laboured up hills. None of the changes stopped the misfire(fuel consumption increased big time).
Booked car into garage no faults come up on diagnostics comp but they changed a temp switch near distributor, after recording high fuel readings (no change). They are now advising new epu? . Any info would be gratefully received.

Edited by Pugugly {P} on 11/01/2008 at 20:24

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Fri 11 Jan 2008 20:31
97 1.4 8v Mis-fire. - Screwloose
island

What was this temp switch they changed? Was it the four-pin temp sensor in the plastic top-hose housing? Your symptoms would certainly suggest a fault with that unit.

Were the temp readings coming from it incorrect? Are they now in range on the live-data reading?

Edited by Screwloose on 11/01/2008 at 20:32

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Fri 11 Jan 2008 23:31
97 1.4 8v Mis-fire. - island
Yes the sensor that was changed was indeed the one at the top.As for the readings i will have to get back to you on that .I will ask them on Monday.
Thanks very much for your help.
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Tue 29 Jan 2008 20:38
97 1.4 8v Mis-fire. - joshjones
Hi you two. And thanks for broadcasting your expieriences. No prizes for guessing that I'm experiencing exactly the same misfire symptoms. I've done the obvious bits (new dizzy cap, rotor arm and plugs) and the leads are as good as new but under 2,000rpm my Polo (P Reg) is still acting as though we are on three cylinders. Funny thing is, I can't identify a particular cylinder that is constantly misfiring and I am, in technical terms, flummoxed. Did either of you get to the bottom of the trouble? One thought I have had is that the petrol I put in may have been sub standard but a new tank of expensive stuff still does't seem to have helped. My next steps are to try a new coil, leads, and to investigate fuel supply issues (I've cleaned the carb) but if you two know of a specific issue, I'd be really grateful to hear.

Many thanks
snipquote

Edited by Dynamic Dave on 29/01/2008 at 20:50

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Tue 29 Jan 2008 21:27
97 1.4 8v Mis-fire. - Screwloose
josh

Is it on 3-cyls at idle or just under load? How old are the HT leads?

Do you have an engine code. Have you a basic voltmeter?
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Wed 30 Jan 2008 03:42
97 1.4 8v Mis-fire. - joshjones
Hi. It seems to idle quite unevenly and the minute it's under load, it's struggling. Yes to the voltmeter question, no to the engine code -but tell me where to look and I'll find it for you. I know you are going to tell me to replace the leads, and I know I should, I was just hoping your advice might save me the cost. My thinking was that, given that the replacements I've already done made no difference, the problem may be fuel rather than sparks.

JJ
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Wed 30 Jan 2008 12:34
97 1.4 8v Mis-fire. - Screwloose
JJ

A duff lead would kill one cylinder; just pull them off one at a time when it's idling and the one that's duff doesn't make a difference.

If you've got a voltmeter; connect it into the black wire circuit coming from the oxygen sensor [use a pin into the back of the plug] and watch what's happening at idle warmed-up. It should be sweeping 0.1 to 0.8 volts.
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Fri 1 Feb 2008 13:38
97 1.4 8v Mis-fire. - joshjones
Hi Screwloose.

Thanks for all your help. I still can't work it out, so it's off to the experts I'm afraid. I'll keep you posted.

JJ
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Thu 19 Nov 2009 22:00
97 1.4 8v Mis-fire. - bigberth
hi there i have a 97 1ltr polo doing the same thing i was wondering did you get your problem sorted
SQ

Edited by Dynamic Dave on 20/11/2009 at 00:43

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Thu 19 Nov 2009 22:13
97 1.4 8v Mis-fire. - bell boy
as said earlier these cars eat dizzy caps/rotor arms and leads
these need checking before garage give heap big bill
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Mon 16 May 2011 05:15
97 1.4 8v Mis-fire. - my_shit_polo

hi, im having the exact same problem with my 1.4 8v 1996 polo...

ive done the leads, dizzy cap,and arm. It runs slightly better, but it still feels like its misfiring and uses LOOOAAAAAADS of petrol..

at idol it feels like its about to cut out and at low revs when driving.. pls anyone that could shed some light do so!!!

also when i unplug cylinder 4 from the dizzy cap it makes no difference, so i know that that is the dead bit. but it still sparks..

so the plug and lead are both fine, the distributor cap is brand new as well as the rotor arm so i dont know what could be going wrong... could it be a fuel injector? the cylinder pressure has been checked and its normal if thats any help?

please help me??

Edited by my_shit_polo on 16/05/2011 at 05:27

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