Classic Audi Technical Mech/Tech Engine » 87 1.8gt Coupe Misfire

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Old 15-02-18, 10:48 AM   #1
5potJacko
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Default 87 1.8gt Coupe Misfire

I've recently acquired an 87 coupe gt with the 1.8 4 cylinder engine. It has a constant misfire and the previous owner told me this is on cylinder 4. Does anyone have any experience on these engine and if so anything obvious I should be looking for?

Its had a brand new dis cap, rotor arm, plugs and leads and it didnt fix it (again previous owner)
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Old 15-02-18, 11:09 AM   #2
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First thing I would do is to crosscheck the initial diagnosis and disconnect No.4 plug lead and see whether the misfire is changed in any way, if not then at least you have confirmed where to focus your attentions.
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Old 15-02-18, 12:33 PM   #3
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A compression check would be a good way to proceed

Last edited by steveb; 15-02-18 at 12:36 PM.
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Old 15-02-18, 03:23 PM   #4
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Honestly, I would discard anything the previous owner has hinted at such as new plugs, leads, dizzy cap etc.....

A compression check and leakdown check is a good way to start, if you get acceptable readings then go on to doing as vagdream suggests. I would be certainly looking at condition of plugs....get yourself a set of inline spark indicators, that way you'll be able to see if you have good spark on all four pots.

Of course, could be a fuelling issue - bad injector/seals - do a test to determine flow rates and spray pattern.

Steady and methodical...don't take anything for granted!!
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Old 19-02-18, 01:40 PM   #5
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Solved this within 10minutes of investigation. Although the spark plugs were reletivley new, one wasnt working properly so 250 later and its running spot on! Cheers for all help
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Old 19-02-18, 04:24 PM   #6
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250 for a spark plug?
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Old 19-02-18, 04:40 PM   #7
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2.50 maybe for a W6DTC?
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Old 20-02-18, 12:16 PM   #8
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Halfords prices!
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