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Hope some one can help with the following, all ideas and thoughts welcome!

Last week my car (95, UK, 1.8 MK1) developed an awful intermittent misfire which caused the car to shudder and jerk at speed. Other symptoms were the rev counter bouncing round like a loon. I thought this would be cured by changing the HT leads and plugs which I did on Sunday The car then ran perfectly up until a few days later (today) the same misfire occurred briefly on the way to work but has since ceased.

Obviously I have not cured the problem and the only other suggestion I can point to is the coilpack or maybe the ecu. Has anyone had similar issues?

I hate to throw parts at a problem without the proper diagnosis but if I could get hold of a known working coilpack and ECU from a breaker I'd be happy to give it a go. My second question would be, are the ECU and coilpack the same across all years of the mk1 1.8, both UK and import?

Thanks in advance!

Lee
 

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Discussion Starter · #3 ·
Cheers mate. Have identified that I have a three pin version and have a unit due to arrive by the end of the week. I'm hopeful this will sort the problem out! I'll post my findings just in case this proves useful to someone else in the future.
 

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Rollin' on 15's, baby!
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AFAIK, coil failure on the 1.8 engine is a common problem. Sounds like you are on the right track.
 

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Discussion Starter · #5 ·
Almost at my wits end over this one! Have changed ifs, leads, coil pack and cam angle sensor plus cleaned all the earths I could find and the bloody misfire still persists.

When I run the engine I am fairly sure I can hear the ticking noise that arcing would make but can see no evidence to back this up. I really can fathom out why the issue is so intermittent, sometimes the car feels perfect but the all of a sudden it goes batshit crazy in me. Any thoughts guys? All suggestions will be very much appeciated!!
 

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Rollin' on 15's, baby!
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Have you checked the ECU for fault codes?
 

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Discussion Starter · #7 ·
Afraid not, I'm going to try and get hold of a reader or failing that try and make my own DIY jobbie as seen on the net.

But after today I would much rather spend money on a jerry can full of fuel and a box of matches!
 

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Discussion Starter · #8 ·
Right, I have made my very own code reader which is very cool by the way!

It's turned out the following codes:

10 Intake air thermistor in airflow meter

14 twice or 28?? Atmospheric pressure sensor or 28 EGR solenoid valve (vent)(1.8L)

13 No code given
 

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Almost at my wits end over this one! Have changed ifs, leads, coil pack and cam angle sensor plus cleaned all the earths I could find and the bloody misfire still persists.

When I run the engine I am fairly sure I can hear the ticking noise that arcing would make but can see no evidence to back this up. I really can fathom out why the issue is so intermittent, sometimes the car feels perfect but the all of a sudden it goes batshit crazy in me. Any thoughts guys? All suggestions will be very much appeciated!!
How fun is it to start?

Check your plugs. Clean them, run it till you get the misfire. Pull em one at a time, check for a wet plug, or a standout residue... One black, the rest brown, etc...

Burning oil on misfire?

If they're all wet, or black soot covered, money is on cambelt, or cam slipping a tooth.

Hearing the arcing... Could also be predet.

Spray alcohol vapor around the intake manifold while running, listen for engine note change. If it changes, vacuum leak.

How long does it take to misfire when you drive it?
 

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Discussion Starter · #10 ·
Cheers Calmdown! Well, the car starts 1st time every time without issue at all and idles perfectly at the same time.

All of the plugs are perfectly clean and not in any way contaminated, there is however a faint burnt oil smell when I stop the car after its had one of its misfiring fits?

The most annoying thing about the misfire is it being intermittent but mostly it occurs when the car is up to temp and under load. I simply cannot get the car to do this when it's stood-it all happens when on the move!

Going to check the ECU and MAF sensor next as that is what the fault codes are hinting towards....
 
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