Mi16 Misfire When Warm

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I am running a std Mi16 with the BX ecu and loom. It started missing on Sunday and has quickly become worse over the week.

 

I had this problem about a month ago then I removed the dizzy cap cleaned it and it has run up until Sunday. I have now replaced the cap and rota arm for new and swapped the ing amp for another and fitted with heat sink paste.

 

I think it is electrical as when the car is driving and missing you can cost in gear down a hill so the engine revs stay at 3K but the rev counter is jumping all over the place.

 

Would this point to the coil?

 

I have also run the car with the ecu temp sender unplugged, it runs (just) but the misfire is still the same.

 

The only other thing I can think of is the C.A.S. but I would have thought that would work or not work.

 

All help welcome.

 

I have has a quick search but as I am in work can't spend too long at it.

 

Many Thanks.

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[KRISKARRERA 2 1 Cars]

swapped the ing amp for another and fitted with heat sink paste.

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What make is the new ignition amp?

[welshpug 1,657]

sounds likely to amp or the coil related if the rev counter is doing a merry dance as it is dependent on a signal from the coil, it could be amp or coil failure especially if it worsens when they get warmer, or it could be power supply to either, possibly a dodgy relay or connection.

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The ing amp is not new but was working when I removed it, both are bosch.

[Miles 331 1 Cars]

Blue bosch one's are fine, the black ones are hit and miss.

Worth checking the Earth's are OK along with the connectors in the plug's as the wire's now are all corroding and causing a higher than normal resistance

Edited May 26, 2010 by Miles

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I have also had a good prod and poke at the plugs in the loom and every thing looks ok.

Before I pull the loom out has anyone got some more ideas?

 

It looks as if something is breaking down (apart from the car) as it will drive for 10 min with no problems. But when what ever is giving me the problem gets warm the car starts missing.

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Update, I took the car for a drive until it faulted then fitted a new coil the problem was still the same.

 

That was a couple of days ago, got around to having a look again tonight. Again I ran the ar until it started to miss. Tested the voltage to the coil all looked ok, gave all the plugs and loom a good pull about and nothing.

 

At this point i refitted the coil (c1) I had removed last week as it was cold and worked in this state, the car ran ok.

 

Refitted the new coil (c2) and the car started to miss.

 

fitted c1 car ran ok

 

fitted c2 car missing

 

fitted c1 car ran ok

 

fitted c2 car missing

 

you get the idea. I did this about 8 times every time i fitted coil c1 the car would run and with c2 it would misfire.

 

This to me is now looking like I have 2 duff (mmmmm duff) coils. The new one is a"new" Intermotor one any coments on them?

 

The only thing that has got me thinking is why did the new coil (c2) start missing the first time i fitted it and now acts like the old one ie breaking down when hot.