2020/07/21 20:42:06
1993MR2GIRL
Please help we are trying everything and could use some tips

My mr2 has been starting up fine but as soon as it gets warm is starts to misfire and die and I can’t start it till it’s completely cold.
We have replaced the ignition coil to a brand new one, we are going to change the ignitor.
But we getting pretty stuck if it isn’t the ignitor.
Any help please 😩


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2020/07/21 21:18:03
MG_MR2
What voltage you showing off the battery as it’s running then as it starts to die?
2020/07/21 21:19:35
twomr2`s
if its not throwing any fault codes id compression test it first,
if its got good compression then id look at the ecu capacitors as its easy enough to do.
could also check out the dizzy-if theres a bunch of oil under the cap it may have a crack and oils getting in (seen this twice in the past few months)
 
 
2020/07/21 21:51:04
1993MR2GIRL
MG_MR2

What voltage you showing off the battery as it’s running then as it starts to die?





It is at normal volt the whole time even when dying.
2020/07/21 21:52:30
1993MR2GIRL
twomr2`s
if its not throwing any fault codes id compression test it first,
if its got good compression then id look at the ecu capacitors as its easy enough to do.
could also check out the dizzy-if theres a bunch of oil under the cap it may have a crack and oils getting in (seen this twice in the past few months)
 
 


 
i don't have a factory ecu, i have a aftermarket one (motec m4) 
will be replacing dizzy as i have a spare one
 
will speak to my partner and get back to you. 
2020/07/22 11:20:06
Falcon
Just for diagnosing purposes it's worth using a spark plug earthed to the top of inlet manifold with an extended high tension lead direct from the coil. This can allow you to check the quality of the spark when it's playing up as opposed to when it's starting correctly from cold. 
I recently had a whole lot of learning experience with the EFI relay located in engine bay fuse box.
The little b#$**# that will burn your finger any time you go near it.
Very easy to put a new one in to find out. Available at any auto sparky supplier for about $35.
I had very similar cold-hot symptoms. Bit more intermittent than yours.
Only took me a fortnight to isolate that little blighter.
Please let us know how you get on.
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