Very strange misfire issue.
#1
Very strange misfire issue.
Hello everyone,
I've got a strange misfire that I can not figure out, and I thought it would see if anyone has some ideas.
It is a 98 Mini with the MPI fuel injection.
The car has dead miss on cylinders 3 & 4.
Here is what I know:
I first replaced the plugs and wires because they were blasted out anyhow
Then I checked to verify that I had spark - I do on all 4
Then I checked my fuel injectors for power and ground - Noid light flashes the same for both injectors. So, I then switched the injectors to see if the misfire would follow, and it doesn't.
After that I did a compression and leakdown test, both passed perfectly.
So still baffled, I then removed the coolant temperature sensor and tested it - passes fine. Check IAT sensor - passes test. Checked TPS sensor - passes test.
What I found out then is that cylinders 3 & 4 are being heavily washed out with fuel. Both pistons are very much cleaner than 1 & 2, and when I unplug cylinder 3&4 injector the idle smooths out instantly, just for a few seconds until all the fuel is burnt up and then it resumes its misfire.
Any thoughts would be greatly appreciated. Thanks!
I've got a strange misfire that I can not figure out, and I thought it would see if anyone has some ideas.
It is a 98 Mini with the MPI fuel injection.
The car has dead miss on cylinders 3 & 4.
Here is what I know:
I first replaced the plugs and wires because they were blasted out anyhow
Then I checked to verify that I had spark - I do on all 4
Then I checked my fuel injectors for power and ground - Noid light flashes the same for both injectors. So, I then switched the injectors to see if the misfire would follow, and it doesn't.
After that I did a compression and leakdown test, both passed perfectly.
So still baffled, I then removed the coolant temperature sensor and tested it - passes fine. Check IAT sensor - passes test. Checked TPS sensor - passes test.
What I found out then is that cylinders 3 & 4 are being heavily washed out with fuel. Both pistons are very much cleaner than 1 & 2, and when I unplug cylinder 3&4 injector the idle smooths out instantly, just for a few seconds until all the fuel is burnt up and then it resumes its misfire.
Any thoughts would be greatly appreciated. Thanks!
#2
#3
#5
OP does not mention where he is
but it is my understanding the scarcity of ECU diagnostic tools for the SPI/MPI systems on Mini in the U.S. is a strong reason for avoiding them
often this is about the time owners begin to consider changing over to a carb set up ....
there are kits available
as well as replacement ECUs
but it is my understanding the scarcity of ECU diagnostic tools for the SPI/MPI systems on Mini in the U.S. is a strong reason for avoiding them
often this is about the time owners begin to consider changing over to a carb set up ....
there are kits available
as well as replacement ECUs
#6
Changing an MPi to carb is a big job, no distributor so you have to change the ECU to an aftermarket.
I'm pretty sure a couple of the US Mini specialists have the reader and some electronic parts are available even here in the US, but depending on the OP's location it could be a challenge getting it checked out and fixed.
I'm pretty sure a couple of the US Mini specialists have the reader and some electronic parts are available even here in the US, but depending on the OP's location it could be a challenge getting it checked out and fixed.
#7
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#8
Changing an MPi to carb is a big job, no distributor so you have to change the ECU to an aftermarket.
I'm pretty sure a couple of the US Mini specialists have the reader and some electronic parts are available even here in the US, but depending on the OP's location it could be a challenge getting it checked out and fixed.
I'm pretty sure a couple of the US Mini specialists have the reader and some electronic parts are available even here in the US, but depending on the OP's location it could be a challenge getting it checked out and fixed.
#10
Sorry for the delay in response. Still no new findings over here. Id love a scanner that could communicate with this thing. I've got a Launch system that has Rover as an option, but I don't know how to get into it - the model options for it don't seem to jive. Strangely enough is has no check engine light on......
Thanks for the help guys! Anything else is appreciated
I will continue to post if there are any other updates/findings.
Thanks for the help guys! Anything else is appreciated
I will continue to post if there are any other updates/findings.
#13
Sorry for the delay in response. Still no new findings over here. Id love a scanner that could communicate with this thing. I've got a Launch system that has Rover as an option, but I don't know how to get into it - the model options for it don't seem to jive. Strangely enough is has no check engine light on......
Thanks for the help guys! Anything else is appreciated
I will continue to post if there are any other updates/findings.
Thanks for the help guys! Anything else is appreciated
I will continue to post if there are any other updates/findings.