So i just got myself a evo 9 gsr and the problem is it randomly turns off like it would if i just turned off the ignition. I can start it up cold and it will run for about 10 seconds and just shut off and if im lucky it will start again after 15-30 seconds only to shut off again after another 10 seconds. Sometimes it can stay on for a while but if i drive for about 10 - 20 minutes (and it runs great) it just shuts off and it will only crank and eventually flood the sparkplugs. So to start it again after its flooded i have to either burn the plugs clean from gasoline or let it sit overnight. It has a bouncy reading from the o2 sensor so i think it is bad? I ordered a new one but this cant be the problem with it shutting off? (at idle it runs at a shaky 1500rpm with tiny pops and it suddenly will go a little up in rpm before it goes down to about 1500 again) Its got new injectors, fuel pump, coils, crank sensor (oem), decat and larger downpipe.

Its checked for vacum/boost leaks.

I have ordered new spark plugs, new cam sensors and new o2 sensor.

The car has oem ecu, oem turbo and untouched engine as far at i know. The ecu might have been flashed at some point. Do I have to "tune" in the decat if this hasnt been done?

 

Anyone?

 

Its really hard to say, there isn't a ton of info on "how" it turns off.

Does the idle bounce or does it just die?
What is your wideband; if you have one, doing when this is happening?
What else have you troubleshot other than the vacuum and boost leak test?
Does it always crank?

To me, this sounds like a possible sensor issue; maybe cam or crank sensor? Its super hard to say for sure though. My suggestion would be trying to get a log of it shutting off and/or not starting. The thing that is throwing me is the flooding part? If it was a crank sensor, it wouldn't flood?

 

It just dies like turning off the ignition at random times and no bouncing. and usually if it runs longer than a minute or so it will not die on idle at least
I just changed the o2 sensor right after the turbo and it runs cleaner on idle but still just shuts off like before.
I have changed crank sensor, both cam sensors and o2 sensor without any luck.
Yes it always cranks.

 

Ok, so I think the next step is to log the sensors as the cranking but not starting is happening. To me, this still sounds like a sensor issue.

It could in theory be the coils overheating, do you have a buddy you could swap coils with to test?

 

No, but I still have the original coils. The coils on the car are upgraded by previous owner and checked for spark and work.

 

Yea, testing the coils is one step, but if they are overheating and failing it might be hard to pickup on a tester.

I'd try to get a log of it not starting while logging the cam, crank and MAP sensors. To me, I really think thats whats happening but its super hard to say.

 

just to be clear, engine dying will still keep all the lights/ignition on, unless you literally mean everything is turned off (ACC)

 

Ooo thats a good questionnn. I just assumed ACC stayed on and the engine turned off but that would be a whole different ball of worms if the ACC turn off.

 

What is acc? Its only the engine that turns off. Not the ignition or anything else

 

Like accessories like lights, radio, etc.

So just the engine points back to my last post. You'll have to do some logging and troubleshooting to get some more data before a cause can be determined.

 

Ok, ill get someone with a good obd reader to help. Then get back with what we found.

 

Double check the grounds, especially the one for the manifold. Grounding issues are normally uneventful. Oil getting into cam sensors connectors might also

 

Ok, i will! I really appreciate the help from you guys. Thank you.