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Injector cutting out engine misfire when injector cuts out

Maurice Business Development Manager Australia Posted   Latest  
Discussion
Driveability

I am looking at this for my friend Darryl Blacker who is from a Country Town in Australia. This is a Mitsubishi Triton 4 cyl Petrol (Gasoline) and has driveability issues. Have a look at the captures and what do you all make of this? We have injector current in the red which goes form about .5 amp to nearly 1 amp. The current ramp pattern and shape continues to change as you see. There are times were the current spikes and cause multiple injector fires.

I sent this capture to another Tech friend Rod this morning and he asked me where the amp clamp is placed, it is clamped straight to the wire at the ECM. Rod was eluding that if it was on a fuse we could be getting feedback. I did asked Darryl (the Tech working on this vehicle) to use another AMP clamp as I have been caught with faulty clamps of batteries going flat. So the problem is the same with different clamps.

I have asked Darryl to try disconnecting the Alternator and go from a second road test to see if we may be getting AC ripple cause these issues.

Any ideas guys?

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Walter Technician
Florida
Walter
   

I'd be looking at fuel\fuel trim. You've got injectors firing on top of an injector firing event already in progress. It's trying to make up for a lean condition. As for the injector cutting out I'd look closer and probe it the injector may be failing due to the increased activity and or the injector driver may be failing. Measure your injector on time and do the math. It will also explain the

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Richard Diagnostician
Virginia
Richard
   

I don’t have a wiring diagram or SI for this vehicle . I think you should move the amp clamp to the control wire for the injector then don’t touch anything. Test drive until it acts again and look at the scope.

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Richard Diagnostician
Virginia
Richard
   

If the current ramp is normal and the spikes still appear then I think the control wire is touching ground somewhere. Make sure the clamp is at the ECM .

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Eric Owner/Technician
Wisconsin
Eric
 

I'm sure the lack of responses is partly due to this vehicle being unavailable in the USA and the lack of testing information provided. Since we don't have access to a wiring diagram it is difficult for us to tell what could be causing the abnormal scope patterns. I have some questions to help me understand this system better. Please correct me where I am wrong. Where is the amp clamp

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