2013 Mazda 3 sky active

Jamie Owner/Technician Ontario Posted   Latest   Edited  
Resolved
Driveability
2013 Mazda 3 GS-SKY 2.0L (8) 6-spd (C66M-R)
Crank / No Start

Vin - JM1BL74D1828616

Vehicle has come to me from another shop. The coils fire consistently, however, the injectors only fire intermittently. Tested powers and grounds,- all good. Cam and crank sensors look normal, however, I can't seem to find a cam/crank correlation waveform. The maf voltage is in spec and does change when cranking if the maf is disconnected. The engine will start, but runs poorly and will stall after 2 seconds or so. The pcm does fire the injectors regularly with the maf disconnected. 5v reference and ground are good at the Maf. I tried a new maf and no change. We installed a used pcm with no change. The previous pcm didn't recognize when the maf was disconnected, the new pcm does recognize when the maf is disconnected. Fuel pressure is within spec on both the low and high side (according to the scantool).

Any thoughts?

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Alex Diagnostician
Australia
Alex
 

No Codes? Is the PCM shutting down the injectors because of another input anomaly? ECT?

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Jamie Owner/Technician
Ontario
Jamie
   

No codes in any modules. The pcm does fire the injectors intermittently, but not enough to get it to start. Ect and ambient Temps are correct. The cam sensors have output and the scantool shows rpm, so it has crank sensor output. Maf disconnected it does run but poorly. Im going to do an in cylinder compression capture in the morning

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Richard Technician
New York
Richard
 

Did the other shop say what they had done to the vehicle? Did they remove the crank pulley for any reason? I believe this is one of the engines that you have to use the special holding tools when the crank pulley is removed or the timing could slip if the engine is turned without the crank pulley on and tight.

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Agree
Jamie Owner/Technician
Ontario
Jamie
 

They actually never got beyond checking fuel and spark. The engine hasn't been disassembled that I can see. It was towed to them as a no start

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Stephen Owner/Technician
California
Stephen
 

Scope the crankshaft sensor, see that the bottom square wave pulls all the way down to zero volts. If not, you may have a sensor problem or the air gap isn't correct

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Alex Diagnostician
Australia
Alex
 

This is the Skyactiv engine right? Finicky. Agree valve timing could be an issue here. Not taken off one of these pulleys, but I think this is keyed … Possible chain wear or tensioner issue. I don't have a cam/crank correlation, sorry.

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Ray Diagnostician
Ontario
Ray
 

2014 Mazda3 2.0 cmp ckp with measurements. HTH

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Thanks
Jamie Owner/Technician
Ontario
Jamie
 

Thank you very much. Ill do that tomorrow morning

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Jamie Owner/Technician
Ontario
Jamie
   

Reach out and thanks to Ray. Cam and crank correlation was off due to what I am assuming is a worn/stretched timing chain. Due to the number of KM’s and overall condition of the vehicle the client does not want to proceed any further and will be dealing the car. Thanks again for the input. i wish I could figure out how to change the status to resolved !!

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Thanks
Anis Technical Support Specialist
Romania
Anis
 

They usually have a problem with the low side fuel pump. Can you provide the full VIN? Here is some info: Fuel pressure 405—485 kPa {4.13—4.94 kgf/cm 2, 58.8—70.3 psi} Fuel hold pressure 230 kPa {2.35 kgf/cm 2, 33.4 psi} or more

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Jamie Owner/Technician
Ontario
Jamie Resolution
 

Figured it out

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