2015 Subaru Impreza Sedan WRX - Need ideas

Rebulit Engine due to spund rod bearing.But everything back togetther as per manual. Car has spark, fuel, air and compression. Cranks over but will not start. Have done the timing as per repair manual 3 times. Checked all grounds, replaced crank and cam sensors. Out of ideas.

Are you sure the bottom and top are in synch? That usually means cylinder 1 is at TDC on its compression stroke (not exhaust stroke) and the valves for cylinder 1 are all closed.

It could be the PCM. The PCM would cause the engine not to start. As the PCM sends the signal to the positioning the crankshaft and controlling the ignition spark and timing.

Verify spark and fuel

I would assume the top an bottom are in sync because I’ve timed it 3 different times. Timing is syncing in the top and bottom correct?

I was under the impression that if the OCM was in issue and not receiving or sending to the crank position sensor then the coils wouldnt be getting spark. Or am I way off?

I have verified spark( ignition coils as well as the plugs. Pump is coming on and all plugs have a fuel smell on them.

Yes. A key step is to make sure cylinder 1 is at TDC on its compression stroke.

I was under the the impression that you could have spark if it was the PCM/ECM

In some cases, a PCM problem will cause the vehicle not to run at all. The PCM’s functions include positioning the crankshaft and controlling the ignition spark and timing. If there are problems with how the PCM performs these functions, the vehicle will not run.

ECM is the computer that takes data from the cooling system, exhaust, intake, and a few other components. It has control over the ignition timing, fuel injection timing, and the position of the camshafts and throttle.

So I am stilling leaning towards a computer problem. You could check with a OBDII and see if there is any codes if you have the scanner. You could also try resting the ECM by disconnecting the battery let it set for 15-30 minutes. Then once it starts it would have to relearn everything and if it does start you should let it run for at least 10 minutes so it can relearn everything.

Last thing computers will go if there happens to be a voltage spike. When reassembling the wire there could had been a spike.

How have you verified compression? With compression, spark, and fuel pressure present it should run IF everything is timing correctly and IF the fuel injectors are pulsing. You might listen to the injectors and note if you hear them clicking.

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I do have decent compression in all cylinders. They’re a little off but I’m assuming that’s because the rings haven’t seated yet. I’m not sure how the timing could possibly be off at this point. I have fuel in all cylinders Bc the plugs get wet when I try an fire it up.

So what does “decent compression” mean in numbers? Verified or guessed at?

Wet plugs could mean the injectors are staying open, the plugs are not firing, or the compression/timing is not correct.
For what it’s worth, rings seating won’t make that much difference in whether or not an engine starts. If it won’t start because of rings seating then there is a serious problem in there.

Well the compression is all around 190 -210. I mean that if the rings haven’t fully seated and the engine is cold then the compression may be off a little from where it has to be, well from my understanding and research. The plugs yes are wet but they have the dark tips as if they were getting spark. I followed the timing manual to a t but I mean something could have been just wrong. Thank you for your response but I have you on it an decided to take it to the Subaru dealer today. They think it’s the timing as well or it’s one if the things they have to verify to trouble shoot. I honestly think it’s an electrical issue but they have their procedures to follow.

The compression is great at 190-210. No issue there at all. I would think that if the cam timing were off the compression would not be that high.

At this point I wonder if the injectors are not pulsing as they should so I tend to think there may be an electrical issue; maybe related to the crank sensor or PCM.
I’ve only run into one car over the years with injectors being held open all the time and that was on a Volvo with a bad ECU. In that particular case the problem was caused by the owner; a traveling salesman who chose to throw all of his debris into the passenger front floor. Eventually a not quite empty can of Donald Duck orange juice rolled underneath the seat and the remaining juice oozed onto and past the ECU connector.

The acid in the orange juice ate up a pinkie fingernail aized area of printed circuit board and that caused the injectors to stay open. Needless to say, when I figured it out and called him with the news he would not believe me. He believed when he saw. Just when you think things can’t get any odder…

Let us know what the dealer said. I am curious and what to see if my train of thought was right.

Yeh will do. Subaru being Subaru said they’re going to follow their procedures an pull the engine and verify timing first. Good ol $900 just for that. But I will keep you guys in the loop.

I admittedly have an issue with a 900 dollar fishing expedition which brings up a few questions in my mind.

  1. What if they find nothing wrong with the timing?
  2. How confident are you that they will admit to it?
  3. What if they determine once engine is out the problem is not timing at all but a simple wire connection problem and tell you the timing was off anyway?

It would seem to me that using a cheap Noid Light (or stethoscope or even an ear against a screwdriver handle) would be a far easier injector pulse check than yanking the engine out. I tend to think that with compression that good the timing is likely correct.
I wish you the best on this issue.

So they called an they have already got it running. They didn’t say what exactly it was but I’ll get the write up tomorrow an let you guys know.


I am very curious as to how this worked out. I’ve worked for 3 Subaru dealers over the years and can say that there is no way I (or 98% of the mechanics I worked with) would go on a 900 dollar fishing trip without verifying other things first. The 2% I worked with probably would but they were never around for very long as crooks or vastly incompetent techs (word used loosely) don’t have much longevity.

Hopefully they discovered something simple and saved you some money.

You need to stop and address what has been mentioned several times.

VERIFY that the engine is mechanically timed correctly…this means removing the timing belt covers etc… The belt must be on its cogs PERFECTLY…not close to…but absolutely perfect… Things can get away from you when you release the auto tensioner and tension the belt for the first time…you are supposed to verify at that moment again that you didnt get a tooth off or are 180 out of synch. Trust me…it happens…a lot. You must check.

Verify that when you look at your timing marks and she is at TDC…that the number one…is on its comp stroke…as @shanonia mentioned early on…this is the only way it can be.

These checks I and others mention are a Stop and check before you do anything proposition…no assumptions can be made here…none. Verify…its beyond important.

At the moment you cannot give us concrete answers on the state of your mechanical timing…get to that point and report back.