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Subaru Starting Issues - Please Help

I’ll make this as abridged as possible. Basically:

Three weeks ago my 2001 Subaru Legacy Outback was intermittent no start. It cranked weakly, with rumbles and shudders before it died unless I teased the gas pedal just as it tried to turn over. Sounded like a fuel issue.
We looked for issues and attached a missing ground strap. We also cleaned around the grounds and reset the timing. It started and ran beautifully.

But then I got it home and the next morning it ran okay. Still rough start. But at least it was starting and running for a few weeks. It started blowing coolant so we pulled motor for HG job. Had no spark after re-install.

If we put the test light + to the coil power and test light - to the Bank 1 trigger, the LED lights up til you start cranking, then shuts off for the duration of the cranking and then times for 1.5 sec’s after the Crank, and lights back up steady. (It coincides with the CEL being lit on the cluster). If we probe the - to the Bank 2 trigger, it’s just lit continuously whether cranking or not.

We resistance tested both Crank and Cam sensors and they are w/in spec. We pinned out the wires thru the harness to the ECU, and they test out.

The dang thing then signalled the coil so we plugged it in and it ran for 15 sec’s including idling and revs… So we installed accessories and then it once again had no spark. We blamed the ignition switch…it WAS notchy, but we cleaned it up inside and it now tests reliable during ‘on’ and ‘crank’ cycles.

We swapped the ECU and nothing was solved. It just cranks. I’m at a loss. Scanner isn’t throwing any codes. What’s going on?

Sounds like a terrible hit and miss mess. You might try testing the crank sensor for output voltage on AC scale of volt meter while cranking. May not be the problem but would eliminate one possibility.

Hmmm… Sounds to me as though you should just replace that ignition switch if it was suspect in any way. Also…why did it turn over “weakly” that points to insufficient voltage and amps from battery…you need a healthy battery to crank the engine while providing proper voltage to the ecu, this is rather important.

Re-install the factory ECU… it should not have been changed at the stage you were at and shouldn’t have been swapped out… Yet.

Any questions or investigations into your engine timing should have led you directly to the timing belt…if you somehow jumped a tooth on either cam you would see issues identical to what you have described here except for the “weak” cranking (battery). Just check the timing belt accuracy…be absolutely certain that you are dead on with the timing marks, no deviation is acceptable here in any way…so its important to put it mildly.

Do you have any spark? Have you checked? If you DO have spark what is its quality of it? Is the spark strong and Blue or weak and Orange? If it is Orange you have a bad ignition Ignitor… The ignitor throws many people off because they see spark and think they are good to go and look no further…however all sparks are not created equal. Your problem description made me think about the Ignitor once I got past the weak cranking issue (which must be solved). If you have no spark at all then your crank sensor and coil will be suspect but since you had it running a little bit it suggests they are functioning somewhat. Test them anyway.

I would be highly suspicious of the Ignitor at this point in time… This assumes your Battery, ignition coils, cranks sensor, Ignition timing and engine compression are good. If all those items check out, it is then up to the ignitor to get your spark to proper strength. Look through the items listed as none of them are unimportant. I am very suspicious of your ignitor. I’d get another ignitor and see what you get.

I focused on the ignition system here because of your problem description…However… What happens when you shoot it with starting fluid? Does it start and run no problem? This is suggestive of fueling problems… so do that test of course.

Just some of the things I would go through… One of them is going to be the solution… Go through the items and check them off the list.

We’ve tested both crank and cam sensors. They’re both new as of a few months ago too… Thanks for replying.

It has no spark at all once we start cranking. We have rechecked the timing and it all seems fine… I’ll check it again just to be 100% sure on that. And it was only “turning over” weakly that one time. Now it cranks without any hesitation or rumbling as was per usual… it just can’t start. Spark plugs are all new, too. What I did notice was that when it did briefly start, the alternator was unhooked but still plugged in electronically. We had disconnected the ECU and then reinstalled it. I’m convinced we should repeat what we did and see if it starts again. But it IS a spark issue.
Thanks for replying.

You have to be CERTAIN that you are getting power to the coils and ecu while the ignition is in the crank position. It is not uncommon to have an ignition switch fail in this manner… Power in the ON position…then it loses power while cranking…then power returns when key springs back to the ON/Run position.

The first time I encountered this wasn’t pretty…but eventually it was sniffed out. It is possible and its cheap insurance just for your sanity, to be honest. If you want…just bridge power to the ignition wire so you know its got steady uninterrupted power…then crank away. Take the responsibility for ignition power away from the ignition switch for a temp test… Not hard to do real quick.

How did you test the sensors…do you have a sensor tester? Ohm-ing them out is not a valid test. But I suppose if they are all now new the problem is not likely there tho…not impossible honestly… A diagnostic computer is invaluable in these instances…and if you like old school… The old Actron CP9087 is still a trusty dusty companion I still use to this day.

Not a common failure, and I don’t remember what vehicle I was working on, but I didn’t have spark during crank, metered the lack of signal from the ECU. I unplugged Ecu. Connector looked clean . Plugged it back in and truck started right up. Cleaned the connector and had no problems since.

Worked on it yesterday and switched out the camshaft position sensor for a new one (again). The wiring had been taped from when I previously installed the last CPS so I soldered them back together. It tested good. The car started. Turned it off and started it again just to be sure. It started right up so we started reattaching accessories. I went to start it again and it just cranked… Tried again, and spark is gone. We tested the crankshaft position sensor and it was grounded when it shouldn’t have been…? At this point I’m thinking it is definitely electrical. I am so baffled by this car!!