nelstomlinson Posted February 6, 2023 Share Posted February 6, 2023 Put together an EJ25 engine for my '02: rebuilt short block from Subaru, reliable machine shop went through the heads. I assembled it and stuck it in the car, and it refuses to start. It has ~150PSI compression on all four cylinders, pulled the fuel line between filter and engine, it squirts fuel. The engine was running OK (except for the fatal timing issue) when I took it apart, so I assumed everything attached to the intake manifold was OK. I cranked and cranked, and it occasionally coughed but never caught, even when I tried starting fluid. When I pulled the plugs to check compression, I found the two front plugs had wet, black fouling, the two back plugs were clean. Any ideas what to check, and how to check it? Quote Link to comment Share on other sites More sharing options...
Daskuppler Posted February 6, 2023 Share Posted February 6, 2023 Sounds like spark to me. Do you have spark on all 4 plugs? Is the ignition coil good? Wires? Etc I'm guessing timing is dead on, but I supposed being off a tooth might cause problems without destroying the engine again. Quote Link to comment Share on other sites More sharing options...
lmdew Posted February 6, 2023 Share Posted February 6, 2023 Timing! Electrical Connections Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 6, 2023 Author Share Posted February 6, 2023 Still cranks and coughs, but won't start even with ether. The manual says that the primary side coil resistance should be 0.73 Ohms, terminals 1-2 &3-4. I'm reading open circuit on the primary side. The secondary side reads 12.x KOhms, as the manual says it should. My junkyard spare coil, pulled from a running engine, gives the same readings. The odd thing is that the timing light will indicate spark as I crank. I wonder if a very weak spark could trigger the light without igniting the mixture? Quote Link to comment Share on other sites More sharing options...
Numbchux Posted February 6, 2023 Share Posted February 6, 2023 You have compression, and it won't run on ether? Your ignition timing is off. Did you use the original crank and LH cam sprockets? These have the tone wheels for their sensors, and there was a change about that vintage. Pull the timing covers and verify cam timing. Check the trouble codes. Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 6, 2023 Author Share Posted February 6, 2023 I did have to use a new crank sprocket. I made sure to compare it to the old one, the tone ring looked identical. I did use the same LH cam sprocket. We used a Mitsuboshi timing belt, and double checked that the marks on the belt were lined up with the marks on the sprockets. It seems like it _shouldn't_ be off. I'll hook up a code reader, and see if it shows anything. How do I check the cam timing? Am I looking for the arrow on the LH sprocket to be straight up when the harmonic balancer mark is on zero? Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted February 6, 2023 Share Posted February 6, 2023 (edited) belt marks are unlikely to line up (maybe every 200+ turns?) but, if you align the crank and cam pulleys to the belt install marks, use a tooth count (look on-line) for your engine to double check timing. if you pull plugs and they are wet, maybe try the 'clear flood' procedure; crank with the pedal on the floor. Edited February 6, 2023 by 1 Lucky Texan Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 6, 2023 Author Share Posted February 6, 2023 The stored code is Crank Position Sensor, the pending code is Cam Position Sensor. From memory, P0336 and P0341. I wonder if I should try replacing both, just to be sure one hasn't failed. I found the tooth count in the manual, but the rim on the edge of the cam sprockets kept us from counting the last half-dozen-ish teeth. The count looked close, at least. Like I said above, we lined up the marks on the belt with the marks on the sprockets. If we pull the engine and re-install the belt, what could we do differently this time? Quote Link to comment Share on other sites More sharing options...
el_freddo Posted February 7, 2023 Share Posted February 7, 2023 I’d be investigating those crank and cam angle sensor issues before pulling the engine out. It’s very rare that one or both sensor died - but if they were dropped it’s possible to damage them. Make sure they’re properly plugged in too, and that it’s the correct wire that’s plugged in - I recently read about an injector plug being connected to the crank or cam sensor (can’t remember which one). Also, ignore the arrow on the cam wheel as this is not used for timing. Use the little tab mark on the rim of the cam wheel. From memory the arrow should be pointing at the 1:30 mark. That arrow is there to indicate which cylinder is at top dead centre through the engine cycle. Cheers Bennie Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 7, 2023 Author Share Posted February 7, 2023 Napa had the crank sensor in stock, they'll get me the cam sensor tomorrow. I tried it with the new crank sensor just now...didn't start, but the codes didn't come back, either. Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 7, 2023 Author Share Posted February 7, 2023 We didn't use the arrow when we installed the belt. We put a timing belt in an '08 a few weeks back with no drama, this went exactly the same, near as I can recollect. They do use different belts, which sorta surprised me. Quote Link to comment Share on other sites More sharing options...
lmdew Posted February 7, 2023 Share Posted February 7, 2023 Top is Passenger side Middle shows both crank gears Bottom is Drivers side Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 7, 2023 Author Share Posted February 7, 2023 That surely looks like what we did. Only thing it doesn't show is the marks on the belt. 1 Quote Link to comment Share on other sites More sharing options...
el_freddo Posted February 7, 2023 Share Posted February 7, 2023 Other thought is whether you have the spark leads on the right spark plugs… Cheers Bennie 1 Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 7, 2023 Author Share Posted February 7, 2023 Front left terminal to front left plug, and so on. Maybe I should try switching them up, back to front, just for kicks. Quote Link to comment Share on other sites More sharing options...
brus brother Posted February 7, 2023 Share Posted February 7, 2023 numbers are printed on coil Quote Link to comment Share on other sites More sharing options...
brus brother Posted February 7, 2023 Share Posted February 7, 2023 2 hours ago, nelstomlinson said: Front left terminal to front left plug, and so on. Maybe I should try switching them up, back to front, just for kicks. did you put the engine in backwards? 😉 Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 7, 2023 Author Share Posted February 7, 2023 Backwards and upside down, but the two should cancel out, right? Yeah, numbers are on the coil, and I wrote the numbers on the plug wires with sharpie when I installed them. 2 Quote Link to comment Share on other sites More sharing options...
heartless Posted February 7, 2023 Share Posted February 7, 2023 48 minutes ago, nelstomlinson said: Backwards and upside down, but the two should cancel out, right? Yeah, numbers are on the coil, and I wrote the numbers on the plug wires with sharpie when I installed them. what kind of wires??? plug wires should be OEM or NGK only - anything else is a waste of your money. cheap parts store wires on junk for these cars. I agree with the others about verifying timing (by tooth count if at all possible - get a silver sharpie and make your own marks), set the timing mark on the crank in the correct position and check the cam marks to make sure those are correct... with a new belt (no stretch) on both my 02 and my 04 models (both EJ251) the drivers side cam mark was ever so slightly turned in towards the center when the belt was installed correctly - and i mean VERY slightly - barely noticeable.. if one is slightly outward, you are a tooth off. triple check all electrical connectors - make sure they are fully seated and locked in - and in the correct positions. also worth going back over everything to make sure you didnt miss connecting anything... Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 8, 2023 Author Share Posted February 8, 2023 Plugs and wires are both NKG, they really don't cost much more than the cheap stuff. 2 Quote Link to comment Share on other sites More sharing options...
Daskuppler Posted February 8, 2023 Share Posted February 8, 2023 Plus one for the timing at this point. One cam doesn't quite line up, maybe half a tooth. It's very obvious if you push the cam the other way though. The driver side cam is under compression when set properly and can easily shift a little while you are getting the belt on and set. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 8, 2023 Share Posted February 8, 2023 On 2/6/2023 at 9:37 PM, nelstomlinson said: That surely looks like what we did. Only thing it doesn't show is the marks on the belt. Belt marks aren't needed as long as cams and timing cover marks are perfect. 1. Why did you have to use a new crank sprocket? Is there some damage or issue that might help us in this saga? A. Unplug the cam and crank sensor connectors, see if pins are compromised and ensure they're fully seated when plugging back in. B. Verify the correct timing marks were used and they're alignment is correct. C. Check the cam and crank sensors for damage to the sensor, connector, or wiring. If still striking out - verify the crank sprocket you swapped is the right one (there are two for that year). 1 Quote Link to comment Share on other sites More sharing options...
nelstomlinson Posted February 8, 2023 Author Share Posted February 8, 2023 The old short block had the keyway get ruined, so crank, sprocket and harmonic balancer all had to be replaced. So, a new short block and new sprocket. I compared the old and new sprockets, they have the same number of teeth, and the tone rings look identical. I'll replace the cam and crank sensors this weekend. If that doesn't do it, we'll pull the engine and try reinstalling the belt, I guess. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted February 8, 2023 Share Posted February 8, 2023 1 hour ago, nelstomlinson said: we'll pull the engine and try reinstalling the belt, I guess. Ah, got it. No need to pull the engine, timing marks can be inspected in half an hour. Quote Link to comment Share on other sites More sharing options...
nvu Posted February 9, 2023 Share Posted February 9, 2023 Just for kicks, try starting it with the maf sensor unplugged. 1 Quote Link to comment Share on other sites More sharing options...
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