[97 obs rebuild]

picked up a car that had been sitting nearby for a long time. will crank fine, old fuel is pushed, sounds normal just not catching. appears no spark until i let go of key. obd2 codes for cam and crank position sensors p0336 p0341. begin measuring voltage and resistance all over.. i see continuity from the ecu connector to the sensors and both sensors test at about 2000ohms which is within subaru spec.. 1-4Kohm?..

has anyone seen these test good and then replaced it and had it work?? i know their not too expensive but some of the point of fixing this is troubleshooting practice. i dont have a backup ecu to verify the one in the car. should probably just replace these parts anyways as part of upkeep/restoration. not expecting too much from writing my diary.. i mean this forum

 

[97 obs rebuild]

also when i read obd2 using torque on android at standstill it reads 25rpm?? when cranking it goes up to 250+rpm.. i feel like i should replace the sensor even though it ohms good and keep cleaning grounds around the chassis especially the ecu

 

[Captain Kirk]

Interesting that you are seeing both of those codes with the sensors reading within spec. It may be worth checking the two main engine harness connectors on the passenger bell housing, make sure contacts are clean and that nothing is damaged.

 

[silverton]

I've had sensors spec good but be bad. Is your battery holding at least 10.5v while cranking? ideally 11+ but we can't have every thing we want. If you have a good battery, I'd recommend replacing both of those sensors.

I would not use torque has an end all be all diagnostic tool, it was a pain in the ass to tune my na+t car because at random it would spike the gauge i was monitoring to it's max reading, which throws tuning accuracy out the window. You should instead find a 32-bit laptop running windows xp, acquire a 'vagcom' cable, and use ecuexplorer software, IF you want to accurately monitor available engine data. you'll still likely need to keep torque for trouble codes. I was only able to check my impreza's codes using ecuexplorer after applying an update while i worked at the dealer.

 

[97 obs rebuild]

okay i have been looking for an excuse to get an old windows laptop. i will try a knockoff vagcom and torrent some software and a key. i replaced the crank sensor with a cheap piece from oreillys and no difference. measured about the same resistance so i assume this isnt the root of the failure. i have gone through the machine and cleaned all grounds and reinstalled with terminal protector so i am also suspecting this isnt the root cause of failure. will pickup a cam sensor right now and try that.

again my obd2 is just held at 25rpm when the machine is dead........ it does measure an increase to 2xx rpm when cranking so i feel like its working somewhat?? it at least measures a difference in one rpm and another..

 

[97 obs rebuild]

okay... replaced the cam position sensor with some cheapy from oreillys (they had it in stock NOW) and it finally kicked over and ran by itself. i am SOOOO curious my off speed still says 25rpm??? it only ran for a second but the intake isnt installed as its healing from my breaking that fitting again and doing another repair with way more jb weld.. also fuel lines have been cracked and was just on a tiny lithium 12vdc source but it did run by itself and sounded great as in no terrible banging 😀 i will pop it all together tomorrow. not a hard problem i guess. disappointing the factory manual guidance doesnt steer you 100 percent correctly. i will prpb still get the vagcom and am now wondering what is the best management tooling. i see subie made some sort of scanner with cartridged like a gameboy back in the day 🤣 japanese as fudge

 

[silverton]

there is no software to torrent, ecuexplorer is free. SSM1 through 3 all used cartridges. I updated my Impreza's ECU with a gameboy cartridge, as you say. SSM4 is a pc program, and was never too happy communicating with Subaru's older than 2006. One reason why scanners have a hard time with subaru PIDs and occasional erroneous data is because subaru uses their own protocol

 

[97 obs rebuild]

dang im so ashamed a lowly parts swapper am i and it went wrong because of my superior ineptness!! put it all together and it doesnt fire...... same codes related to crank and cam sensor.. will pull intake manifold and go through wiring as there was a rodents abode under there when i picked this old one up. check connectors closely et cetera

 

[97 obs rebuild]

there is no software to torrent, ecuexplorer is free. SSM1 through 3 all used cartridges. I updated my Impreza's ECU with a gameboy cartridge, as you say. SSM4 is a pc program, and was never too happy communicating with Subaru's older than 2006. One reason why scanners have a hard time with subaru PIDs and occasional erroneous data is because subaru uses their own protocol

whoa you have thee knowledge set on these vehicles i wish i had it seems! i am picking up an old laptop and a vagcom knockoff cable for now. the subaru smart select seems a bit high of a price for this one vehicle this one time. i will attempt further troubleshooting with a meter and manuals. i have a 1998 factory manual for my 97. also im a dirty dirty talentless parts swapper who uses the lamest excuse of "it needed it anyway" 😓

 

[dtuyen]

I would start taking a look at a wiring diagram and start checking for power and grounds at the harness and ecm. Not sure if they share a common circuit but it might be what's causing the fault if that's the case if especially there was a rodent infestation previously where they might've gotten to the wires.

 

[silverton]

whoa you have thee knowledge set on these vehicles i wish i had it seems!

12 years will do that. When you say it ran with the intake off, do you mean the intake manifold or...?

Unfortunately there is not much in the way of diagnostics for either of those codes. From Subaru, if either of those codes are set, it says to replace the respective sensors. If you only replaced one of them, I'd do both.

 

[97 obs rebuild]

12 years will do that. When you say it ran with the intake off, do you mean the intake manifold or...?

Unfortunately there is not much in the way of diagnostics for either of those codes. From Subaru, if either of those codes are set, it says to replace the respective sensors. If you only replaced one of them, I'd do both.

both sensors replaced and no difference. im the $#I##iest "troubleshooter" that has walked this earth. i had everything before the throttle body removed and i thought it farted over for a second. i put everything back together and no joy, just cranks and cranks and cranks with the original codes. i have ohmed out the wires and they seemed fine.. pulled the intake to examine the harness closer to see if the original rats nest i removed had damaged the wiring but there appear to be no errors on visual inspection and again ohming it all out... pulled the ECU as well and will inspect it internally as the car was essentially a humid terrarium when i got it.. and will disassemble and clean up the intake and paint it.. probably blue. cause that adds at least one or two horses. more if theyre those tiny horses.

i have a windows 7/10 pc coming with a knockoff vagcom and will inspect signals when it gets here.. very disappoint so far

 

[97 obs rebuild]

ecu visual if that is werth anything, nothing appeara shorted or fried.. no bulging caps.. no signs of overheat or smoke/soot.. im pretty much a scientist right now but im guessing the ecu is okay.. so double you tee effe.. circuit test good.. sensors test good and swapped in another good test set.. and ecu appears fine......... i will distract myself cleaning up the car while waiting for the windows PC and cable.

 

[97 obs rebuild]

reading around i found mention of 25rpm being the default rpm on these machines from the computer?? is this correct?

searching the same engine codes on this forum i found another user who had the same experience and their belts had jumped and the timing was incorrect on the motor.. these years are interference motors.. but when cranking i do not hear anything abnormal. i will check the timing tomorrow.......................

 

[97 obs rebuild]

just a follow up for anyone in the future i assume the root cause of failure is the machine being out of time or jumping a tooth or two on the belt 😁

 

[97 obs rebuild]

another followup the reason the timing jumped is because the tensioner is toast. diagnosong further and found the cam/crank codes again.. inspect timing and it has jumped on tooth on the driver side cam. new tensioner and timing and onwards 😀

 

[silverton]

one tooth wont cause damage, and it should still start. have you performed a compression test yet?