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Black comedy of errors:ECU/sensor problem


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I'm not sure what has been the cause of the damage to these things but some members here have had to replace them for the same problem you are having. Hopefully yours is ok but from what I have seen in the posts so far on this, I think this is the best explanation for the problem.

 

I don't think a puller is needed to remove it if that is needed but I haven't replaced one myself. There are some more knowledgeable members here that do know.

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You just need to get the crank pulley bolt out and get the crank pulley off. Then get the outer timing belt covers off. Then you can inspect the crank sprocket. If it needs to be replaced, you can either remove the timing belt, or if you can just get enough slack by removing an idler or two that will work.

 

The crank sprocket just slips over the crank snout and sits on the keyway between the oil pump and crank pulley. It just slides on and off, at least mine did.

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You just need to get the crank pulley bolt out and get the crank pulley off. Then get the outer timing belt covers off. Then you can inspect the crank sprocket. If it needs to be replaced, you can either remove the timing belt, or if you can just get enough slack by removing an idler or two that will work.

 

The crank sprocket just slips over the crank snout and sits on the keyway between the oil pump and crank pulley. It just slides on and off, at least mine did.

 

Hi,

 

I really REALLY just want to remove the crank sensor and have a look at it, my chilton says " 1) Disconnect negative batterycable.

2) Remove the timing belt."

 

Errrrrr why?

I am trying to pull the sensor out (after removing it's mounting bolt)...twisting wd40-ing... but no luck so far. is there a C-clip hold ing it in? tha is the only reason I can think of for removing the timing belt.

I really was hoping to not have to buy Haynes, as I want to sell this vehicle ASAP, not that it should make any difference here.... why the f@#)(*&^%$#@!! would they use an internal fastener seems overkill.

I am guessing it is just a tight clearance hole and that there is corrosion on the sensor preventing it form neatly sliding out.

 

my current theory is that the crank shft has devoloped play in the bearing and/or is a tiny bit bent.

This would account for the sinusoidally varying amplitude of the pulses I was getting from my scope. The tabs move periodically closer and further from the sensor, dropping below the threshold for detection by the ECU.

 

I was thinking I could "machine off" a few thousandths from the should of the detector, getting it a tad closer to the tabs(hopefully not banging into the tabs.)

I still can't imagine how the tabs could break off.... are they steel? or are they some brittle magnetic material? I suppose they could corroded and get shorter... but...

 

I just don't want to take anything apart and deal with more uncertainties...

I am just a bit lazy sort of stubborn and more than a little paranoid.

 

For example, the power steering pump looks like a biatch to take out without ruining the hoses.

 

Probably the broken tab theory is right...and I will have to do this anyhow.

Bill

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If you just want to look at the crank position sensor, removing that one bolt at the top of the oil pump that holds the sensor is all that is needed. There is no internal c-clip or anything like that. It is a little bit of a friction fit in the hole. If it's hard to get out you might be right about the corrison. Can it turn at all clockwise/counterclockwise to free it?

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If you just want to look at the crank position sensor, removing that one bolt at the top of the oil pump that holds the sensor is all that is needed. There is no internal c-clip or anything like that. It is a little bit of a friction fit in the hole. If it's hard to get out you might be right about the corrison. Can it turn at all clockwise/counterclockwise to free it?

 

 

Yeah, I can turn it...

 

But....

I started going for the timing belt cover.

I am about to fashion some manner of big strap wrench to hold the crank pulley while I loosen the crank nut.

 

I have a steering wheel puller somewhere, I hope I don't have to buy a special puller for this job.

 

if there is so much corrosion BEHIND the belt cover that I can't remove the sensor w/o getting medi-evil.... it is probably worth a look behind there.

 

I am finding that I don't have a stumpy enough socket to loosen one bolt for the A/C bracket the intake manifold is too close... I am hoping I can get the cover off w/o removing A/C.

 

Bill

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There's a number of ways to hold the crank pulley still while breaking loose the crank pulley bolt. Big chain wrench, the starter bump trick, screwdriver into the flexplate teeth, wrench on cam flats, etc. If you happen to have an MT, it's easy; just put 'er in 5th and have someone stand on the brake.

 

Also in case you don't already know, these bolts sometimes back out after reinstall if not torqued correctly. I think some earlier books had too low a torque value.

 

After the bolt is out, sometimes just wiggling the crank pulley is enough to get it off the snout. If it's corroded on or something then maybe you need to pull it somehow.

 

I think you will have to get the a/c tensioner bracket out of the way; otherwise probably can't the outer middle timing belt cover over the crank snout.

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I have a steering wheel puller somewhere, I hope I don't have to buy a special puller for this job.

 

 

 

I have to buy a special wheel puller!

 

 

probably a good thing to have around....

 

Nipper: you have one you can lend out?

 

I will see what they $want for it. I hate tools that are only good for one thing.

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Before pulling things apart I was wondering if you first verified the CPS signal is bad (missing a pulse) using your scope.

 

You talked about a sine wave distortion in the signal. I suspect that may be due to some AC hum you are picking up. You could verify that by measuring the time period of the waveform and then take the reciprocal of the time period to get the frequency. I think you will get 60Hz.

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What kind of special puller do you mean? SPX makes the special service tools to hold the crank pulley in place while breaking the bolt loose, but there are alternatives.

 

I made a strap wrench and backed the bolt out.

 

Chilton say therei s a crank puller tool. you have to get it from Subaru, so I bought a couple things with which I might get it off...

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Before pulling things apart I was wondering if you first verified the CPS signal is bad (missing a pulse) using your scope.

 

You talked about a sine wave distortion in the signal. I suspect that may be due to some AC hum you are picking up. You could verify that by measuring the time period of the waveform and then take the reciprocal of the time period to get the frequency. I think you will get 60Hz.

 

No, it was roughly the cranking frequency, i was looking a 500msec, per division.

I was getting 3 pulses and a space which is normal from my understanding...but the amplitude was quite variable. I am hoping I find damaged tab(s)....

What do these crank sprockets go for (roughly) new/used?

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Hi all,

This is a continuation of my previous thread about my 2.2 legacy burning xistors/ignitors.

 

 

help, this is driving me up a tree.

 

.

 

OK,

so now I have some pics for you folks

 

 

Subarutimingbelt070207003.jpg

 

Tensioner/idler looks like it has a problem.

 

Subarutimingbelt070207020.jpg

 

The last place that worked on it replaced the timing belt after a breakdown....

They probably forgot to torque down the bolt on the tensioner. The bolt is broken off inside the motor. I am not sure how much is missing. I plan to drill and then use an easy-out. I will have to remove the radiator.

 

Subarutimingbelt070207018.jpg

 

The mounting stud pictured below is where the rest of the bolt lives.

 

Subarutimingbelt070207019.jpg

 

Turns out the timing belt was done about 10k miles before this happened.

The tensioner wheel spins free and looks in good shape, just the bolt is broken and the timing cover is scored. I am not sure if/how this explains the weird sensor readings. I never checked the timing because the the part of the timing belt that was exposed by the side cover was seemed tight.... maybe the timing is off by a few teeth. I am done for today. tomorrow I will be able to get a better look once the radiator goes away.

 

Any advice? I looked over the timing belt and it seems ok, I will look more.

the sproket looked ok... I will look it all over tomorrow..

 

The bad thing is that WHEN this car died, it was still under warranty from that repair.... I was thinking the Tbelt was done a month before it died, turns out it was ten months, 10k miles before then...... we had a 12 month 12k mile warranty .....

geez

 

Bill

We were actually moving that week, I had no way of working on it then.

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OK,

so now I have some pics for you folks

 

That is interesting. The thing I'm struggling with is understanding how this managed to fry the ignitors! I've never heard of an engine jumping time and causing ELECTRONIC damage. Perhaps the bolt head floating around caused some damage to the sprockets or cam/crank sensors. Or the timing jumped in just the exact right way to confuse the ECM big time. Keep updating us...this is turning into a real page turner...

 

Nathan

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OK,

so now I have some pics for you folks

 

That is interesting. The thing I'm struggling with is understanding how this managed to fry the ignitors! I've never heard of an engine jumping time and causing ELECTRONIC damage. Perhaps the bolt head floating around caused some damage to the sprockets or cam/crank sensors. Or the timing jumped in just the exact right way to confuse the ECM big time. Keep updating us...this is turning into a real page turner...

 

Nathan

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eeeek

 

Somewhere i wrote how i found that the ignitors were OK....forgive my stupidity, I misinterpreted the no start and no spark on one side as a bad ignitor, unbelieving the ECM could be bad, not even aware that the sensors could cause a no spark condition. The ignitor seems shorted to me cause I was reading a voltage drop from the base to both outputs even though one was about twice the drop.... I am assuming they they are fine now ( all three ignitors I own, 2 ECUs, 2 coil packs) I have written quite a bit here ...I can't blame anyone for losing track!

I was starting from scratch figuring this one out... I haven't worked on non distributer cars before... been quite a 'learning experience' LOL

 

I will fix the idler, make sure timing is right, retest sensors and maybe replace the crank sprocket...maybe the timing belt wandered and bent a sprocket tab(?).....can a miss-timed motor fire only on one side?

 

You know, I am realllly confused about this mess, but, I feel good in that there is something I CAN fix and hopefully get closer to an answer.

 

any suggestions are welcome!

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THe piece that the idler/tensioner bolts into is not part of the block. If you look to the right of the spot where the tensioner bolted, there is a 12mm bolt head, remove this bolt.

Right above the tensioner, on the outside of where the timing belt covers mated up is 2 more 12mm head bolts, about an inch apart. remove these, and the cast aluminum bit that the tensioner pully and tensioner cylinder attached to will come off.

 

Do the same to a junkyard car, and you're good to go, no tapping needed.

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Very good pictures Bill but that is pretty ugly looking in there. You made a good decision in getting inside and checking things. It certainly needs attention.

 

It is hard see the tabs on the crank sprocket in the picture. I can make out two of them. It almost looks like there is a broken section just to the right side of the sensor. Please get us a good picture of the spocket tabs when you get it off.

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THe piece that the idler/tensioner bolts into is not part of the block. If you look to the right of the spot where the tensioner bolted, there is a 12mm bolt head, remove this bolt.

Right above the tensioner, on the outside of where the timing belt covers mated up is 2 more 12mm head bolts, about an inch apart. remove these, and the cast aluminum bit that the tensioner pully and tensioner cylinder attached to will come off.

 

Do the same to a junkyard car, and you're good to go, no tapping needed.

 

 

 

ooooh i like that.

 

good news to wake up to.

 

Thanks my friend.

 

Bill

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I need a bolt.

The bolt pictured here:

http://catalog.drivewire.com/drivewire/baseline/quote-new.jsp?partner=drivewire&year=1990-1994&product=A5030-131787&application=247829&fm=1

 

for the tensioner.

 

I FINALLY got the radiator out...every thing with a thread was sort of a biatch.... the radiator expansion tank got most of my bad language,,, the bottom was really stuck...one radiator line is tranny fluid? or was that an oil cooler? I will look in the book tomorrow....It looked dirty, so, may as well put in some more of whatever it was. I then managed to get a 1/16th bit on my cordless drill and drilled into the bolt, which, as I figured probably would happen, it theaded the remainder of the bolt in. The small hole i made was big enough to accept the tip of an old drill bit I resharpened so that it bites in the reverse direction. I tapped it in a little and then backed out the broken bolt!

that was the high point of today....

I opted not to try and remove the bracket that the bolt was in, no junkyard within 40 miles carries that sort of thing. Plus I would rather not fudge around where I can barely see what will hang up on what...

 

But, I need a bolt... or a part#

Anyone wanna sell me this bolt?

any other part on this vehicle that uses the same bolt? my guess = NO

 

I get a feeling it may be a job to track down a source for "only" a bolt.

 

I plan on spraying a can or so of brake cleaner on the timing belt assembly and try and figure out if/how much the timing is off, I can see that the water pump was changed, the timing belt looks mostly ok... anything in the front of this motor I should take the time to check out or beware of before i reassemble?

 

I hope you all had a good 4th o July.

 

 

Bill

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Bill,

I'm sure any one of the various online Subaru wholesale parts places will be happy to sell it to you - the shipping will probably be more than the bolt, but so it goes. I've had good luck with these guys

 

http://www.subarugenuineparts.com/

 

Do you have a shop manual? The timing belt tensioner needs to be compressed very slowly in a vise and a locking pin inserted ( a drill bit works well). Might also be prudent to change the front cam & crank seals and O-rings, if they weren't done at the last T-belt service. Search for timing belt threads on here and you'll get better info than I can provide!

 

Nathan

 

 

I need a bolt.

The bolt pictured here:

http://catalog.drivewire.com/drivewire/baseline/quote-new.jsp?partner=drivewire&year=1990-1994&product=A5030-131787&application=247829&fm=1

 

for the tensioner.

 

I FINALLY got the radiator out...every thing with a thread was sort of a biatch.... the radiator expansion tank got most of my bad language,,, the bottom was really stuck...one radiator line is tranny fluid? or was that an oil cooler? I will look in the book tomorrow....It looked dirty, so, may as well put in some more of whatever it was. I then managed to get a 1/16th bit on my cordless drill and drilled into the bolt, which, as I figured probably would happen, it theaded the remainder of the bolt in. The small hole i made was big enough to accept the tip of an old drill bit I resharpened so that it bites in the reverse direction. I tapped it in a little and then backed out the broken bolt!

that was the high point of today....

I opted not to try and remove the bracket that the bolt was in, no junkyard within 40 miles carries that sort of thing. Plus I would rather not fudge around where I can barely see what will hang up on what...

 

But, I need a bolt... or a part#

Anyone wanna sell me this bolt?

any other part on this vehicle that uses the same bolt? my guess = NO

 

I get a feeling it may be a job to track down a source for "only" a bolt.

 

I plan on spraying a can or so of brake cleaner on the timing belt assembly and try and figure out if/how much the timing is off, I can see that the water pump was changed, the timing belt looks mostly ok... anything in the front of this motor I should take the time to check out or beware of before i reassemble?

 

I hope you all had a good 4th o July.

 

 

Bill

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That fluid you mentioned is tranny fluid to be cooled down by the heat exchanger in the radiator.

 

After looking at the condition of the timing belt parts, from the pictures you posted earlier, I think you would be wise to replace all the items with bearings in them. It may save you another failure item later on.

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Is that a regular hex head bolt or is it a flange bolt? Ace Hardware has metric grade 10.9 zinc coated hardware. If you can take the old one with you or measure it before going in you should be able to find one.

 

It's probably something like M12 at 1.25 or 1.5 mm pitch.

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Is that a regular hex head bolt or is it a flange bolt? Ace Hardware has metric grade 10.9 zinc coated hardware. If you can take the old one with you or measure it before going in you should be able to find one.

 

It's probably something like M12 at 1.25 or 1.5 mm pitch.

 

It has a flanged head, and, threads on about half of it.

 

I called one of the part suppliers in Milford Connecticut.... The guy says you can only buy the bolt WITH the tensioner idler assembly,

I ask why becase it LOOKS like only a bolt to me and he says something about it being "eccentric".... that would make no sense to me...

I am 98% sure he is wrong, ...... I thnk HE is eccentric, or, pathologically misaligned...and greedy to boot.

why can't he just say that they can't any make money off of selling bolts, so they do not carry them.... instead i get a mechanical fairlytale from a sales dork.

 

I might just check out a hardware store.

 

Thanks

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Look at the unthreaded portion (shoulder) of the bolt. Is it perfectly round like the rest of the bolt? If it is not round, then it is eccentric. Eccentric bolts are like those on the strut to housing upper bolt for camber adjustment. I can take some pics later if desired.

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