VSA fault 83-01

[honda_saj]

You still getting dtc 83-01 ?

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[mace]

I was last time I checked, yeah.

 

[freddofrog]

Resurrecting this.. still have the fault, haven't yet been able to figure out what's causing it..

However, I came across this post: https://answers.yahoo.com/question/index?qid=20090401182642AAPN7aG

Yahoo, so dubious provenance, however the suggestion is that a misfire could be involved.

Now, I have seen the occasional misfire via HDS, and the timing chain is also somewhat stretched, so I do wonder whether there could actually be a grain of truth in that theory.

It's an interesting possibility, but, he does mention EGR and there's no EGR on the 2.4 .

Having read through all you've tried, I'd stick to the possibility of a CAN fault somewhere. I wish the ESM had a better menu system for diagrams.

 

[mace]

So, time passes, and things got curiouser and curiouser.

Lent my car to a mate whilst his was on my driveway in pieces, and he brings it back a week later and casually notes that 'the engine light is off now'.

I check it, and he's right, it's out. And cruise is back in action again. Decided not to look that particular gift horse in the mouth, so ran with it for a few weeks, and all lights stay off.

However, went to start it the other day, and.. it fired briefly before deciding sod that and shutting down. After that wouldn't start without giving it throttle, and even then it barely manages a very rough idle.

My suspicion is that when he borrowed it, at some point (probably start up from cold) it jumped a tooth on the timing chain, putting the timing almost back to some semblance of normality. Then the other day when I tried it on a cold morning, it hopped another tooth, throwing it way out of spec, so it gave up.

Guess I'll need to tear it down and rebuild it at some point - any good stock rebuild threads on here (or elsewhere)?

Back to the theory about engine warnings locking out the VSA though; not definitive but this does tend to suggest I was along the right lines with that.

 

[freddofrog]

I've re-read that thread in #24, and also what you say about a misfire in #24.

One other possibility is that one of the coil-packs or spark-plugs might have been causing a misfire, but I don't get why all of them would now pack up, unless it's the outputs from the ECU (to coil-packs) that have died i.e. faulty ECU ?

If you want to check the chains, unlike the diesel engine, it's easy to remove the rocker cover. IIRC just remove the coil packs then move a pipe out of the way and the cover comes off, here was mine several years ago

You could get someone to crank the engine while you look at the cams and chain


btw the way, the auto-tensioner is down by the crankshaft pulley, there's a small cover over the tensioner (I've not removed it myself, you might need to drain the oil, but not sure about that).

 

[mace]

***uming the tensioner is somewhere vaguely sane (ie. roughly half way between the crank and the cams) then there shouldn't be sump oil anywhere near that level. Sump level should be below the level of all the moving bits on the crank.

I might pop the lid on it tomorrow and have a quick nose, trying to avoid getting too deep into it, as I've got too many cars in pieces at the moment and not enough room for the bits. Mind you it is a tourer, so there is a helpful flat surface back there.. hmmm.

Think I might have to find another copy of the workshop manual; I got one years ago on CD, but haven't a clue where it's wandered off to now, two house moves since.

 

[freddofrog]

Probably best to check all the plugs first, remove the coil-pack to get to each plug, then if the plugs look ok, you're already more than half-way to getting the rocker cover off.

 

[mace]

Plugs are fine, not smashed, always a good start.

Stuck a camera down each port, no big bits of debris kicking around in there. Doesn't mean valves haven't hit, but I can see the pistons are slightly pocketed (or is that big dents from valves - hope not).

Rocker cover off, can't see any coloured links on the chain, don't know if Honda bothered with such things.

I vaguely recall that at TDC cyl 1 (nearest the crank pulley?) the two cams should have their timing marks pointing at one another? If so, then it's fairly well fecked. Picture below, not sure if it'll show the marks sufficiently.

 

[freddofrog]

here is the guide for chain installation (hi-res, left-click to enlarge, or right-click to open in new tab)

and here are closeups of the relevant images (from 2 and 5 of the installation description)

I guess you need to make sure that the crankshaft is in the right position (cyl 1 TDC) then check the images

edit: obviously the coloured links won't line up unless you keep turning the engine many times (depending on #teeth and #links) and I've no idea if they're there any longer on the engine in my car. I do fancy taking the chain cover off mine, looks a lot easier to get in there than on the diesel.

 

[Jon_G]

The camshaft marks DO point at each other on the diesel at TDC. That may be where the misunderstanding arose?

The coloured links are not essential to getting the timing right.

 

[freddofrog]

The camshaft marks DO point at each other on the diesel at TDC. That may be where the misunderstanding arose?

The coloured links are not essential to getting the timing right.

here are the equivalent images for the diesel

 

[Jon_G]

Unfortunately I didn't need to see that drawing for proof!

Strange that Honda have this inconsistency in regard to setting up the cam timing. But at least having to align the coloured chain links with the relevant indentations is a sanity check, although I did discover that not all replacement chains come with coloured links...

 

[freddofrog]

well I thought it would make an interesting comparison

 

[mace]

Going by your pictures, this thing has jumped many teeth on the intake cam.

Exhaust cam is a little harder to see, but flywheel is at TDC (approx, just slightly past) and exhaust cam looks to be about right - hole at the top, line on the right.

Intake cam, line is almost at the top, and arrow is pointing right.

Suspect there is some piston to valve overlap too, as it gets very stiff to turn when it reaches TDC.

Slightly odd that the intake cam is the one that's skipped, since in theory the chain there will have constant tension from the crank. Theories on this welcome.

 

[Channel Hopper]

At this point I would be tempted to get a cheap compression meter, this will tell you all you need to know since just one off reading will identify if one or more of the cylinders have been playing 'valve, meet piston'.

All other options are going to be vastly more time consuming/ a money pit.

 

[Channel Hopper]

Going by your pictures, this thing has jumped many teeth on the intake cam.

Slightly odd that the intake cam is the one that's skipped, since in theory the chain there will have constant tension from the crank. Theories on this welcome.

I've seen this happen before on single cylinder motorcycles. The slow turnover with the starter can sometimes cause the unburnt fuel to detonate before TDC forcing the engine to turn backwards and slacken off the non tensioner side of the camchain, which then rides over the cog teeth

 

[freddofrog]

I'm not sure if it's possible, but the VTC might be incorrectly locked in that position

This explains the VTC on the engine
https://www.youtube.com/watch?v=OtRlQrAc5IY

 

[freddofrog]

also, was the engine producing a VTC rattle/grind when starting up ?

https://www.youtube.com/watch?v=JLqdLEmswn4

 

[mace]

Sounds like a reasonable theory Channel Hopper.

Freddofrog: Don't recall that noise, but then it was 5am, the bonnet was down and I wasn't listening for an imminent failure to chooch.

Re compression test, I'll probably do that and a leak down, but need to fix the timing first, otherwise it's not likely to yield useful results.

 

[freddofrog]

if the engine has a VTC issue, you should be hearing the noise well beforehand, usually on cold mornings

this is a better example of the noise

https://www.youtube.com/watch?v=i71NSY1I0iw


if you have never heard that noise, it doesn't mean there isn't a VTC actuator issue, but if you have heard that noise now-and-again, it does indicate a potential issue long-term

my money is it being a VTC issue, it's out by 90 degrees, I can't see it jumping that many teeth unless there is no longer any tension in the chain

 

[mace]

Quick google suggests the stock K24 has 25 degrees of advance, and those marks are around 90 degrees out, so I think we can rule out the mechanism being locked in the wrong place?

 

[freddofrog]

I think it's 25 degrees advance and 25 degrees retard and AFAIK it's supposed to be locked in the retard position at start-up, but I can't think why it would lock in the advance position

 

[freddofrog]

hmmm forget that, it wouldn't move like that on the chain anyway, it's the cam that moves relative to the sprocket ....duh :blush:

 

[mace]

That second video is much better, thanks; tentatively I'd have to agree it has been making that noise for a while on cold starts, or a similar noise - I'd just put it down to oil leaking back down to the sump and the pump taking a moment to re-pressurise the oil passageways to something that wanted lubrication.

It could be my tensioner has the common worn teeth fault - prior to oil pressure building up, if the teeth are worn it would be relying solely on the weak spring to stop the chain flapping about.

Is there a specification for how far the tensioner should be extended before chain replacement is required? A very rough measurement I did yesterday suggested it was extended to around 30mm, or there abouts.

 

[freddofrog]

Is there a specification for how far the tensioner should be extended before chain replacement is required? A very rough measurement I did yesterday suggested it was extended to around 30mm, or there abouts.

I'll have a look, but 3 cm sounds a lot to me

btw I have also read elsewhere that that noise in #50 is also due to a stretched chain or a faulty tensioner

 

[freddofrog]

I've seen it for the diesel but not for the K24 and now I can't find either :mellow:

but the compression should be 135 psi minimum with 28 psi max variation between cyclinders

 

[mace]

Thanks; I'll probably need to wait until tomorrow for an extra pair of hands to take the tension off the chain and fettle the intake cam back to something approaching normality. Then I'll run a leakdown test, and finally attempt a compression test.

Do you know if the fuel pump fuse is in the interior fuse box? Didn't spot it from a quick glance of the engine bay fuse box yesterday, but wasn't trying very hard.

 

[freddofrog]

According to the ESM, fuse 19 in the under-dash fuse-box

just another thought on what has happened, the intake sprocket (on the right) might have pulled the chain past ~10 teeth on the exhaust sprocket when the chain was slack at start-up ? ....but only if the crankshaft really is is not at TDC in the picture

If you open up the tensioner cover, you can remove the tensioner (by rotating crankshaft backwards to remove tension) . But when you put the cover back you have to wait 3 hours for the liquid-gasket to dry

Hopefully there's nothing bent

 

[mace]

According to the ESM, fuse 19 in the under-dash fuse-box

just another thought on what has happened, the intake sprocket (on the right) might have pulled the chain past ~10 teeth on the exhaust sprocket when the chain was slack at start-up ? ....but only if the crankshaft really is at TDC in the picture

If you open up the tensioner cover, you can remove the tensioner (by rotating crankshaft backwards to remove tension) . But when you put the cover back you have to wait 3 hours for the liquid-gasket to dry

Hopefully there's nothing bent

Ta on fuse location, saves me digging for a manual.


Crank pulley is at TDC for #1 (well just past it, because I suspect the intake valves are slightly hitting).

***uming the intake sprocket had pulled the chain over the exhaust sprocket, I'm struggling to think of a scenario where that would leave the exhaust sprocket roughly where it should be in relation to TDC #1?

I've got the tensioner cover off, that's how I made my rough measurement of extension. Don't really need to wait any time at all, just bolt it back on to keep chain from splashing whilst I turn it over on the starter. It's not like it's going to be a runner again before I change the chain, at minimum.

I'm also hopeful that nothing is bent - if so I'll probably have to wait until the Rangey is back on the road and go and pick up the spare k24 I bought a few years ago.

 

[Channel Hopper]

Sounds like a reasonable theory Channel Hopper.

Freddofrog: Don't recall that noise, but then it was 5am, the bonnet was down and I wasn't listening for an imminent failure to chooch.

Re compression test, I'll probably do that and a leak down, but need to fix the timing first, otherwise it's not likely to yield useful results.

I disagree. If the engine has been turned over after the first problem arose then you cannot do any further damage (unless the chain moves over more teeth). If there is no damage but the timing is out, then the cylinders should be showing roughly the same compression since the timing is the same on all, though the full number - 135 psi ? - will not be reached.

If one or more is significantly different to another then you know you need to take the head off.