~Slideways~ Posted November 28, 2021 Author Share Posted November 28, 2021 Came out pretty good, not perfect but much better than it was, difficult to paint on the hoist but it's wof'd again. 7 Quote Link to comment Share on other sites More sharing options...
Popular Post ~Slideways~ Posted December 9, 2021 Author Popular Post Share Posted December 9, 2021 Love driving this thing, work commute: EDIT: photo taken from my desk so excuse the zoomed in blurriness 12 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted December 28, 2021 Author Share Posted December 28, 2021 Hmm interesting, looking at the TPS log it sometimes does this around 7% throttle. But only sometimes. It seems to be around 7% throttle, which is probably around where it would be to maintain speed at 50kph. It's only a 0.2% fluctuation, but anywhere else it's rock solid. You can see I changed to just above 8% and it's a straight unfluctuating line. I tried a few times and sometimes it's accurate but when it fluctuates it stays like that. This is without the engine running. A new TPS is quite expensive because it's unique to this cable throttle vvti motor. Still available though. Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted December 28, 2021 Author Share Posted December 28, 2021 Here it is again around 6.7% Not sure it's enough to cause the misfiring but it does seem to be around where I've been experiencing the problem. Doesn't explain why when it's misfiring it still does it with more rpm and no load, but stops as soon as it drops to idle. 1 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted January 20, 2022 Author Share Posted January 20, 2022 Bought new genuine Toyota TPS. The one that came off doesn't have any markings which is interesting. Old on left and new on the right: Put it on and drove it to work which is about 40min, trying to make it misfire, was perfect the whole drive. Thought it was solved. Drove it home and it misfired twice. Same behaviour. I guess I can cross it off the list though? 1 1 Quote Link to comment Share on other sites More sharing options...
Roman Posted January 20, 2022 Share Posted January 20, 2022 See what other voltage related things you can pull up on the log, and see if they fluctuate So 5v sensor supply, see if its stable Battery voltage, see if it fluctuates See if any other sensors that share the 5v supply fluctuate as well 2 Quote Link to comment Share on other sites More sharing options...
tortron Posted January 20, 2022 Share Posted January 20, 2022 are there any plugs that the 12v systems and 5v systems share? just comes to mind as thats what hyundai key fobs use, the 12v to the ign and 5v to the sensor ring share the same plug and they fail because the plug is built for 12v, so when it gets a bit of corrosion on it the 5v gets iffy, working sometimes, sometimes needing a jiggle. Fix is to cut the wires and solder the 5v signal together 1 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted June 27, 2022 Author Share Posted June 27, 2022 Put this back on the dyno last week to redo the boost table since last time, which was about a year ago, it was found that the little filter thing on the solenoid is quite restrictive. So it wouldn't allow enough air to be bled for more than 16psi. On the street it goes great on wastegate pressure which is 10psi. Got the call that after 20 runs it started running on 5. Big puff of blue smoke (think there might have been a noise...can't remember the exact description). Compression test showed zero compression on number 4. Leak down test is pushing air back into the intake manifold so it has to be an intake valve problem. Nothing excessive out of the oil filler hole. The spark plug does not show signs of running lean. No knocking or metallic noises. Obviously not what I'd hoped for but that's where we are. Had a big think about it and am wondering if there has been an issue with one of the intake valves since day one. It could explain the intermittent misfire which the long list of things I've tried has not resolved. i.e. something making that valve not seal sometimes and is now worse. Got it home on the trailer a few days later. It runs on 5 with no bad noises except sounding like a Subaru. So I decided to compression test number 4, and from stone cold it immediately made a decent amount of compression? Not zero. I didn't take note of how high it went but it shot up and held it after just the first few turns. OK, so I put it back together and start it up thinking maybe the theory of an intermittently sealing intake valve makes some sense now. It still ran on five, I double checked the injector/coil plugs etc. So I compression tested number 4 again and now it makes zero compression like had been reported at the dyno. The needle barely moves. OK. Interesting. So while this has all been quite disappointing to say the least, I am looking on the bright side, getting angry at it won't fix it. The bottom end is hopefully undamaged (hoping a piece of valve hasn't dropped into the bore, because it was able to make some compression at first). No bad noises. Could it be the spring is bad? The valve spring seat/keepers are loose? Worst case, something melted causing damage to both the head and bore. Middle case, damaged valve. Head comes off and rebuild it. Best case, a replacement valve spring/keepers/seat solves it without taking the head off. It'll be a while before I have time to look at it now but am keeping my fingers crossed. Still looks cool though right? 9 Quote Link to comment Share on other sites More sharing options...
tortron Posted June 27, 2022 Share Posted June 27, 2022 Check the valve clearance on that one, is it excessive? Might be binding in the guide in certain positions Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted June 28, 2022 Author Share Posted June 28, 2022 3 hours ago, tortron said: Check the valve clearance on that one, is it excessive? Might be binding in the guide in certain positions Yeah definitely will be interesting to see if there is a bigger gap, binding could explain it. That's definitely better than the alternative of the valve being damaged because I'd want to know why it happened. Quote Link to comment Share on other sites More sharing options...
mjrstar Posted June 28, 2022 Share Posted June 28, 2022 Could be a valve bucket jamming in the head I reckon, or a dodgy shim. I'd pluck the cams out and check for that before digging any deeper. The 2jz is known to be a bit lacking as far as camshaft lubrication goes to.. So could be a cam journal issue (hopefully not though) 1 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 7, 2022 Author Share Posted July 7, 2022 On 28/06/2022 at 16:05, mjrstar said: Could be a valve bucket jamming in the head I reckon, or a dodgy shim. I'd pluck the cams out and check for that before digging any deeper. The 2jz is known to be a bit lacking as far as camshaft lubrication goes to.. So could be a cam journal issue (hopefully not though) I've come across some old forum posts talking about 2jz's having buckets get stuck so this is definitely a possibility, I'll hopefully get into it soon. Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 9, 2022 Author Share Posted July 9, 2022 Have pulled the intake side cam cover off and on number 4 the clearance on both shims is the same and within factory spec of 0.15mm to 0.25mm. Turned it over with the key a few times to see if there was any sign of a bucket getting stuck and it looks totally fine. Compression tested number 4 and it's got nothing, to confirm I tested number 3 and it has good compression. So that at least tells me the bucket isn't getting stuck and keeping the valve open, because its all the way up and there is no compression. Next I'll take the intake manifold off and see if it's possible to see the back of the valves. 7 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 10, 2022 Author Share Posted July 10, 2022 OK got the intake manifold off and first thing I notice is that number 4 intake port has a decent pool of oil. The other 5 are clean and dry, so that isn't a good sign. EDIT: unless they put oil down the spark plug hole to confirm is the rings are gone? Not sure they would have. So is this coming from a buggered valve stem seal or sucking up past the rings, explaining the lack of compression. Removed the second part of the manifold so I can see in the port, I can see a large area of the valve and they look super clean and I see no damage. But I cannot see the whole surface, its possible the inner edge is where the problem is. Very hard to focus when the valve is open. So the oil isn't a good sign, maybe it really is the bottom end even though the leak down test didn't indicate this. But I guess the next step will be checking the exhaust side or maybe taking the intake cam out and removing the buckets on the 4th one. 3 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 11, 2022 Author Share Posted July 11, 2022 Well this throws the intake valve idea out the window, as a test of the sealing of the intake valves on number 4 I squirted enough kerosene into the port to cover both valves and nothing drained away. You can kind of see the fluid here: So I took the exhaust side cam cover off and checked the buckets, they look to moving perfectly and the clearance is good too. Compression tested again and still zero. Squirted a bit of oil down the spark plug hole and it made no difference to the compression reading. So now I guess it is either the exhaust valves not sealing, the headgasket or the rings/pistons/bore. Won't be able to do anything on it for a while now but just wanted to try confirm what the problem was... I guess I've confirmed what the problem isn't. I suppose when the head is off it will make it obvious but I didn't want to take it off until I'd done some testing. Fearing the worst now, bore damage, broken ring lands, something went through and damaged the combustion chamber too. Confused how the leak down test indicated the intake valves on number 4 were leaking into the intake. Quote Link to comment Share on other sites More sharing options...
sheepers Posted July 11, 2022 Share Posted July 11, 2022 I got a hundred bucks on broken ring land. 1 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 11, 2022 Author Share Posted July 11, 2022 53 minutes ago, sheepers said: I got a hundred bucks on broken ring land. *Searches Real Street Performance... Quote Link to comment Share on other sites More sharing options...
mjrstar Posted July 12, 2022 Share Posted July 12, 2022 ^^it is starting to look like sheepers prediction, or maybe a bit of piston melting near the valve recess edge. Put air down the spark plug hole, with valves on compression stroke, see if air comes out the crankcase breathers or manifold. Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 12, 2022 Author Share Posted July 12, 2022 1 hour ago, mjrstar said: ^^it is starting to look like sheepers prediction, or maybe a bit of piston melting near the valve recess edge. Put air down the spark plug hole, with valves on compression stroke, see if air comes out the crankcase breathers or manifold. Yeah I guess I'll still check the exhaust side but either way the heads going to need to come off. Cars can be a bit of a dick sometimes 2 Quote Link to comment Share on other sites More sharing options...
~Slideways~ Posted July 23, 2022 Author Share Posted July 23, 2022 Took the exhaust side off and did the kerosene test there too and it looked fine. So took the head off and found this, fuck. Number 4 is melted on the exhaust side and pitted on the intake side. All the other pistons look fine. The headgasket looks fine too. So I'm guessing it went lean on just one. But was this a short term thing or long term? The bore has light scoring when the others don't. It feels smooth though so not too deep. You can see the exhaust side of the cylinder has a build up of what must be melted piston. It's like tiny bits of the piston built up since it protrudes from the cylinder wall rather than eaten into it. It does look to have removed a coating from the wall, not sure what's going on there. The same build up is on the head. It doesn't look to have eaten into the head material though. The head looks worse in the photo than it is. Hopefully skimming it will be enough. As you can see, the valves look good and were likely never the issue. So at this stage I am leaning towards the injector on number 4 having a flow problem. But am open to suggestions. At this stage I think I will go with oversized forged pistons and use the stock conrods since they are meant to be plenty strong for the kind of power I wanted from this. The intermittent misfire could be the cause, if I only knew what caused it, not from a lack of bloody trying... The same thing happened with the Xspurt 1000cc injectors and with the 550cc 3sgte injectors. Both of which had been through an injector cleaner. Swapping coils with a known good one made no difference either. Or it could be a faulty ECU causing the misfire. Maybe the intermittent misfire isn't the cause since it happened at light load. Either way it needs rebuilding, but how do I stop it happening again? 3 Quote Link to comment Share on other sites More sharing options...
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