Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 As title, anyone on here a 1j guru? Got a misfire thats driving me insane Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 6, 2015 Share Posted March 6, 2015 Nothing special about a 1JZ, it's a six pot petrol engine like any other and tracing a misfire is no different to tracing one on any petrol engine, so we need a LOT more info to help you. Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Sorry Chris I should have been more clear. I have had a misfire on my soarer ever since I fitted a full exhaust. New (recommended) spark plugs made the problem slightly worse but regapping them since made it better. Things that have also made it better is soldering new terminal connectors for the coil packs and epoxy and heatshrinking the coils. What should I be checking next? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 6, 2015 Share Posted March 6, 2015 Bung the tailpipe up with an old wet towel and see if you have any exhaust leaks up at the engine end. If air is getting in near the O2 sensor gear it will affect running and probably cause a misfire. Waggling the coil connections with it in idle miss mode should show up dodgy coil terminals. It's often the case people will spend hours and ££££'s just replacing stuff at random when £60 or so at a diagnostic garage would pinpoint the issue without recourse to a box of unnecessary, perfectly servicable used bits in a corner, and a rook of Toyota invoices And still a misfire! Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Thank you for the quick reply. Will the bung in the exhaust need to be on a cold start to see the exhaust gasses? Coil connectors are brand new soldered in this weekend. Quote Link to comment Share on other sites More sharing options...
Jellybean Posted March 6, 2015 Share Posted March 6, 2015 Will the bung in the exhaust need to be on a cold start to see the exhaust gasses? Just plug her up and let the gases build up , takes a few seconds , does not matter if it is cold start up If you have any leaks you will see the exhaust gases leaking out, Gasket area's are normally the culprit Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 6, 2015 Share Posted March 6, 2015 Juast listen for a blowing sound. Would need to be right up towards the front to affect the O2 reading though. A good garage with a scope on the ignition should be able to see if it's fuel or ignition issues in minutes. was the miss there before you did the coil connectors/ You know they need to be the right way around don't you? There's one wire that has to go to one side of the coil and one to the other, and it matters that they are to the correct terminals on each coil. Does it miss under load, driving it? is it a constant regular miss, or intermittent? Has it had a compression and leakdown test done? How many miles has it done? Is it stock? Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 The misfire has been there since the full exhaust system was fitted (the old one was blowing and I'll fitted). I changed the coil pack connectors and made a note of the wires orientation to ensure I had got them the right way round. It's an intermittent miss only on nearly full throttle and or high revs. Drives fine under 4.5k revs or so but never makes it to redline! This engines come from another soarer (so I was told) that had done approx 40k before I bought it. Engine milage approx 45-50k. It is stock apart from exhaust Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 And I hear what you are saying about a good diagnostic garage. Wish I knew one local! (Hertfordshire) Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Forgot to mention the engine light is on on some starts and the misfire is usually much worse when cold. When warmed up the warning light also tends to go away. I've done diagnostics but it's pretty simple on this car only a series of flashing lights which indicate an "rpm" signal error on start or idle Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 And I have error code 13 and 34 (yet to find a lookup for the latter) Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted March 6, 2015 Share Posted March 6, 2015 You might be hitting the fuel cut if the misfire is at high revs or full throttle. Especially if the new exhaust fitted is free flowing or you removed a cat or two. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 6, 2015 Share Posted March 6, 2015 (edited) I'd pull apart the connectors to the 2 cam sensors on the LH side of the head, and the crank sensor, spray them with WD40 and make and break the connectors again a few times to "wipe" the terminals. If that doesn't fix it you need to scope the cam and crank sensor signals at the ecu to see if there's a sensor fault. . You could also try removing, spraying and refitting the multi connectors at the ECU. You also need to check the cam timing and the cam belt, if it's worn, stretched or the tensioner is knackered it would show code 13 sometimes. My bill is in the post Code 34 is usually caused by over boost, probably because of the free flowing exhaust, for that you need one of my fuel cut defenders. £50 plus VAT and £5.80 insured P&P to a UK post code Edited March 6, 2015 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Thank you all very very helpful - will try all your suggestions! I actually have a boost cut controller lying around I haven't fitted yet. Cam belt and tensioner have been changed recently (before the exhaust was fitted). No reason to think the timings messed up currently but happy to be corrected if you think it's worth asking a garage to re-check? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 6, 2015 Share Posted March 6, 2015 It's easy enough to check the cam timing yourself if you have a 5mm Allen key to remove the spark plug /coil cover. Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Care to walk me through this? Could it have slipped? You have been so much help so far btw thanks! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 6, 2015 Share Posted March 6, 2015 Do a search, there will be the info you need where someone has described a cam belt change. It's a LOT of typing to re run through what's already on the forum Code 13 is your problem, the cause needs finding and addressing, that'll be your high load misfire. Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Okay cool I'll have a look thanks. What else could cause a code 13? Quote Link to comment Share on other sites More sharing options...
trebor69 Posted March 6, 2015 Share Posted March 6, 2015 I had a terrible miss on mine when I first fitted it and tried plugs, coil packs, sensors etc but was still the same....it seemed ok until about 3 to 3.5k revs then would splutter like crazy but only above these revs, eventually I remembered that when I bought it the guy told me that the cam belt had been changed prior to it being stood (it had been sat on a garage floor for four years) so I removed the top plastic cam cover and number one plug, placed a long screwdriver in number one cylinder and turned the crank to line up the timing mark on the crank pulley and top dead centre on first cylinder and hey presto .....the top cam gears were two teeth to the right !!!!!!! Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 6, 2015 Share Posted March 6, 2015 Sorry forgot to mention - the car revs in neutral or park all the way to redline with no misfire. It only misses under load... Is this therefore still likely to be a timing issue as timing is not affected by boost? Quote Link to comment Share on other sites More sharing options...
trebor69 Posted March 6, 2015 Share Posted March 6, 2015 Mine seemed to run fine in neutral but I don't remember revving it that high whilst sitting still.....worth checking anyway as its only a 15 minute job. Quote Link to comment Share on other sites More sharing options...
trebor69 Posted March 6, 2015 Share Posted March 6, 2015 Line your crank mark up and with no1 at TDC the cam gear marks should be at twelve o clock. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 6, 2015 Share Posted March 6, 2015 Epoxy'd and heat shrink the coils. Id be getting brand new coil packs, Whifbitz etc sell them at a good price. Misfire under load is a weak spark generally. Quote Link to comment Share on other sites More sharing options...
Guest pharmed Posted March 7, 2015 Share Posted March 7, 2015 £360 from wiffbits or supersparks from Australia/usa for 180 ish As per suggest I've done the following today - Checked the timing and tdc is at 12 o'clock so timing spot on and not slipped so no adjustment needed - Cleaned the connectors for the Cam shaft sensors. They were covered in oil! - Could not get to the crank sensor need to swing alternator out the way etc and ran out of time The engine management light now never comes on! But there is still a misfire under load. I'll try to fit the fcd and report back. Interestingly enough I've noticed a small misfire on startup (first minute or so) since gapping to 0.65mm Could this be because my gaps too small now? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 7, 2015 Share Posted March 7, 2015 The crank sensor connector is well away from the sensor itself, which is on a flying lead. It comes out of the loom that goes to the two VSV's by the front turbo, and is originally fastened to the drivers side inner wing, low down. The sensor just has an 18 inch or so long lead on it, then the connector itself. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.