oldrx Posted August 17, 2009 Share Posted August 17, 2009 Ok so its not OS but hoping someone here might know what the problem with my black top 4age is (in a Carib wagon). It has a bad problem detonating but only on light throttle and even on decel it crackles a bit sometimes. Its only does it sometimes though. Just put in new plugs and new 02 sensor, running way better now but didnt fix detonation. Only run it on 98 gas. Only does it when warmed up. Thinking it might be as the filter is behind headlight with no airbox (on to do list). But shouldnt there be a intake air temp sensor that takes care of that shit? Any help appreciated. Nick Quote Link to comment Share on other sites More sharing options...
Hemi Posted August 17, 2009 Share Posted August 17, 2009 Ok so its not OS but hoping someone here might know what the problem with my black top 4age is (in a Carib wagon).It has a bad problem detonating but only on light throttle and even on decel it crackles a bit sometimes. Its only does it sometimes though. Just put in new plugs and new 02 sensor, running way better now but didnt fix detonation. Only run it on 98 gas. Only does it when warmed up. Thinking it might be as the filter is behind headlight with no airbox (on to do list). But shouldnt there be a intake air temp sensor that takes care of that shit? Any help appreciated. Nick crackcel on decel can be late timing. im prtty sure most efi engine cut fuel on decel anyhow?? , maybe your ecu is going into limp or open loop operation and overly enriching the mixture due to a faulty det sensor??? Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted August 17, 2009 Share Posted August 17, 2009 mine does similar things, Over on toyspeed there's a thread about things the blacktops do that are annoying like this. Some peoples problems are solved by replacing o2 sensor and knock sensor, others continue to have issues. I have been told by an autosparky with ALOT of 4a experience that the factory ecu itself is to blame. Unfortunatly these fixes aren't cheap Quote Link to comment Share on other sites More sharing options...
David Posted August 17, 2009 Share Posted August 17, 2009 How many Km's has it done. My mate had a 4age doing simila acts and we changed every thing and got no ware. With some advise it turned out it was burning a wee bit of oil. turns out if you mix a small bit of oil with petrol it brings it's octain rating down so tends to make your motor pink. It's worth wile checking all the other electrical parts first as they are cheaper than an unnecessary motor rebuild. But hay if you filling it with oil every other week it could be the answer. Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted August 17, 2009 Share Posted August 17, 2009 That could be whats going wrong with mine! It uses a litre of oil every couple 1000 k's. How to fixington? Quote Link to comment Share on other sites More sharing options...
oldrx Posted August 17, 2009 Author Share Posted August 17, 2009 Thanks for quick replies. Will have to look into knock sensor. Where is it? Forgot to mention the speed sensor is probably not connected as the engine light comes on and the codes were 02 sensor (fixed now) and speed sensor. I am under the impression that a non functional speed sensor would only drop the rpm cut point though so prob not that... maybe? Oh and it has been running very rich for some time before i got it judging by lots of black sooty shit in exhaust pipe. It does use a bit of oil. And no doubt had a hard life. But only about half a litre a month at the most. Quote Link to comment Share on other sites More sharing options...
forced Posted August 19, 2009 Share Posted August 19, 2009 You should have reset the ECU after changing the o2 sensor. The faulty o2 sensor would have made it run too rich. Running too rich will accelerate wear which accelerates the consumption of oil. Burning oil reduces the octane rating of the fuel and might contribute towards detonation. Detonation at light throttle is always caused by too much timing.It can't detobnate whist decelerating but can backfire, caused by running too rich. Of course it might not be detonating at all, you might just be diagnosing it wrong. The only thing that ever goes wrong with Toyota ECUs is identical to Mitsi ECUs.....capacitors leaking. Steve Quote Link to comment Share on other sites More sharing options...
mikuni Posted August 19, 2009 Share Posted August 19, 2009 A little bit un helpful but the user on here Mike-E was telling me ages ago that these ecu's fuck out regularly and are often the cause for very cunty and hard to find problems. The fault is leaky caps in the ecu and these can be replaced I believe - heaps cheaper than buying a new or trying to try down a second hand ecu. It may be worth a pm to him or as mentioned above, have a hunt around on toyspeed for similar issues. Popping the lid on your ecu may also help to determine the problem. Quote Link to comment Share on other sites More sharing options...
Truenotch Posted August 20, 2009 Share Posted August 20, 2009 That could be whats going wrong with mine!It uses a litre of oil every couple 1000 k's. How to fixington? Got any blowby? ... could be a worry if you do. Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted August 20, 2009 Share Posted August 20, 2009 Hrm dunno. TBH if it goes bang it's been a good cheap car. Quote Link to comment Share on other sites More sharing options...
Mr Revhead Posted August 22, 2009 Share Posted August 22, 2009 try an oil catch can to remove oil fumes, worked awesome on my 101. be sure to take feeds from both pipes from the rocker cover. a few different ways to do it, with each having slightly different results. no need to rest ecu when replacing knock sensor, the ecu doesn't store that fault, replacing the knock sensor instantly cures that issue. be a sad sad world if your ecu was that slow to react dead knock sensors throws ECL, code 52. The leaky caps is mainly a 101 problem i think, will cause arse running and stalling with no fault codes. among other things. Also check timing, should be set with ecu in diag mode, (bridge two terminals, e1 and te1 iirc) blacktops are petty border line on out fuels with pre ignition Quote Link to comment Share on other sites More sharing options...
oldrx Posted August 23, 2009 Author Share Posted August 23, 2009 Cheers, I reset ecu, running a bit better, less frequent detonation. I think on decel it might actually be little backfires. Going to make some sort of airbox and insulate intake pipe coz it gets hot as fuck - put my hand on it when checking oil at servo. Can anyone reccomend good stuff to insulate intake pipe? Quote Link to comment Share on other sites More sharing options...
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