terryep91 Posted March 21, 2023 Report Share Posted March 21, 2023 hi Adam, Need your expertise please. I'm also experiencing random trigger misses on my 1997 Toyota Starlet, EP91 with 4efte engine. It doesn't seem to do it while the engine is cold and engine temp is under 80 degrees. I've attached my tune, log and trigger scope. Hope you can give pointers on what might be causing these random misses. thanks TriggerScopeLog.llgx PC Datalog - 2023-03-16 5;20;50 pm.llgx Current Tune.pclx Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 21, 2023 Report Share Posted March 21, 2023 What RPM was that trigger scope captured at? In your log the two occurrences of trigger errors both happened at idle, it that a common scenario or can they occur at any time? Quote Link to comment Share on other sites More sharing options...
terryep91 Posted March 21, 2023 Report Share Posted March 21, 2023 Trigger captured during cranking, please advise how or when it should be captured. The trigger errors can happen at at time. Idling at the lights, cruising at 50-60km/hr and on the motorway between 100-110km/hr. During idle, i can almost feel that it will happen when the rpm jiggles at 1000, engine feels a little rough then it would briefly cut off. It would cause a big jerk when moving the car from idle. Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 22, 2023 Report Share Posted March 22, 2023 Its going to be a tough one to find I think, the scope you captured when cranking looks perfectly fine. The Trig 1 signal disappears in your log when the trigger error occurs so I thought it may intermittently not quite cross the threshold when a fan is turned on or something, but if that scope was done during cranking I would say you have lots of voltage margin when running. Can you do another scope capture at idle and maybe one at 2000RPM. Is there any chance you could get a capture when an error occurred or is it too unpredictable? Quote Link to comment Share on other sites More sharing options...
terryep91 Posted March 23, 2023 Report Share Posted March 23, 2023 Hi Adam, Attached are the two scope captures at idle and and 2000rpm It's too intermittent to capture a scope when the trigger misses happens. I've also attached the log of today's drive. appreciate your help TriggerScopeLog 2000rpm.llgx TriggerScopeLog at idle.llgx PC Datalog - 2023-03-23 5;22;08 pm.zip Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 24, 2023 Report Share Posted March 24, 2023 I dont see any real good clues yet. Those 2 trigger scopes above are exactly the same file just named differently though, so another 1 or two of those would be good. The only thing so far that is not as good as I like is the G1 edge is not well-centred between the NE edges. Usually the Toyota distributors are quite good, you have 30deg between each NE tooth and the G1 is usually sitting right in the middle - so your cam edge is about 15 deg in either direction away from the nearest crank edge. In your scopes however it is about 23-4deg away in one direction and only 6-7deg away in the other. I would still think that should be enough wiggle room, but its closer than I normally like to run. Is there any adjustment of the G1 sensor in relation to the NE sensor in these distributors? Since I have never seen inside a 4AFE dizzy, can you explain how the two sensors are wired internally - do both ground wires join together somewhere and come out on a single pin like the earlier 4AG etc? Or do all 4 sensor wires come out separately? If they are separate grounds it could potentially be the NE is wired incorrect polarity as it is hard to tell with this type of trigger wheel. This would cause the falling edge to move and potentially cross over G1. Quote Link to comment Share on other sites More sharing options...
terryep91 Posted March 27, 2023 Report Share Posted March 27, 2023 hi Adam, My apologies on the mix up on files. I've recaptured them for you. I've attempted to capture on when the trigger miss happens but quite hard. Am waiting to hear back regarding the wiring of the G1 and NE sensors. thanks TriggerScopeLog close.llgx TriggerScopeLog at idle.llgx TriggerScopeLog 2000rpm.llgx Quote Link to comment Share on other sites More sharing options...
terryep91 Posted June 30, 2023 Report Share Posted June 30, 2023 Hi Adam, It's been a while and am still chasing the misfire. I've since done a few things and noticed a pattern before it misses. This is more frequent during idle, where it revs up a little then misses. I've changed from standard plugs to iridium heat 7 plugs and noticed the misfire is more predictable. The last miss on the log, the engine died. What are the ingredients to checking idling apart from Idle Speed control? appreciate your help. Quote Link to comment Share on other sites More sharing options...
Adamw Posted June 30, 2023 Report Share Posted June 30, 2023 Can you share the log file that you have used for the picture above. The misfire is still a trigger error. Can you try turning off idle ignition control, possibly you are commanding too much advance or retard for the rotor phasing. Quote Link to comment Share on other sites More sharing options...
terryep91 Posted July 2, 2023 Report Share Posted July 2, 2023 sure, attached PC Datalog - 2023-06-23 2;00;37 pm.zip Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 2, 2023 Report Share Posted July 2, 2023 It certainly gives me the impression of a rotor phasing issue as the error happens wihen you are at the most retarded ignition angle. So does turning off idle ign fix it? Quote Link to comment Share on other sites More sharing options...
terryep91 Posted July 3, 2023 Report Share Posted July 3, 2023 Sorry Adam, Rookie status is rookie i am, do you mind telling me where that setting might be please. Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 3, 2023 Report Share Posted July 3, 2023 terryep91 1 Quote Link to comment Share on other sites More sharing options...
terryep91 Posted July 9, 2023 Report Share Posted July 9, 2023 Thanks Adam, Idle Ignition Control is turned off, that rev up and miss isn't happening like before. The car has been driving beautifully for a couple of days. There is still a random miss but not as frequent as before. Your suggestion has definitely made an improvement, from a couple of misses in every drive to one in a couple of drives. Are there any other areas i can potential check and make improvements? Appreciate all your help. Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 10, 2023 Report Share Posted July 10, 2023 I suspect your remaining issue probably isnt related to the same rotor phasing issue as your ignition timing should see much less movement with idle ign control turned off. It would pay to check rotor phasing however just to confirm the distributor is posititioned somewhere close to ideal. Check what crank angle the rotor tip corner just reaches the post in the dist cap and also the crank angle that the rotor tip leaves the post. These angles are the max and min advance your distributor is capable of supporting. Note you can usually rotate the distributor if you need to move the range, but you cant make the range bigger. Quote Link to comment Share on other sites More sharing options...
terryep91 Posted July 18, 2023 Report Share Posted July 18, 2023 Hi Adam, i got an old distributor cap and drill holes to see the node and rotor. I rotated the crankshaft wheel to 10 degrees BTDC, the rotor tab was somewhere in the the middle of the 1st node on the cap. I loosen the distributor and twisted it until the tail end of the rotor tab was over the node, very close to the diagram above. Car drives ok, idles quite stable as well, i haven't noticed a miss fire yet, fingers crossing here. However i noticed it's harder to startup, Do i need to get the engine re timed with the ECU? I've also captured a trigger scope for your assessment, captured while engine is running. Many Many Thanks This is the current ignition setup TriggerScopeLog after rotor adjust.llgx Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 18, 2023 Report Share Posted July 18, 2023 Yes you will need to set the base timing if you have moved the distributor. Quote Link to comment Share on other sites More sharing options...
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