Friday, April 15, 2011 - 04:29 pm, by: Harley Jones(Dvjzz30)
ok guys ive recently been having this problem and both myself and my mechanic are at our wits end with it. so ill give the full details.
Car is running on a big single, was making 420rwhp for a while then i lunched my old 1j. so we built a new one, while i was at it i sourced a set of 440cc injectors and a few other bits and pieces. built a really strong 1j and stuck it in with the new 440cc injectors. drove it around for 2000ks to break in the new motor then took it back into the workshop to retune it for a bit more power.
we added an extra inline fuel pump to help things out and stuck a rrfpr on also. we Managed to squeeze 485 rwhp out of it without ignition timing adjustments and it was running great. When i picked it up i drove about 2kms and it just started cutting ignition for a few seconds. Initially under load or boost, but it got very bad very quick. to the point that I couldnt even pull out of an intersection without it cutting ignition and fuel.
It seemed to be related to throttle input (as soon as i gave it any throttle whatsover it would just cut spark) so we replaced the tps and still had exactly the same problem. since then we have done various testing on and off the dyno and replaced the following trying to find the cause of it
ignitor coils plugs (several times. tried gapped to .7,.6 and even .5...no difference) map sensor tps soarer ecu emanage ultimate crank angle sensor
The few times we have taken it on the road we have found the following
1. when its cold it runs great and makes more power than you could imagine with no problem 2. as it reaches operating temperature it starts cutting fuel and ignition as you see boost or excess load 3. as it gets warmer still it will start cutting fuel and ignition completely randomly, with any throttle input or even just idling it will cut fuel and spark and die. then it wont spark as you are trying to fire it up. 4. if you let it sit and cool down the symptoms will downgrade and it will become drivable again. 5. if you let it cool completely then it will run like a champ and make super power again until it starts to warm up.
on the dyno we have noted that there is no problem with fuel pressure when this is happening.
does anybody have any idea whatsoever as we are completely at a loss we are going to try new cam angle sensors on monday, but after that we dont know where to go.
Friday, April 15, 2011 - 06:48 pm, by: Daniel Clarke(Dieseltrain)
What about Cam angle sensors ? Compression test ? Temp sensors ?
Does it do the same with EMU removed ? Wiring issue related to ECU's ? You changed injectors , damage the ignition harness that runs accross the inlet manifold towards front of car ?
Also generall Earth points on car are ok ? Sounds like something electrical getting hot and failing much like an old ignition module .
Friday, April 15, 2011 - 08:29 pm, by: Harley Jones(Dvjzz30)
thanks for the replys guys.
James the emanage is definately jumpered correctly, It was running fine on the emanage with over 400hp for months on the old motor and for over 2000ks on the new motor before this problem popped up, I personally set all the jumpers on the new emanage I tested with and it did the same with that one too.
Daniel we are changing the cam angle sensors on monday and we are really hoping this is it. I havnt had a chance to run it with the emu removed. But it did it both before and after the emu was rewired and with 2 different emu units. but nothing was changed with the emu between when it was running fine and when it started playing up. It is something we will look at if the cam angle sensors dont sort it out though.
Re: temp sensors I know alot of people run their 1js without water temp sensors and dont have any issues like this. But we were thinking it could possibly be the air temp sensor playing up?
Earth points are all fine. Both me and my tuner have checked and double checked them all.
cihan its throwing no error codes whatsoever, that is the most aggrivating thing, the scan tool wont talk to the damn soarer, we are getting no error codes and the emanage cant tell us anything except that its not getting any injector or ignition input when cuts.
I guess on monday we will double check the cam timing while we are replacing the cam angle sensors and ill report back with whatever we find.
Thanks again for the time and the suggestions.
Cihan Aday Moderator Etuner.com.au New Website & Forum JZZ30
Saturday, April 16, 2011 - 07:34 am, by: Cihan Aday(Cihan)
James, it'll only become a problem when the ECU decides its out of range. I had a walk in freshly built 2J on the dyno a fortnight ago for run in tuning, intake cam gear hadn't been tightened, slipped to full advance. Powered by a powerFC had the following symptoms;
- Car ran fine post cold start, high idle + revving fine - Once warmed up ~70 degrees seemingly 'random' ignition and fuel cut under about 2000rpm where the idle circuit should be active. - Once it decides to cut, makes no difference if you go wide open throttle. - Rough AFR's / choppy under < 2000rpm or so.
According to the Toyota service manual, if there is no igniter synch output (IGF) the ECU will cut the engine after a few seconds. The problem in the Supra's case was the window where the IGF signal disappeared as the engine operated in the lower RPM region.
Mechanically if you advance the intake cam too far the engine will backfire at low revs with load. Also, it will loose synch and you'll have a mistimed spark which potentially translates to popping and other weird symptoms because these engines use a reluctor type crank and cam angle sensor. If the number of teeth between a trigger event and home event is incorrect for more than x events the OEM ecu cuts the engine.
Harley, i think you'll find the car will run just the same if you disconnect the intake temp sensor. Toyota ECU's revert to a maximum correction when you pull an intake temp sensor, or 02 sensor. I believe the difference is ~%10 fuel and 4-5 degrees ignition retard when the IAT signal is missing (easy way to get some extra fuel from the OEM computer and pull a few degree's with a pot BTW).
I would pull the #1 spark plug, send piston 1 to TDC, cams should be lined up straight with the crank as per TSM. Camgears in the middle of the adjustment window. If that is double OK - then scope the cam angle sensors (G1 & G2 ECU side) to see what is going on / whether the signal is clean from either sensor.
On another note - were the head valve seats redone in this build, and were the shims redone to suit? If the seats were cut and it was shimmed tight the valves could be unseated (never fully closed) when the engine warms up. But this won't necessary 'cut' the engine, it'll just idle funny, pop and misbehave as it gets hotter and hotter.
On that note, if engine was running for 2000kms its hard to see how it would be a mechanical problem. Lets hope its the cam angle sensors.
Sunday, April 17, 2011 - 01:27 am, by: David Ward(Djwtoyota)
James, I had a similar problem some time ago where the motor would warm up and then for no apparent reason and quite randomly die or miss. It only happened once warm, once cooled down again it was fine. Took ages to track down but ended up being a faulty MAP sensor. I know you've checked it and Cihan has offered his wealth of knowledge but for what it's worth that is what I eventually discovered because the ECU goes closed loop ( I think that is what it's called) once it reaches 66 C under that temp none of the inputs effect the ECU...like a choke mode. No harm in double checking perhaps? cheers David
Sunday, April 17, 2011 - 03:41 am, by: Harley Jones(Dvjzz30)
big thanks dave and once again cihan. I will update sometime in a few days after we have had a chance to try everything out and have some more information.
seems we have quite a list of things to look for again, the best thing we can possibly have when we were running out of ideas. thanks again guys I will let yas know how it pans out.
Monday, April 18, 2011 - 02:29 pm, by: Harley Jones(Dvjzz30)
ok guys i went over to the workshop and spent some time with it today..here is how I went...
I tried it without the cam angle sensors map sensor water temp sensor intake temp sensor O2 sensor TPS
I unplugged one, tested, plugged it back in and moved onto the next one.
All gave no change in the way it was running bar the tps, it just acted like you would expect it to act without the tps plugged in, then it died lol.
I checked the cam timing and the intake is spot on, the exhaust is a few deg out (but its been like that since day one, not the problem)
I couldnt get my hands on new cam angle sensors to test but they really look like a pita to change anyway. I also couldnt get to the knock sensor because I couldnt get the car in the air. Im half thinking about pulling the emanage and stock ecu out, wiring a haltech in and letting it tell me wtf is going on.
Monday, April 18, 2011 - 03:53 pm, by: Harley Jones(Dvjzz30)
the problem is exactly the same.
runs fine when cold, cuts ignition with load or boost when at operating temp, then cuts ignition with throttle input or randomly as it gets a little warmer under the hood after that.
ive made a couple of videos..ill upload them to youtube bit later and link
http://www.youtube.com/watch?v=veLmvGvFnjI just ignore the car on the dyno in the background at the end of the second vid. And yes the video and audio is in perfect sync....unfortunately...
I left it ideling for about 5 minutes after this was taken and it just died on idle, and refused to run for more than 10 seconds again until it cooled down.
Cihan Aday Moderator Etuner.com.au New Website & Forum JZZ30
Tuesday, May 03, 2011 - 11:24 pm, by: Harley Jones(Dvjzz30)
ok guys time for an update
cam angle sensors didnt fix it knock sensors didnt fix it water and air temp sensors didnt fix it Alternator has tested fine (so its not caused by wildly fluctuating voltages comming from it)...
we have tested every input for continuity beteen the sensors and the ecu..everything seems fine.
having replaced every sensor, the ecu, the emanage. The wiring and loom is fine...we are oficially at the end of our rope on this one. any last ideas before i part the car out and burn it?
Wednesday, May 04, 2011 - 07:57 pm, by: Sebastian Grant(Saabg)
Same thing happened to me in my old ea falcon. Used to run well for the first few minutes then it would lose half it's power. Turned out to be a dirty, dirty fuel filter. All the sediment would settle when the car was off so when I start it, it would run fine but after a while the sediment would block the filter again. You said you checked fuel pressure already but I thought I'd just throw it out there.
Dan McColl Goo Roo Victoria (The Nazi State) Active V8 and the Beast.
Wednesday, May 04, 2011 - 09:01 pm, by: Costa Tsimiklis(Driftshop)
Yep, that could do it - or damaged crank tooth setup.
Remove the front harmonic balancer to get a better view. The mount is on the oil pump.
To be honest it sounds like huge electrical wiring problem with an intermittent fault. I would go through and see if any wires are broken, corroded and check for resistance and continuity.
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