misfire/ ignition breakdown

[BeRad]

quick run down on the engine

3rzfe plus the turbo
haltech ecu
running stock twin coil packs with internal ignitors.
9.0mm leads
stock spark plugs.

(the dyno shop has the haltech to run these coils/ignitor packs as dumb ignitors but if i change it to smart it seems to run smoother when i apply this change the engine almost stalls and then comes back up to idle and tends to run and idle better but still hits the 7psi breakdown that i talk about down lower)

my o2 guage is showing good a/f's so id assume this is not to blame.
a few weeks ago i got the car back from the dyno, and all was fine for almost a week, until now when sometimes it will mis every 10 seconds or so at idle, and then will rev fine until around 7psi of boost and then it will misfire again with a slight hickup along the way to 7psi. until i back off i cant push through breakdown. so i replaced the plugs, and leads and checked all the wiring. so all seems fine. but the problem is still there the only thing that i can think of is a coil pack is slowly dieing but i jst cant see how it revs from just above idle to 7psi without an issue but sit at idle and it will miss everynow and then and then hit a wall at 7psi (its not boost cut totally different to boost cut). although when i pull the spark plugs out all 4 are perfect if that leads anyone toward something that would be good


has anyone got any ideas or had this problem so i can solve it

thanks
brad

[TA22-3SGTE]

Try going into your ignition setup and changing the charge time , this may help .

Trevor

[Jorrs]

had similiar issues,
TPS on way out ? turning injectors of underload, and dying on idle.

[Granto]

do you have the option to do data logging?

it should tell you everything you need to know..

[BeRad]

yer spark time doesnt effect the problem at all.. tps yer not sure doesnt ussualy die on idle though and responds good when i calibrate it.

yer never thought about datalogging ill have a chop at that soon

any other ideas guys,

thanks
brad


just read a comment that the chuckster made in another thread, it goes like this

"yep - a twin-post coil can only create one strong spark and a weak one (for the cyl at the zorst stroke)."

would there be some way that its firing a weak spark when it should be the strong spark???? and how would i go about fixing this.....? would it be wiring or a setting in the ecu

[thechuckster]

Berad: measure the resistance & Inductance of the coil packs - that'll show you if the windings are breaking down. But as yours are integrated units, the only thing you'll be able to do is measure resistance across each post and from each post to ground... so maybe a factory manual is required to test the coils?

Do you know if the coil-pack igniters can do dwell control?

Are the coils getting very warm (assuming they're not mounted close to the engine). If they're getting warm, the dwell control is up the shit

Some data logs would be good

You might find (like me) that the missing was northing to do with tune - alt B post was touching engine mount so for every big spark there, the engine missed.

[BeRad]

the coils do warm up a little but they are bolted to the block in the factory position so hard to tell, what stuffs me is it wasnt working then i got it tuned and it worked for a week then went back to its old ways, i didnt even connect the laptop to the ecu to see what theyd done until it stuffed up when i saved there map so i had a copy. i ran a 43 second data log but have no way of getting it onto this comp as the ecu i used the burner is busted.

a quick few questions about toyota coils in general. does the trigger run off rising of falling edge, same with the coils/ignitors?. dwell i have set to 3.5ms, i assume there dum ignitors this is because if i have it on smart and set to 75% cycle the engine will run better, but if i turn it off it wont start again. and it still has the problem of hittin a 7psi wall , if i pull the intercooler pipe off so the engines running n/a the car will rev to redline without a hitch.

[BeRad]

finally got my timing light back off my mate, locked and checked the timing just to double check, the timing is spot on but im not suprised one of the coil packs is almost destroyed, the light wont even pick a signal up off lead 1 and picks up every 2nd spark from lead 4, pulled lead 4 off and its not even arcing to anything, plug it back in and the engine runs on 4 cylinders again but its so weak that id say the boost blows it out or just cant keep up. puleld lead 3 off and the spark is arcing almost 2 inchs haha, so time for a new coil pack i think

[thechuckster]

good to hear - saves eleventy-billion hours of testing different dwell settings because no-one wants to publish them

you going to get OEM replacement or dumb coils and run external igniters?

[BeRad]

might just get an oem one, i have the dual channel haltech ignitor sitting here but its not needed, i think richards more than proved the stock stuff is more than up to the task, if another one fails ill just get some dumb coils..


thanks for helping out.

[fixeruperer]

i take it you have already tested the resistance on everything.
how does your engine see the timing is it cam or crank angle sensor, does it use magnetic pickup.
you could have to much noise in the pickup
if its magnetic you mite have get rid of it and buy the hall affect sensor from haltech.
you mite get away with gettn that ignition wave converter from haltech wich turns your signal to a simple on/off sensor like the hall affect.

[cri_ag]

dude what model haltech? both myself and a good friend have had dramas with the tacho outputs on them, mine currently missfires as a result of having the tacho connected, dissconnect the tacho - no more missfire. i havent as yet found a soulution that works yet.

[BeRad]

hen, has dont many of writetups to make the haltech work properly with a tacho, find one of his theads...


it was definately the coil replaced it, and all was fine, the signal the sensor is sending is perfect nice and clean as i increase rpm's.

thanks