Ignition breakup above 5500rpms

[dok33]

So I have a 2jzge NA-T but I'm running it on the 7MGTE ECU (hence posting in this section) so troubleshooting ignition should be the same. I'm running 12psi with a T70 right now and am having issues with ignition breakup from 5500rpms up.

I regapped the plugs to .022 and it helped some but I'm still having issues. Seems to get worse as the car gets warmer as well. Guessing I shouldn't go any narrower on the gap?

I've got a good set of coils on there with a good coil harness (after going through a couple of sets and picking the best parts), but the plug wires are off my old 7M so my next step is to put some new ones on.

The CPS wiring is also a little fubared, I siliconed the wires to keep them from shorting to each other but I think I'm also going to order the clips with pigtails from toyota and redo the wiring/plug as well. I also have additional grounds running from the coil pack bracket and igniter for good measure.

Sound like I'm on the right track? Any other ideas?

 

[Poodles]

As someone else had this issue, and I know your coils are mounted on the firewall, make sure that the wires are seperated properly.

You could always go to the IS300 coils...

 

[dok33]

Not sure what you mean, separate how?

 

[Poodles]

With the little plastic wire seperators. If they're just bundled together they may crossfire, and it usually happens at torque peak.


Paging IJ...

 

[dok33]

Ahh, yea, the way they're run they do kind of sit on top of each other, didn't realize that would cause issues. Might have to dig some of those up, don't think I've got any laying around...

 

[Poodles]

cheap as hell at any autoparts store, but I still think the IS300 coils would look better

 

[IJ.]

Wires shouldn't run side by side too closely or you risk a crossfire, but it may just be a case of sparkblowout if it's starting around 5200rpm.

Get the seperators for sure and see if it improves, you can't knock the gaps down anymore than they are without deforming the ground electrode and possibly weakening it.

 

[Who]

I thought the cable separators were used to tidy up the engine bay and prevent the cables from touching hot surfaces. I never knew current could go across two layers of insulation. Lesson learned.

 

[dok33]

IS coils would be nice but I've spent enough on the car in the past few months:aigo: No good import junkyards around me either...

I'll try new wires and the separators and see what happens, really wanting to boost more than 12psi to see if I can get it to spin through 3rd :evil2:

 

[IJ.]

Back in the "old days" we'd often take a car for a test spin around the block after an engine change without putting the hood back on
(most time no exhaust yet as well)

At night you'd see a spider web of blue over the distributor and leads, plug wires have improved a lot but you can still get the occasional crossfire, if leads need to cross each other it's best they do it at 90 degrees to each other.

So yes the stock seperators are there for a reason other than making the wires look pretty

 

[Poodles]

Not to mention if the leads get dirty.

A horrible prank we used to pull is to use a pencil and write all over someone's leads :evil2:

 

[IJ.]

^ Carbon track, we used to do this inside distributor caps :evil2:

 

[Poodles]

On that note...

[Poodles] 4:11 pm: bahhahah, IJ used to do the carbon track inside distributor caps LOL
[] 4:12 pm: yes i saw that.. funny
[] 4:12 pm:
[Poodles] 4:12 pm: that could cause some serious shit LOL
[] 4:12 pm: yes, and all while hidden!
[] 4:12 pm: lol
[Poodles] 4:12 pm: man, I'm gonna get a job at a poarts store and do it to a bunch of caps on the shelf
[] 4:12 pm: lmfao
[Poodles] 4:13 pm: just to see the faces of people coming back
[] 4:13 pm: indeed
[Poodles] 4:13 pm: or even worse have em do it in the parking lot and hear BANG!
[] 4:13 pm: not sure why this does not work! i just bought it
[Poodles] 4:15 pm: problem is that I couldn't keep a straight face
[] 4:15 pm: neither would i

But anyway, see if the seperators help, if not, it might be something else...

 

[Zumtizzle]

^LOL! @ you two.

 

[IJ.]

LOL pure evil
(works on rotor buttons but it will barely run at least on the cap it's just a bad miss)

 

[dok33]

Put some fresh plugs in and did the wire separators. Was stoked at first, all the way to the rev limiter without breakup! Then as the car got hotter it started to break up some, definitely not as bad as before. Tested my coils, ~1ohm across the terminals on the ones on the car and the other 2 sets I have. TSRM says ~0.5ohms, but it seems weird that all of mine read 1.

Any other ideas? Wanted to hit the track this weekend, debating on picking up a new set of wires at the parts store since I can get 'em in a day or so as opposed to having to wait a week or so for the IS coils since nowhere around here has 'em. Seems silly to spend $60 on wires though if I'm just ogoin to upgrade anyways...

 

[figgie]

Tested my coils, ~1ohm across the terminals on the ones on the car and the other 2 sets I have. TSRM says ~0.5ohms, but it seems weird that all of mine read 1.

Not weird actually. Most ohm meters will have an exceptional hard time getting a good sub 1 ohm resistance reading. Only the high end stuff does.

Now with that said, How are the 7M-GTE coils? No cracks or anything of that nature?

 

[dok33]

It's a $3 HF multimeter so that probably explains it :biglaugh:

Coils are in good shape, picked them up from Tubbie after finding cracks on the bottom of both sets I had. Also have a good coil harness on there (old one had some frayed wires).

Hopefully the new plug wires will make a difference, the ones on there are of unknown mileage but looked ok (highly precise measurement lol). Every little change is improving things so I think I'm gettin' closer. I had to break the seal at the boot to push the plug side connector down some to fit the 2jz galley cover and clip on, I think I'll shoot some silicone or something back in there on the new ones to make sure there's a good seal.

Seems like the 7M coils should be sufficient for my current power level from what I've seen, hopefully I can get this cleared up and save the IS300 coil swap for later on down the road...

 

[dok33]

Plug wires seem to have fixed the breakup! 15psi is insane, it'll break the back tires loose in 3rd at 70 on some road surfaces :love: 18psi here I come :naughty:

It's still running pretty lean at idle/cruise (17-19:1), probably due to the 680s and E85 (720s would have been a better fit but I got the 680s cheap) and I'm getting some surging at low throttle. I've got the base FP at 45psi with the vac line off, any more pressure doesn't richen the idle mixture anymore and I don't really want to run more than that anyways. Think I may try adjusting the low (0%?) throttle settings on the SAFC to try and richen it up a little. Prolly post up in the piggyback forum...