Odd miss

[Guest]

Not plugs or gap.

[boon]

 evowrx said:

Rewired cop wiring to ecu seems a lot better. Before it had a massive stumble around 2.5-2.6k now its clean. It starts to miss as it gets hot once its hot itll miss noticeably. What would cause that? Faulty coil?

cough *gasket* cough cough cough.

[Guest]

Which one? Would have to be between tb and heads.

[boon]

Actually, dumb question... have you tried logging your ECT?

If it's flaking out the ECU will really rapidly switch between cold start fueling and hot fueling and make it run a bit ****. I know with a standard ECU the ECT sensor sucking causes all sorts of issues.

[Guest]

Yep its allgood first thing that came to mind.

[Guest]

Definitely fine when cold only misses when hot now. Starts and gets gradually worse as it gets hotter. If it had a vac leak wouldnt it show on map trace?

[hijacka]

Change out the plugs for the right ones, worth a try.. Don't knock it till you tried it lol

[Guest]

Have done twice and from 6 to 7 all burning fine every time. The plugs arent off the shelf like ej20 ones either no one stocks anything cooler than the stock 6.

[hijacka]

i've used supercheap degreaser in a can to i.d air leaks with great success.. get it idling and warmed to where problems seem to occur and spray around areas of concern plastics manifold gasket areas, injectors etc. if theres a leak then idle with fluctuate when you spray in that area.

[Guest]

Tried that but i use ether way more sensitive.

[hijacka]

 evowrx said:

Tried that but i use ether way more sensitive.

Hmmm Just don't breath it in very dangerous.. a $2.50 can of degreaser is alot cheaper than say $15 engine start or why, Don't get me wrong i've used it and found leaks with it but because the degreaser soaks the area its more likely to enter the intake through the areas of concern rather than a atomized spray like engine start that also vaporizes quickly

[Guest]

I used to use brakeclean but ether handier sits beside the car on the lawnmower. Tuner used odd fluid one time left spots all over mani mightve been coz it dried on hot ot something tho. Dont use degreaser just brakeclean then a real toxic pink product allkleen to clean anything really filthy but its nasty nasty.

[Guest]

Replaced all gaskets south of tb and blocked all vac lines didnt fix it. Hopefully get my hands on a set of coils tomorrow and swap them out see if thats the issue.

[Guest]

Edited May 9, 2015 by evowrx

[Rosssub]

Did you try swapping the coils out?

Reading through most Link wire in documentation, when using coils with built in ignitors. They want an earthed 1-2 UF suppressor installed on the 12v feed to the coils. A symptom of no suppressor is misfires:

http://www.linkecu.com/support/documentation/technical-drawings/I14

Covered under the ignition section in this Link G4 install PDF:

http://www.linkecu.com/support/documentation/g4plus-engine-management-documentation/g4plus-wiring-installation-manual/view

Same deal for the older G3 wire in, but no mention of suppressors with the G4 plugins.

They also mention dropping the spark plug gap down to as little as 0.5mm helps with electrical feedback issues.

[Guest]

Im running a bit over .6. I have tried swapping back to v6 pack and leads before i started the fault finding mission and made no difference. Cant do that anymore as factory loom plug is redundant now. Got a mate digging in his rally car spares for late cop ones.

Where do i find said suppressor? Ill try almost anything at this stage. The v5 plug in g4 does expect a wasted pack not wasted cop too so wouldnt say anything in manual.

[Rosssub]

Not sure where to get the 1-2 UF suppressor from. But an old distributors condenser/capacitor will do the same thing (covered on page 78 ignition wiring section 11.2.3 of the G4 install).

Edited May 10, 2015 by Rosssub

[Guest]

Thought so i know where plenty of those are. Will give it a crack and let you know. Thanks.

[Guest]

Im running the avcs/cam stuff off same positive wire at ecu will it matter if theyre suppressed?

[Rosssub]

Could cause issues.

The coils 12v feed should be separate from the ECU feed, switched by an ignition or main relay. Be better to use the original 12v feed for the V5/6 coil pack.

[Guest]

So I have a 1uf capacitor will that do the same thing?

[Rosssub]

Should do, it will be within the Link documentation specs.

[Guest]

 Rosssub said:

Could cause issues.

The coils 12v feed should be separate from the ECU feed, switched by an ignition or main relay. Be better to use the original 12v feed for the V5/6 coil pack.

G12 shows the cam sensors and coils sharing +12v feed but nothing about a suppressor or where it would fit...

[Guest]

 evowrx said:

G12 shows the cam sensors and coils sharing +12v feed but nothing about a suppressor or where it would fit...

Actually it does in the notes. One per coil.

[Rosssub]

 evowrx said:

Actually it does in the notes. One per coil.

One suppressor per bank on the 12v coil feed:

http://www.linkecu.com/support/documentation/technical-drawings/G12%20-%20Subaru%20EJ20-25%20Dual-Quad%20AVCS%20Wiring.pdf

Diagram G12 refers to diagram G03 for the coils +12v feed. Diagram G03 is for the older LEM G3:

http://www.linkecu.com/support/documentation/technical-drawings/G03

Link G4+ documentation shows coils power from a separate relay, page 24 diagram 9.1:

http://www.linkecu.com/support/documentation/g4plus-engine-management-documentation/g4plus-wiring-installation-manual/view

Edited May 16, 2015 by Rosssub