Rb20de strange issue not your usual coil pack misfire…

[RBZRYUM]

Greetings to all you rb cats out there, I’ve run into a slight issue with my rb20de cefiro and am having a fun time trying to diagnose what’s wrong with it 😂 , have read up quite a few forums already posted an I can’t seem to find any close to the issues I’m experiencing.

so basically what’s happening is the car starts takes a few goes when it’s cold yea not ideal but once it fires up it runs relatively smooth firing on all 6, idles pretty good really , once it’s warmed up idles an drives ok  , il give it a good bit of throttle an push it through the rev range an it does so nicely…but as soon as I hit around 6500rpm  it’s farts an shits an sounds like it runs 4 cylinders even once I’ve backed off an just trying to let it idle , the misfires will continue for maybe 30sec to 1minute max then the car will go back to idling smoothly an running on all 6 again. 
 Engine is stock apart from aftermarket coil packs and a Walbro fuel pump.

I have replaced the cas, coil packs, fuel pump , and spark plugs so far.

any ideas would be much appreciated. 

cheers

[Murray_Calavera]

What type of coil packs are you using now and are they brand new?

[RBZRYUM]

1 hour ago, Murray_Calavera said:

What type of coil packs are you using now and are they brand new?

Have 2 sets at my disposal an were both relatively new, have checked them over with a multimeter aswell. They are Osaka imports an on set are savage coils

[RBZRYUM]

Just now, RBZRYUM said:

Have 2 sets at my disposal an were both relatively new, have checked them over with a multimeter aswell. They are Osaka imports an on set are savage coils

Is it possible the igniter is getting heat soaked an failing?? 

[Murray_Calavera]

6 minutes ago, RBZRYUM said:

Is it possible the igniter is getting heat soaked an failing?? 

My money is still on faulty coil packs.

If I was in your shoes, I'd throw in a set of brand new coil packs. Either Splitfire or OEM.

 

[Duncan]

Yes that is possible, I've had an ignitor fail when hot and cause a missfire. May not be easy to find a good one to swap in though

[RBZRYUM]

It’s 100% not coil pack issue , the set has been in a another vehicle that’s been more modified an it ran fine no issues?? Could I maybe have a toast hydraulic lifter??

[Murray_Calavera]

42 minutes ago, RBZRYUM said:

It’s 100% not coil pack issue , the set has been in a another vehicle that’s been more modified an it ran fine no issues?? Could I maybe have a toast hydraulic lifter??

Any chance you can borrow an ignitor from a running car? 

[RBZRYUM]

I have yet to source another igniter an one is relatively hard to find atm, have reached out to the boys but all there igniters seem to have different plug to mine , is there anyway to test my igniter?

[GTSBoy]

25 minutes ago, RBZRYUM said:

is there anyway to test my igniter?

Not really. It's just a box with 6 transistors in it. The usual failure mode is that they refuse to switch the coils when they get too hot, which is probably a solder joint problem, but could be in the silicon. Swaptronics is usually the only way to demonstrate good/bad.

A million years ago I made a set of spacers (out of some ~6mm stainless tube and some longer bolts to lift mine up off the coil cover and try to improve airflow underneath. It did a pretty good job of eliminating the occasional heat soak issue I was having with mine. The ultimate solution was to replace the RB20 with a bigger engine.

If you are having a real problem with the igniter, the correct solution these days is to bin it and the dumb coils and upgrade to a pencil coil kit (R35, Audi, etc). Do the necessary rewiring (trivial) and boost off* into the sunset.

*Sorry, wheeze off asthmatically into the sunset.

[RBZRYUM]

Yea I’m currently building a forged 25 for it but love to just drive it around over the summer break , don’t really wana spend money on the 20 haha as you could imagine