Coilpacks

[John Dixon]

Anyone know if there are aftermarket coilpacks available or how much the nissan ones are new?Having a problem with missfires on 3 cyls and think it may just be the (now 15yr old) coilpacks struggling to spark across the higher compression.Going to try to close the plug gaps down a bit and maybe increse the coil charge time in the ECU and see if that helps. Its SO annoying Faliling all that I'll rip the system off and replace it with some ford packs or something if the nissan ones are too much $$$

[darinz]

We thought this was the problem with mine when we first started tuning it. Smaller gaps and replaced coils didn't change a thing. Replacing factory ignitors etc with CDI ignition and all sorted!

[Bart]

Depending on the model of the VH41/45 the ignitors could be the same as on the SR20. So if you have probs getting ignitors for your VH you can search around for a more common SR ignitor as i have discovered. (just make sure the connectors are the same as they vary)

[John Dixon]

Cheers for the replies.Think the ignitors are OK as with the coils pulled out I get a spark across all the plugs, just guess it's not strong enough. Will have a fiddle in the next few days.Cheers

[Q45tech]

Coils are robust, usually the problem is with the extension insulation from coil to plug, just as it was in old days with plug wires.

Using an oscilloscope to view the input and output waveform is standard diagnostic proceedure..................as it was in the 1960s.

http://www.picoauto.com/wavefo...ndaryh ... ri....html

[John Dixon]

Are the insulators available seperately? I was really talking of the combined coil/insulator when I was referring to coilpacks.

[XJared]

The OE Nissan coils work really well if you add a CDI box. I'm a big fan of the M&W boxes, not cheap, but high quality and last a long time.

[John Dixon]

Cheers for the advice, will look into CDI and see what I can get.

[maxnix]

Coilpacks are robust and shouldn't be the source of any problems barring individual failures. I would check the igniters, but you said it is not one bank or the other but a specific cylinders.

You are using NGK PFRG5?

[John Dixon]

Coilpacks are robust and shouldn't be the source of any problems barring individual failures. I would check the igniters, but you said it is not one bank or the other but a specific cylinders.

You are using NGK PFRG5?

I've swapped the ignitors already to see if the fault followed them, it didn't.I'm using NGK BKR7EIX-11 closed up to 0.8mm at the minute. With higher compression ratio and rev limit will need a colder plug than stock.

[darinz]

I'm running NGK BKR6E-11 with factory coils (original 1989 ones), Autronic CDI and Avgas. Also gaps are 1mm.Do you need to be that cold on you plugs and if you are closing gaps, then shouldn't you be thinking hard about a CDI?

[Carl H]

7's are pretty effin cold for an na engine...i run bcpr7es plugs gapped to .8mm on my rb20 which i cram 22psi+ into out of a gt30r.the dynamic cr is much higher on that engine than on your high comp engine.i'd honestly see if you could run 6's and be ok, nissan specifies 2 cold plugs over the standard 5's which are the 6 and 7 heatrange plugs but you would have to be in the desert in the middle of the sahara to need the 7 plugs imho.as far as your spark problem is going, im sure you did the wiring right but make sure it has a good dedicated 12v feed to the coils...tapping into anything else will dramatically decrease spark potential.also it has been my experience that with nissan coils if the afrs are low 11's, high 10's no matter what you do to it the coils simply cannot blow thru a mixture that rich; perhaps in this case a spark amp would help but a good tune would negate the need.there are LOADS of rb based engines running around making silly power on standard ignitors and coils so i would think that your engine would be ok with standard gear as well.

[John Dixon]

Darinz, yes, I am thinking of CDI but it's an expensive option and if I can get the standard stuff working first I'll try that.I'm using 7's based not just on CR but revs too. 9k is going to put a lot more heat cycles into the plugs than that standard rev limit too (7k from memory?). Either way once it's running I can check the plug heat range. I have just got some PFR6B to try but it's finding the time that's the problem at the minute!Won't be running anywhere near 10-11AFR on this, besides, the problem is even shoing up on idle at the minute. 12v feed is a direct feed to just the coils from the original 300zx coil relay on quite heavy gauge cable so should be no problem with that.Cheers for the replies!

There's a vis of it running with the full exhaust on here http://www.youtube.com/watch?v=xwE1LD4XrO0You can see at the start when I pull two of the injector plugs off there is just NO difference at all. Can hear the two exhaust modes too, bypassed and silenced but sounds a bit rubbish as only on 5 cyls

[maxnix]

I'm using NGK BKR7EIX-11 closed up to 0.8mm at the minute. With higher compression ratio and rev limit will need a colder plug than stock.

Wrong plug!

NGK PFRG6-11

In soggy olde England, 5 range should be fine.

[Johnny Rocket]

Coils are robust, usually the problem is with the extension insulation from coil to plug, just as it was in old days with plug wires.

Using an oscilloscope to view the input and output waveform is standard diagnostic proceedure..................as it was in the 1960s.

http://www.picoauto.com/wavefo...ndaryh ... ri....html

What do you call robust?.........millijoules are what?

I would like to hear a figure on this since I know what the modern day chevys are over 100 millijoules

My guess is they are weak.....20 year old technology in a coil pack...just a guess.probably in the 20 millijoule range?

[Johnny Rocket]

Change to modern day coil packs....with higher output...

My bet is the stock Vh stuff is around 20 Millijoules and the new stuff is over a 100

[John Dixon]

I got the problem sorted out, thanks.

[EMK]

What was the solution? So as to save those of use who have yet to solve this problem yet unfortunately run into it.

[John Dixon]

See other thread here: zer...-help

Unlikely to effect anyone else as it was an ECU firmware issue.

[maxnix]

I would like to hear a figure on this since I know what the modern day chevys are over 100 millijoules

My guess is they are weak.....20 year old technology in a coil pack...just a guess.probably in the 20 millijoule range?

There was this guy named Nikolas Tesla. Might want to read about him.

The technoclogy is over a century old and hasn't changed at all in principle.

[Johnny Rocket]

We still dont have a spec......the new Ford mod engine has crappy coils compared to the GM coil....

Just wondered what we are caling Robust..that word is used to loosely for my thoughts

There is a thing called a smart coil and a dumb coil...might want to read about that before we get into hero worship

[shytdoode]

kts ftw