Worsening Misfire

[GH05T]

Ok so I purchased my new 89 rb20det r32 gtst earlier this week from a member.

The modifications are as follows (engine wise)

Roughly 210rwkw (apparently)

Running about 1bar boost

Trust td05 turbo

Bosch 044 fuel pump

Gtr injectors

Nistune

3" exhaust with screamer pipe

Z32 afm

HKS pod filter

Greedy intercooler

Manual boost controller

Apparently it's tunes for the set up

Apparently the coil packs are new

Running it on 98 BP ultimate, not sure but it seemed to worsen In 30 mins on caltex 98?

It did misfire on high boost but now on the way home it couldn't make any boost without cutting out.

It was hot today but it's not the first time to cut boost at random times

I know it can run on full boost and be happy because it did this morning?

Any help greatly appreciated.

Also if u have a good place for workshop/ tuning north of the CBD let me know

Glyn.

Edited December 24, 2011 by GH05T

[DVS JEZ]

What coilpacks does it have? What spark plugs.

[Matty Sherlock]

Go over every single grounding point on the car too, Can't hurt

[GTSBoy]

Igniter pack might not like getting hot. Get a can of freeze spray to test that one out (ie spray it when it starts missing and see if it comes good). Freeze spray can be a good test for the coils too, just in case they're not as great as they could be (even if new).

[GH05T]

Just for reference ran it just the round the block, ran better but still can't boost up properly with out throwing me forward with a decent missfire

[GH05T]

Not sure what the coilpacks are or really how old they are, same deal with spark plugs ATM,

What's the best value coilpacks for the job and who do I speak to about them

Also will do my plugs obviously, Do I gap at 8mm?

[Chris-06R]

Check your spark plugs (may as well replace them with new coppers - enough effort just to get to them on the RB20) - Gap them to .8mm or buy the right ones pre-gapped.

Try adjusting your boost back down and seeing if it still does it - could possibly be blowing out the spark which is coilpacks and spark plugs might fix.

Could also be fuel supply related too...

[Moodles2]

Check if it actually does have a tune, just because it's Nistune'd it could just be running a straight unmodified basemap.

[kitto]

Is it only miss-firing when the engine is hot? Or does it happen when its cold aswell?

It could be a range of things. I would start with;

- New BCPR6ES Plugs, i used them in my RB20 with 210kW on BP98 no problems at all, Some people with argue another plug, But this plug is the common copper plug to use in an RB. If it has Iridiums, throw them out and put coppers back in. Once again people will argue they are really good and i'm sure they are, but myself and a lot of other people have had nothing but issues with them.

- Clean your AFM with contact cleaner thoroughly

- Check all grounds as said earlier

- I'd change/clean your air filter and replace your fuel filter

- Remove your coil packs, remove the rubber boots and look for any corrosion or wearing on the graphite electrodes, maybe give them a quick sand to clean them up

If your still having the miss fire after you've done that, look at in order;

- Trying another ignitor

- Trying another CAS

- Your injectors may be clogged and could possibly be causing a miss, before changing them, i'd at least run a fuel system cleaner through them. Its possible, but before this i'd be looking at the tune.

If your suspicious of the tune, get Decs at Garage 7 to take a look at the tune for you.

[SargeRX8]

I'd use the 7 heat range. For an Rb20 you are making some power which means your temps will be on the higher side so a colder plug is better. Ive ran BCPR7ES in both my cars all day every day, Rb25 with 230rwkw and another rb25 with 250rwkw. The misfire could be one of the many reasons others have said. Spark plugs, coil packs, igniter. The tune will not affect the spark plugs. Your spark is being blown out because the spark is too weak. Find the weak point and fix it.

Your cheapest and quickest option is new plugs gapped at .8mm. Go for a good run. You said it took half an hour to misfire before. Try get some heat into it quickly and see if it happens faster.

What colour are your coil packs? Blue means you probably got splitfires. Red means you probably got JJR or superspark. Yellow means you probably got yellowjackets. Black means you either got OEM or nothing has been changed, or some other cheap copy.

[GH05T]

Well their black coilpacks will change them regardless I think, where is a good place to buy them (SA) and how much should I expect to pay?

Also thanks kitto for the helpfull info, I will ask decs to check the tune when I can get the car to barker and have it off the road for enough time.

[kitto]

Well their black coilpacks will change them regardless I think, where is a good place to buy them (SA) and how much should I expect to pay?

http://www.ebay.com.au/itm/DIS-001-Splitfire-Coil-Packs-Nissan-Skyline-GTR32-33-RB26DETT-R32-RB20DET-etc-/190590267877?pt=AU_Car_Parts_Accessories&hash=item2c6010b1e5#ht_1436wt_1396

Dont f**k around with any other coil pack but these as above. You can get cheaper coil packs out there, but my opinion and many others will argue these are worth the money.

To throw another spanner in the works, you could also do an AU falcon coil pack conversion, but this take some time and stuffing around, and then you'll see the coil packs on the firewall. Blah blah blah

$600 for a set of split fires is costly, but worth it. Or hunt around on here in the classifieds, i rekon i see a set come up weekly that has done 10,000kms for around $300 - $400. Just be aware you need the DIS-001, Any others ie DIS-008 etc will not work with the RB20.

Also thanks kitto for the helpfull info, I will ask decs to check the tune when I can get the car to barker and have it off the road for enough time.

<br class="Apple-interchange-newline">

If you literally want him to just check and/or retune the map and you dont want him to do any actual work on the car, then why not just meet him at the dyno? He tunes on a dyno in Salisbury, which is down your way...

[GH05T]

Oh really I didn't know that, thanks for the huge help kitto,

Mow to wait for everything and everyone to re-open from Xmas so I can get shit done

[SargeRX8]

http://www.ebay.com....#ht_1436wt_1396

Dont f**k around with any other coil pack but these as above. You can get cheaper coil packs out there, but my opinion and many others will argue these are worth the money.

To throw another spanner in the works, you could also do an AU falcon coil pack conversion, but this take some time and stuffing around, and then you'll see the coil packs on the firewall. Blah blah blah

$600 for a set of split fires is costly, but worth it. Or hunt around on here in the classifieds, i rekon i see a set come up weekly that has done 10,000kms for around $300 - $400. Just be aware you need the DIS-001, Any others ie DIS-008 etc will not work with the RB20.

<br class="Apple-interchange-newline">

If you literally want him to just check and/or retune the map and you dont want him to do any actual work on the car, then why not just meet him at the dyno? He tunes on a dyno in Salisbury, which is down your way...

There is a guy here selling genuine OEM ones suitable for the R32 and R33 GTR, would they be compatible with his RB20?

You should consider OEM units. People don't because they cost $200 a coil. This guy is selling brand new set of 6 for $350. I bought a set. Awesome stuff.

[DVS JEZ]

The tune will not affect the spark plugs. Your spark is being blown out because the spark is too weak. Find the weak point and fix it.

If the timing is too reterded it is alot harder for the spark to ignite the fuel.

[GH05T]

Ok I'm assuming this is metro be bolted down somewhere not just sitting on the back of my engine!

[GTSBoy]

Yuh, that's the igniter.  It's basically 6 transistors that switch the signal from the ECU into a big enough current to run the coils.  If it has been bouncing around it is probably half stuffed.  It helps for it to be earthed by being bolted down too.

They overheat (or at least get hot, and so when they get old that tends to lead to them overheating) when bolted down to the coil cover.  But when the coil cover is removed, there's nothing to bolt it down to.  So on mine I made a little right angle bracket out of some 25mm angle that bolts to the holes in the cam covers and makes the igniter stand up at right angles to normal.  Does a good job of keeping it still and cooler too.

Edited December 26, 2011 by GTSBoy

[GH05T]

Can I bolt it to the firewall?

[GH05T]

Also are they expensive to get a new one?

[GTSBoy]

It's not convenient to bolt it to the firewall.  The cables aren't exactly long enough (you've got to allow for the engine to roam around a bit under load) and there's still a need to make a bracket.  Just easier to get a short length of angle and drill 4 holes in it.  Couple of extra bolts, washers and nuts and you're away.

I don't know what new ones cost or if they're available. Second hand ones are around, but because they do die often enough that people need them, they do have a desirability tax on them.

If it were me, and I was facing needing a new one I'd contemplate getting some new Splitfires to suit a S2 R33, get or make a suitable coilpack loom and re-wire the igniter loom to hook up to the newer coils. Going to cost a bit to set up, but worthwhile in the long run.

Edited December 26, 2011 by GTSBoy