Misfire After Tune Rb20det R32 Pfc

[ashr32]

Hey Guys,

Quick question, car just got tuned at Chasers

related Mods:

pfc

rb20det 125,000kms

hks 25/30 turbo

z32 afm

stock injectors

bcp7es plugs .8

fpr 85psi (to max injectors)

arc airbox

isc cam gears

new fuel pump

Yellow jacket coil packs

215kwatw (Very Happy)

After the tune Paul at Chasers said I should change to heat range 8 plugs to be safe as it will be seeing heavy track work next year.

Im about to get them but wanted to know what you guys are using?

pretty sure Paul recommended NGK Bcp8es gaped to .8

Will the 8's get any start up/misfire issues?

thanks guys

Ash

Edited December 29, 2009 by ashr32

[R31Nismoid]

Side note...

When you say 85psi FPR... is that 85PSI BASE pressure?

Or 85psi @ "X" boost leve you are running?

If its 85 BASE, then that is over double factory before you even begin... very bad, will be over 100psi once you get boost

[zebra]

why use a .8 gap if you dont have to...start with 1.1 and then if it misses under high load start dropping the gap down in .1 increments untill it stops.

Id also think that plugs that cold would foul pretty quickly, even on the track.

[STATUS]

First things first change injectors and get the thing safe, a tune (no matter the tuner) based on a highly strung FPRis a reciepe for disaster on a track car... forget plug heat range the 7's will be fine.

also check the coil packs ive had a few sets die.

[Guilt-Toy]

yeah 85 base is pretty high.... what fuel pump are you pushing that pressure with? please dont say walbro.

[Dose Pipe Sutututu]

Your misfire issue will come from your car leaning out rather than the plugs, I recommend getting 440cc GT-R injectors & make yourself a resistor pack from Jaycar.

[ashr32]

yeah 85 base is pretty high.... what fuel pump are you pushing that pressure with? please dont say walbro.

Ok so now im worried, when i took the car to get tuned it had an aftermarket pump but Paul said that it was failing. Even though it was only a year old.

So he put a new pump in and yes its a walbro but they couldn’t tell me the model....

They charged 200ish plus install 270l/min im guessing.

The fuel pressure reg is a shitty "Drift" brand one that i picked up the night before the tune as i initially had gtr injectors but 2 were faulty so i thought at least id max the stock ones for now.

The think is the reg is raising rate but when looking at the gauge it just sits at 85psi and doesn’t move up or down on boost?

Guilt-toy- so im i going to have immediate issues? the first track day is on the 17 january at Sandown

[ashr32]

Side Note...

I had a run against a 5 litre VN SS with a cam last night. good run but i had him easy. I took a pic of the peak level on the hand controller afterwards.

The Knock is higher than its even been but i hit the limiter in second as the V8 was so loud i could even here my car. The knock level on the dyno was 15 - 20 and so far on the street its been about 25-30

related???

that tests can i do. I know the basics but the pfc is new to me and i prefer to as the guys in the know first.

thanks guys

[R31Nismoid]

Don't street race you stupid boy. Least of all brag about it on this forum - quick way to earn yourself a ban. We do not tolerate it.

Walbro's simply do not perform well under higher pressures consistently, i've not seen one that does. Mine sure as hell didn't.

Hence it is now a low pressure lift pump for my surge tank.

They are better suited to N/A applications basically.

So its 85psi base when the car is idling? jesus... you sure its not increasing on boost?

It all sounds to dodgy/backyarder IMO. I certainly would not be track racing such a questionable setup as with such high pressure's etc.

Something even slightly goes wrong, off for a new motor you go.

[ashr32]

Don't street race you stupid boy. Least of all brag about it on this forum - quick way to earn yourself a ban. We do not tolerate it.

Walbro's simply do not perform well under higher pressures consistently, i've not seen one that does. Mine sure as hell didn't.

Hence it is now a low pressure lift pump for my surge tank.

They are better suited to N/A applications basically.

So its 85psi base when the car is idling? jesus... you sure its not increasing on boost?

It all sounds to dodgy/backyarder IMO. I certainly would not be track racing such a questionable setup as with such high pressure's etc.

Something even slightly goes wrong, off for a new motor you go.

R31Nismoid - thanks for your opinion, so i take that the reg is faulty as doesnt go up in pressure with boost?

i cant find any 550cc at the moment or else id buy them, also Chasers done come back from xmas leave till the 12th i think.

what reg should i use and what should it be set to then?

Edited December 30, 2009 by ashr32

[STATUS]

Walbro's simply do not perform well under higher pressures consistently, i've not seen one that does. Mine sure as hell didn't.

Hence it is now a low pressure lift pump for my surge tank.

They are better suited to N/A applications basically.

So its 85psi base when the car is idling? jesus... you sure its not increasing on boost?

It all sounds to dodgy/backyarder IMO. I certainly would not be track racing such a questionable setup as with such high pressure's etc.

Something even slightly goes wrong, off for a new motor you go.

Damn walbros and denso pumps, i just opened up today for a customer in dire straits..... car was backfiring put it on the dyno and it was dropping fuel pressure.... pulled out the pump and what do you know WALBRO.... put it in the bin and fitted a Bosch 040 and bingo fixed.

Hate them with a passion.

[Roy]

I am with others in saying i would miss the first Sandown day you were hoping to run and make sure everything is sorted.

Get am 040 Bosch or an in tank HKS/Nismo etc fuel pump and throw away the fuel reg. RB20s are damn tough and will be reliable at 230rwkws, but you need to make sure the fuelling and cooling is right before going to a place like Sandown with such long straights where you will be up the car for all money

[ashr32]

I am with others in saying i would miss the first Sandown day you were hoping to run and make sure everything is sorted.

Get am 040 Bosch or an in tank HKS/Nismo etc fuel pump and throw away the fuel reg. RB20s are damn tough and will be reliable at 230rwkws, but you need to make sure the fuelling and cooling is right before going to a place like Sandown with such long straights where you will be up the car for all money

Thanks for the info roy i was hoping you would see this, The track day is paid for so if i don't go i lose money and the hours ive spend putting it together.

so guys i need to know my options

1. Get a 040 bosch and removed the reg. pump = $200ish (cheap)

would i need to get a retune?

2. get a set of new injectors (550cc) and a retune ($$$)

3. My friend has the same pump but hasent put it in his car yet, so could i run 2 inline?

there wont be very much time between Chasers opening and the track day so i'll be lucky to get in in time.

Any other ideas guys?

[paulr33]

to save some $ fit GTR injectors, 440cc is better than 370cc and fit a new fuel pump

the fuel pump is the achilies heel of the engine if not done correctly

if its weak or mangled, the engine will fail, period

if the pump fails, its ok, as the engine stalls, its only when it leans out or can't keep up (but continues to pump some fuel) that the engine goes bang

mangled or cheap walbro's are known or not being able to keep up as ash and trent have said, so stay away

[NZM.031]

sell your drift brand fpr and your walbro pump, find used GTR (440cc) or rx7 (550cc) injectors and gtr fuel pump, put the stock pressure reg back on. the gtr fuel system can happily support that amount of power.

ive done the max injectors thing before on an rb25 as i couldnt just get some rx7 or gtr injectors... it worked... but i wasnt real enthused on it. and on hot days it was a bit of a worry.. even though i had a gtr fuel pump as a lift pump to a big bosch pump and a nismo fpr.

[Don Dada]

Siht! 85psi base pressure! Is there any vac lines going to the reg or does it even have a nipple for one???

U guys don't really like Walbro do u?

Again, i think a lot of ppl use the wrong model.... cant remember the one recommended for turbo apps right now.

Have had mine for almost 3yrs now and its currently running my 26 at 40psi base and afrs going to 10s up in the rev range(stock ecu)

[NZM.031]

walbro just arent as good as bosch is all that it is... and when the entire car relies on the one part.. is it worth it to get second best?? no serious circuit car or time attack car, or drag car uses walbro pumps. your $100000 rb26 with a T51R, 1000cc injectors, etc. etc. aint gonna be much good without a decent pump is it.

[daisu]

The bosch fuel pumps are rated for higher pressures than the walbros.

Admittedly, I am running a walbro at the moment, but it's basically a standard RB20 and I will be getting a proper lift pump and a bosch when I put a surge tank in.

In this case, I'd go back to standard FPR, a bosch pump, larger injectors, retune.

The money/time lost by missing a track day would be far less than compared to having to repair a damaged engine.

[Don Dada]

walbro just arent as good as bosch is all that it is... and when the entire car relies on the one part.. is it worth it to get second best?? no serious circuit car or time attack car, or drag car uses walbro pumps. your $100000 rb26 with a T51R, 1000cc injectors, etc. etc. aint gonna be much good without a decent pump is it.

Walbros are good....just up to what power level is the real question.

Will u run your $100000 rb26, t51R, 1000cc blah blah with a 044 bosch???? I don't think so...

Even the 044 will run out of flow at some point but that does not means it is shit.

For 215rwkw the 255lph walbro is sufficient.....

I mean if its standing up to 85psi base pressure and still flowing enough for it not lean out at 215rwkw that has to count for something!!!

How long will it last???? Thats another question

[Roy]

Dont stress too much about injectors, throw an 040 in there and remove the fpr and just drop boost a little and run 180-190rwkws for the day. When you have found a good set of injectors then you can firt them and get a proper re-tune.

I would suggest that after fitting pump , removing fpr and dropping boost you at least have it looked at on a dyno. I may be selling my GTR injectors which are currently in my car and running perfect, but i need to find some 700cc myself