Fouling Plugs On My Rb30

[FAT_3L]

hi guys got a drama ive been having for a few weeks and need some advice so here goes...

I have a rb30et fairly worked, i had the engine in another car until my brother crashed it for me.

Now i had a mate install all my running gear into another vl and mounted my coils in a different spot, this is the only difference from my other car.

I had the car defect almost instantly when it got onto the road so it sat in my shed for around 6 months, modifying it for my engineers cert. It was started regularly still.

I have finally got the car legally road registered and now i keep blowing the plugs!!

I thought it was just way out of tune so i took it to my tuner. He dynoed it for me and he said it read as everything was fine. That day i drove it home and replaced my plugs. 4 days later they fouled up again, not all 6 this time just the back 3 (4,5,6). First 3 were fine so i replaced them again thinking they may have been faulty.

1 day since replacing them i have blown them again!!

Compression reads around 125psi over all 6 cylinders. My tuner said that is about right due to my setup and cam.

My tuner is well known for tuning microtech's aswell!!

I just dont understand what it could be!!

Any help will be appreciated

Thanks in advance...

Kris

[blind_elk]

Do you get the engine up to proper operating temperature? It will run very rich while cold.

[tridentt150v]

Was crash a roll over?

[R31Nismoid]

Didnt your tuner offer some advice if he is well known?

Could be many things.

Please list the full spec. Because you said coils, i assume your not running factory ignition either ye?

[T04GTR]

ok. well theres some reason for it. what sort of microtech is it? and was the wiring redone? it sounds like the ecu or the wiring for the injectors.

we fitted a brand knew haltech a while ago and had to send it back cos it was fouling no3 plug. new one. al fixed

[NXTIME]

Who's your tuner?

[Guilt-Toy]

what plenum does it have? and what fuel pressure reg? have you checked for irregular fuel pressure? take pics of the plenum and post it

[FAT_3L]

blind elk - the car will run rich when it is cold but pretty well when it up to temp!!

tridentt - Nah crash was at the side toward the back witha guardrail.

T04GTR - Microtech is a ltx12. it was a brand new loom when it was installed on the old car and i guess nothing has changed since unless something when wrong when getting installed. But wouldn't something ke that show up on the dyno??

NXTIME - Formally Rx Engineering turned to Blacktrack Performance

Guilt-toy - Its a custom plenum and not sure what reg but is new from autobahn. only one i could get at the time! and yeah the fuel pressure is reading good!

http://img263.imageshack.us/my.php?image=k...ncars021tx1.jpg

Heres the pic the some specs on the car,

NOTE: coils were mounted there but since have been moved onto the chaiss rail underneath the plenum after i encounted the problem because it was earthing on the firewall every now and than but not on the back 3 cylinders coils.

R31 Nismoid -

Engine management is a microtech ltx12. 6 individual bosch coils,. the head has been rebuilt with a stage 3 cam, good port and polish, new valve springs, lifters etc. The bottom end has standard rods, arias forged pistons (20 thou), not sure about rings thou (which is what im thinking but hopefully not), Turbo is a t04 highmounted, custom plenum and fuel reg, 550cc injecters (RX7), 450hp external pump.

Thats all i can think of at the moment, if u require any more infom just ask. thanks for ur help so far!!

Also the car has made 380hp on 14psi but on the last tune it made 340hp on 15psi ( i think the dyno was out but i have given you the info incase the problem may cause the loss in power)

Edited May 23, 2007 by FAT_3L

[FAT_3L]

anyone got any ideas,need to fix this asap!!

[blind_elk]

What plugs are they? Gap?

[rob82]

Leaking injectors?? How does the car hot start if you leave it for say 30 min.

[FAT_3L]

blind - they are standard plugs for a vlt gapped to .8mm. i have tried hotter plugs but they do the same just not as quick!!

rob82 - everytime i start the car after driving it for a while or at all at that, i need to give it a good rev so it will idle properly, otherwise it will stall or go very close but once i do that the car will run fine up until the plugs start to break down or i turn it off!!

Edited May 25, 2007 by FAT_3L

[T04GTR]

yeah. time for a "decent" tune, whayt afr is at idle??? exacly

[Adriano]

I would get the injectors looked at, at the best of times, rx7 injectors have a poor spray pattern not really suited to iston motors, yours may just be dirty. When you say they are fouled, do they come out smelling fueley or are they just black?oily?

Edited May 25, 2007 by Adriano

[Adriano]

How many ms duty cycle are you running on the coils?

[FAT_3L]

T04GTR - It just had a tune. if i turn the ignition on it may tell me the afr on the hand controller but im not to sure what the afr will be idleing at the moment as i am relocating the coils and havn't wired it up yet.

Adriano - it's only the back 3 plugs that are fouling up. the front 3 come out perfect while the back the are very fuely, dont think its oily

[Al]

rob82 - everytime i start the car after driving it for a while or at all at that, i need to give it a good rev so it will idle properly, otherwise it will stall or go very close but once i do that the car will run fine up until the plugs start to break down or i turn it off!!

Sounds like it could be a number of problems

- wiring

- tune

- posible leaking injectors

- ecu

- etc.

Take it to a another mechanic who can diagnose the fault and sort out the issues. On the net you will just get a whole heap of "maybe's" but no real solution.

Not being rude/smart/etc., but why post up on SAU, when there are SOOOOOOOO many VL / Commodore forums that have better experience/knowledge on the RB30et. Even the R31 forum would likely know more and be of greater assistance.

[FAT_3L]

because here i have actually recieved some help off people that offer there experience and knowledge. i never even know of the r31 forum but will try there.

as for a machanic most of them here talk crap just to get your money and don't fix the actual problem, and i can't drive it at the moment anyway because i havn't finished wiring my coils!!

[FAT_3L]

anyone else got an idea???

[rob82]

Still reckoning its the injectors leaking - get them ultrasonicly cleaned and flowed. But in saying that I havn't seen the tune which may play a major part in the saga.

Edited May 28, 2007 by rob82