Rb25det Problems..

[sidewayssam]

hey just a quick question, a mate of mines has a r33 with aftermarket turbo, intercooler, exhaust, computer, 800hp fuel pump and lately its started to run rough, he had to put 95octane fuel in it the other day and thats when the probs started, weve changed the fuel filter and plugs but still when it stars to boost it starts sttuering like its havin fuel surge and backfiring, has any one else had similar problem? what should we check next? injectors or coils??? cheers

[Garret_Volden]

hey just a quick question, a mate of mines has a r33 with aftermarket turbo, intercooler, exhaust, computer, 800hp fuel pump and lately its started to run rough, he had to put 95octane fuel in it the other day and thats when the probs started, weve changed the fuel filter and plugs but still when it stars to boost it starts sttuering like its havin fuel surge and backfiring, has any one else had similar problem? what should we check next? injectors or coils??? cheers

thats exactly what my car is doing right now

it did it when i had my old 2 litre in it and i swapped in a neo and it still does it

the only things that are the same are the fuel pump,which i changed,the boost controller which i am changing tomorrow,and the maf.

so my guess is that the boost controller or the afm is not working properly,because it only happens under boost.

so try checking the boost controller and the maf

i will update if this thread when i figure the problem out,but i am fairly certain it is my old shitty manual boost controller sticking.

cheers!

[sidewayssam]

ok cheers for that ill have a look and il let u know

chees

[VB-]

happen at any particular RPM range? under high load only?

[sidewayssam]

happen at any particular RPM range? under high load only?

yeh pretty much from bout 4000 and up when u put ur foot into it

[Spunky Munky]

Sounds like you need a good tune... you got an aftermarket ecu?

[sidewayssam]

yeh its got aftermarket ecu and recently had full tune by imports101, could it be a problem with the stock injectors? its my mates car, me and him both had to fill his skyline up and my ss up with 95octane wich our cars dont run too good on, after that i had similar probs with the ss but i changed the plugs and and me valkve springs at the same time n it came all good but the skyline just gettin worse

[TTT]

when you changed the plugs in the skyline, what plugs did you use?

and what gap?

May be a stupid question but have you got rid of the 95 fuel yet?

if not, maybe buy a bottle of good octane booster and dump that in the tank with the 95.. it should bring it's rating back up to 98 or so.

[sidewayssam]

we didnt check the gap we just got some new ngk ones from repco and just assumed the gap would be fine, yeh we drained the fuel and ran injector clean through the engine and now are runnin it on 98octane ith octane booster,

[TTT]

if you still have the plug packs, see what the part number is.

they usually go BCP..... 11

or BCP....8

if it's 11, then you'll need to re-gap them.

it might be all it is..

and it's only 30 minutes of your time and no extra money.

[sidewayssam]

yeh ill check that tomorow aye, i dunno if it is the plugs tho coz the problem didnt change at all after the plugs where changed, anyway ill check em tomorow n get to u, cheers

[TTT]

it may be that the last plugs for fouled so you were missing.

now you have new plugs, but they "may" have too large a gap so you are getting a miss due to spark being blown out..

soo same type of symptoms stemming from slightly different spark related issues.