diagnostic help - rb25 running like poo

[TJ]

car copped a fuel pump the other day

however it was found to be shit

so put another really high flowing pump in it fri arvo

fri night was blowing massive flames so it means there is fuel there.

however on full load it was fart and splutter a little

changed plugs today, went from 6 heat range to 7's
gapped to .6

on boost now it seems fine

off boost , idle etc its running like shit, coughing spluttering etc etc. feels a little slower but more linear once onto boost with some load

ideas etc etc

im thinking

air leak
maybe one plug not gapped
way too much fuel so it cant cope.. doubt it would be off boost though . having said that it does smell of fuel alot now , and pops flames often.

[upgarage]

too much boost

[TJ]

10psi , doubt it

[v8souproar]

just throwing up some ideas

maybe try this 1st

http://www.nissanexa.com/mods/n13/cleancoils/ (http://www.nissanexa.com/mods/n13/cleancoils/)

it may help as it sounds very similar to your prob and it mentions the rb25 as having a prob with the coilpacks.

just being hypothetical here, if im wrong tell me please anyone...

id "say" the fuel mixture would have richened over the entire rev range and
maybe because it could be too rich down low for it too run smoothly and the plugs or ign. system arent coping as well as b4
the hotter pugs may have had their benefits up higher in the rev range where there is more heat and pressure, and possibly the fuel mixture may have leaned out to a better ratio
also at low revs their smaller gap(?) may not have had a decent flame size.

what was the gap on the previous plugs?
giv spitfire, bosch super 4s or ngk iridiums a go, much like a bandaid fix......the better igniting of the fuel may help

if all else fails take it to reputable dyno tuner and they should be able to sort it out.
hope it goes well and
let us know how it goes

-taken from the ngk site maybe a colder plug would be worth a try?
"4. Heat Range

With modified engines (those engines that have increased their compression) more heat is a by-product of the added power that normally comes with increased compression. In short, select one heat range colder for every 75-100 hp you add, or when you significantly raise compression. Also remember to retard the timing a little and to increase fuel enrichment and octane. These tips are critical when adding forced induction (turbos, superchargers or nitrous kits), and failure to address ALL of these areas will virtually guarantee engine damage.

An engine that has poor oil control can sometimes mask the symptom temporarily by running a slightly hotter spark plug. While this is a "Band-Aid" approach, it is one of the only examples of when and why one would select a hotter spark plug."

[magic1]

gap is small. fuel hits plug, clogs plug, stops it firing runs rough stalls
like mine!

or

new piston

[B0BB0]

or the 25 is not happy with its owner :p

no leaks in the cooler piping ?

[TJ]

took plugs out

found one to be overly close gapped ie like .1 or .2

fixed that

now farts around on boost with hard load

grrr @ car

ideas

[SYK STI]

coil pack coil pack coil pack coil pack

[R31 POWER]

If it started only after the fuel pump install then it has to be to rich.Same happended to me,oike really lumpy at idle and missing abit then leaned it up and all was sweet.

[RRob]

Set plugs to .8-.9. Let the computer learn the new fuel mixtures.

[CussCuss]

so you increased the fuel pressure? that would mean that it would be running richer everywhere in the range.
Is an rb25 computer closed loop?

[magic1]

i think it is running very lean in fact so lean that putting fuel in the tank may help some what, try this and let me know.