Help Needed With Diagnosing A Problem

[skyline25t]

Hi, ive had this problem on my car for the last 3 months and havent driven it because of this.... its a new engine and when i first dropped it in ( 4 months ago) it used to have alot of umfff even if i tapped the pedal in 4th gear u used to feel it.. now.. it just sits there.. if i put my foot down it goes alrite to about 4 and then just sits at 4k rpm and just feels liek it wants to due but if i do half throttle it will rev higher.. it just feels liek its back burning like sputtering.. btw its a rb25 r33 i have changed afm, new coilpacks, new spark plugs, new fuel pump, new ignitor module, new coilpack loom and thats about it.. i couldnt think ov it being anything else. need help please

[Jmaac]

did it start doing these things before or after changing these things? Im assuming you have a S1 if you replaced the external ign. module, did u get the right AFM (S1 & 2 are diff). Whats the gap on your plugs etc.

[blitza]

It sounds like its running rich. But I'm no expert

[skyline25t]

lol yep, my mate has a s1 also so i just swapped every part in the fuel delivery system. except for the fuel filter which i'm swapping over tonight and the o2 sensor which i will also do tonight. apart from that im all out of ideas and beginning to think its the engine.. um i duno what gap the plugs are.. i just wound them down. and also thinking mayb a blocked cat.. just eliminating things one by one

Edited May 20, 2008 by skyline25t

[TTT]

good idea to test without cat.

also might be worth getting it on a dyno to see the mixtures.

could be running rich.

any extra boost over stock?

[skyline25t]

um its got a highflow turbo, with a r32 stock actuator so 10psi boost, split dump pipe + 3.5 inch exhasut, cooler pod filter, and thats about it, it used 2 pull reall reall hard but now i cnt even get it over 4k rpm under full load.. the o2 sensor is farked i think also.. coz the wires are liek electrical taped 2gether so i'll see if thats the problem later tonight

[Guilt-Toy]

get a set of spark plugs BCPR7ES and gap them to .7

let me know what happens.

[TTT]

the stock turbo at 10 psi on an RB25 makes it hit r&r.

a highflow turbo with the same boost will be even worse.

The sparkies might help but in reality, some sort of tuning is required.

[skyline25t]

i put a set of NGK BCPR6Es in liek 3 days ago.. im not sure how to gap them correctly

get a set of spark plugs BCPR7ES and gap them to .7

let me know what happens.

[skyline25t]

but it used to run beautifully and then one day something happened and its doing this now.. mayb not 10psi but 7psi..because it could be a r33 actuator i'm pretty sure it is because it would hit r & r..

the stock turbo at 10 psi on an RB25 makes it hit r&r.

a highflow turbo with the same boost will be even worse.

The sparkies might help but in reality, some sort of tuning is required.

[yo-gee-3]

hey there a mate of mine had a similar problem the air intake pipe was too soft and sucked in or collapsed under boost, replaced hose between afm & turbo hasn't had a problem since hope this helps.

[nizmonut]

had similar issues with my 32, rb26det, when we changed the turbo to a garrett 3582 external it was out flowing the stock afm and would start spluttering as the injectors went full duty. it would be okay till about 3500 4000 rpm then would run like dogs balls.

we lenghthened the intake pipe from turbo to afm, changed the afm to a z32 and had a fitting for the recirc valve plumbed to it facing directly back into the impeler on the turbo and solved the issue.

you should at least get on a rolling road and get it tuned properly. it was worth it in my case anyway.

Edited May 20, 2008 by nizmonut

[skyline25t]

i jsut took the car for a quick spin now... i noticed a few other problems..

after a few minutes of driving the the hicas starts playing up and goes on and off repeatedly and the steering is fkt.. also car wont rev above 2k and it seems liek all power it lost and then just dies off by itself.... oh and also the lights start flickering and the rev gauge goes up and down and flickers this is just before the car turns off.

Edited May 22, 2008 by skyline25t

[TTT]

sounds like a bucket of shit. lol..

so all this started happening after the new engine went in?

go back to where you got the engine put in.

if you put it in yourself, it is now time to go to a place that knows skylines.

some things are better left to the experts.

[Adriano]

I would try dropping the cat, check fuel flow/pressure, easiest way is to stick it on a dyno, but to make the most of your setup, your eventually going to really need to get same management. Is it running 10 or 7 psi, it makes a big difference to diagnosing the problem. When it seems to stop, does the boost gauge (im assuming you have one) drop into vacuum, or stay in boost.

[skyline25t]

yeah i did drop it in myself.. the funny thing iz it was working sick for a while but now not so good lol, i'm lookin for a place to take it now.. if anyone is from melbourne do you know or recomend any places that is good value and know there skylines.. i'm in sandringham

sounds like a bucket of shit. lol..

so all this started happening after the new engine went in?

go back to where you got the engine put in.

if you put it in yourself, it is now time to go to a place that knows skylines.

some things are better left to the experts.

[BRUNSKIGTST]

if u want to travel to ferntreegully benno from racepace is ur man trusted by most victorians on these forums 97629421

[nitestalkr]

or you could try RE Customs in westall/springy..

A strange idea for something to check as everything is turning on and off, is your alternator in good condition? I only say that as i have experienced similar probs in cars before which turned out to be that!.. Just a thought seeings engines have been changed etc..

-Daniel