Ceffy Problem. Lack Of Power And Stumbling/hestitating On Boost

[rayj]

hi,

this problem has just appeared. the car used to work really well and ive made no mods to the car.

its an rb20det with vg30 turbo. boost switch running 10 - 13 psi. plugs are ngk copper bcpr7es-8.

this problem only occurs on boost. in the rev range before the turbo kicks in the car drives very smooth with no problems at all, no missfiring or anything.

now when the turbo starts kicking in, it feels like boost is sort of coming on then cuts out, coming on again, then cutting out, on, out, on, out... its stumbling and is very choppy. u can hear the turbo spooling but there is no smooth power delivery...

ive checked the spark plugs for clues. they have this white buildup on the tips. i have never seen this before on this car, its always been much darker. from what i know white buildup means running lean, but why would it start running lean all of the sudden? any ideas? could this be just a boost leak somewhere? anything else?

what could the problem be?

the plugs are new

timing is at 15

new splitfire coilpacks

new walbro pump

thanks heaps

[Chris_A31]

Got a boost gauge? check to see if that's fluctuating when it comes onto boost.

Have you played around with any of the inlet piping recently? check vacume lines to see if any have come off

[rayj]

Got a boost gauge? check to see if that's fluctuating when it comes onto boost.

Have you played around with any of the inlet piping recently? check vacume lines to see if any have come off

unfortuantely i havnt got a boost gauge. ive checked all intake piping, hoses, silicon joiners, and clamps, everything is on nice and tight, but i will recheck it all again today. i really hope its just a leak somewhere...

[daisu]

If you are running copper plugs just run out and get a new set, always good to rule that out first.

Otherwise it's probably your coilpacks on the way out. Try gapping the plugs a bit closer, I think factory is 1.1mm but if your coilpacks are tired try going down to 0.8mm as a bit of a short term solution.

Try swapping your coilpacks with a friend. If your loom has the round shape plugs, they are the same as R32 skyline.

[rayj]

If you are running copper plugs just run out and get a new set, always good to rule that out first.

Otherwise it's probably your coilpacks on the way out. Try gapping the plugs a bit closer, I think factory is 1.1mm but if your coilpacks are tired try going down to 0.8mm as a bit of a short term solution.

Try swapping your coilpacks with a friend. If your loom has the round shape plugs, they are the same as R32 skyline.

these plugs are a brand new set. i have just bought them (bcpr7es-8), and have also tried band new bcpr6es-8. there is no difference. both these sets of plugs are gapped at 0.8mm.

its just my luck that none of friends have skylines so i cant test a new set. im running new splitfire coil packs atm so im hoping they arent dead already, but who knows...

i dont think its the ignitor because ive had problems with ignitors in the past, and this problem doesnt feel the same.

im just trying to see if i can find a solution before i go to a workshop and get it looked at

[Nic_A31]

the plugs are new

timing is at 15

new splitfire coilpacks

new walbro pump

And he's checked the piping.

-----

Try gapping the plugs. Could be fuel pressure regulator (on the rail), air flow meter, throttle position sensor, or ECU related.

Make sure your wastegate isnt jammed or playing up....put mine back on once and it was trying to open 10PSI at idle....computer was having a very hard time working out what was going on.

[rayj]

thanks man, im gonna start checking those things one by one

[rayj]

i was just reading the manual, and it says an automatic should have its timing set to 20. mine is set at 15 degrees...

could this have an affect on the pronlem im experiencing?

[works 510]

dirty AFM?

[rayj]

dirty AFM?

cleaned it with some of that special electrical spray. didnt solve it

looks like ill be taking it to a workshop

[adrnln]

Is is happening at a certin RPM like around the 3k mark?? and as you try to boost it cuts out or is it on off through out the rev range??

[rayj]

Is is happening at a certin RPM like around the 3k mark?? and as you try to boost it cuts out or is it on off through out the rev range??

yep thats what its exactly like.

its at boostworx now, just dropped it off

[daisu]

unfortuantely i havnt got a boost gauge. ive checked all intake piping, hoses, silicon joiners, and clamps, everything is on nice and tight, but i will recheck it all again today. i really hope its just a leak somewhere...

Do you have access to an air compressor? If so, remove your AFM and plug the pipe (I used an empty glass jar), then pump the air in through a vacuum line. You'd be surprised where the leaks are. Don't need to go any higher than 1bar.

On my old RB20, it was leaking around where that rubber hose connects to the crossover pipe. A few vacuum lines I had plugged with bolts were leaking around the bolts. One of the pipes was leaking at a weld. A common place is the gasket between the upper and lower inlet manifold.

EDIT: Just saw above post. Hope they can sort it for you.

Edited July 12, 2010 by daisu

[rayj]

Do you have access to an air compressor? If so, remove your AFM and plug the pipe (I used an empty glass jar), then pump the air in through a vacuum line. You'd be surprised where the leaks are. Don't need to go any higher than 1bar.

On my old RB20, it was leaking around where that rubber hose connects to the crossover pipe. A few vacuum lines I had plugged with bolts were leaking around the bolts. One of the pipes was leaking at a weld. A common place is the gasket between the upper and lower inlet manifold.

EDIT: Just saw above post. Hope they can sort it for you.

i wanted to this but i couldnt access to a compressor. i can imagine finding alot of leaks all over the place.

cheers man

[adrnln]

yep thats what its exactly like.

its at boostworx now, just dropped it off

With mine it was one of two things- a faulty ignitor, instead of trying for second hand ones I rang mircotech see comments below.

Ok so rang John at Mircotech 02 49661234 and they do NEW 4 and 6 channel ignitor packs with loom to replace the old ones. So you can replace yours on your RB20 SR20

So all you need to do it cut and re wire this into your harness and you have a new ignitor pack no second guessing anymore.

Second thing it might be is a loose wire on the ECU where the wires actually go into the plug that you put into the ECU. Have a good look at the wire going in to see if their is no damage to any of the wires.

These are the things I did to get my issue fixed which sounds like from your discription what I had.

[rayj]

im happy to report my car is now fixed and driving around beautifully. thanks shaun and boostworx

turned out to be a faulty CAS...

[adrnln]

CAS??

[S1LV3RTRACKS]

CAS = Crank/Cam Angle Sensor.

[adrnln]

Cheers