Jump to content
SAU Community

Recommended Posts

Hey Guys, seeking some wisdom / advice.

A bit about the car. The car is a 99 Stage RS4-S factory manual has turbosmart duel stage boost and FMIC, boost running at 4pound and 9 pound, other then that its stock.

The problem i'm having is under load around 4000 and 6000 rpm i get a stuter / surge. It doesn't happen all the time but I would say 40% of the time sometimes it's v.minor and other times it is more pronounced. Not being a mechanic and reading skylines Australia I thought must be coil packs.

I took the car to a mechanic mate of mine today to see what he thought and to pull the coil packs (standard) and plugs (iridium) for a check. He took it for a drive and was 100% sure it wasn't a missfire and though it felt like a limiter feel. He then checked the ECU using a diagnostics computer and found 55 No fault found which indicates not a missfire problem.

He then asked the apprentice cos he had some experience with skylines, the apprentice reckons its a wastegate problem and to test it remove the vacuum hose of the standard blow off valve and plug the hose with a bolt, take it for a drive and see if it happens (the vacuum hose pic is below). So I did that and although it had less power it didn't have that stutter problem. (What does this test prove, does it prove it is a shagged wastegate? Im no mech so I got no idea)

Any thoughts as to what it could be? Wastegate, acutuator, something else?

Cheers,

Brad from Cairns

post-69406-1273907970_thumb.png

Edited by BCCairns
He then asked the apprentice cos he had some experience with skylines, the apprentice reckons its a wastegate problem and to test it remove the vacuum hose of the standard blow off valve and plug the hose with a bolt, take it for a drive and see if it happens. So I did that and although it had less power it didn't have that stutter problem. (What does this test prove, does it prove it is a shagged wastegate? Im no mech so I got no idea)

?????? Well im no mechanic either but that is a little weird. Although being able to run 4psi is also weird? perhaps ur guage reads a little low?

I can't see how that would prove the wastegate is stuffed. It really does sound like coilpacks (or possibly fuel pump?) do you know anyone who would lend you a set to try?

Personally I would find a dedicated performance workshop and get them to have a look. Any decent workshop should know RB25s :)

(also pretty sure error code 55 indicates no errors found lol so your mechanic might not be too savvy with the imports)

Edited by streatracer

the only thing that removing the vac line off the BOV proves is the apprentice isn't as crash hot on skylines as he thinks, blocking the BOV line will have no influence on the wastegate. without that vac line the BOV could now be blowing open under boost hence the lack of power you feeling after blocking it.

it still could be a slight breakdown/misfire issue, it won't show up on the DTC's unless a coil pack or PTU completely fails, thats why you have no error codes. when you say its like a limiter how does it feel? i mean, is it a violent stutter, a complete engine cut, or just like the power has flattened out a bit?

A couple things that would be worth doing are, change the plugs out for a set of coppers gapped to 0.8, and change your fuel filter if you haven't already.

Edited by QWK32

Cheers for ya thoughts, the 4pound low boost is a bit of a guess. Its tricky as the stock boost gauge in the middle of the dash isn't working and the aftermarket boost pressure gauge seems to be around 4 when accelerating (its the wifes car so i use the low boost setting =).

I think that apprentice mechanic has no idea about turbo systems. So long as the car makes the same amount of boost through the area that you have the problem (4k - 6k) it won't be a wastegate problem at all. The only thing the wastegate could do wrong is cause a spike in boost and you are hitting a condition called R&R, it's a factory safety thing so protect against spikes in boost, basically retards the timing and adds heaps of fuel, and you'll loose power there. But if you are still seeing 4psi, then that can't be the problem.

I reckon you might have a poor spark, try gapping down your plugs (take the plugs out and make the gap between the electrode and the plug smaller. This should improve the strength of the spark.

Cheers heaps Josh thats helped me think about the prob a bit differently.

If I had to chose between 'violent stutter, a complete engine cut, or just like the power has flattened out a bit' I'm leaning towards power flattened out a bit, and sometimes mild, stutter when it powers back. Because it only happens under full load if the power flattened out and it kicks in then the whole things would seem a little harsh.

As for the blocking of the BOV vacuum from what your saying if it was underboosting then it wouldn't be putting load on the ignition and as such no missfire. Which leaves me thing coils and plugs (which seems so common)

Thanks heaps again.

mine surges under heavy load sometimes - not massively but its there

i'd say its coilpacks starting to let go

the dont suddenly fail, just get worse

if you can find some liquid neoprene you can coat the coilpacks in that to insulate them and hold them off from failing for a bit longer or high temp silicone is good too

or just replace them - yellowjackets will set you back around the $400 mark and will be good for quite a few years to come

splitfires will last a bit longer but cost more

I think that's the only direction I can go.. I'll do some copper plugs at 0.8 and neoprene up the coil packs and see how i go. I'll let ya know.

Went for a few beers last night with me mech mate and he just doesn't reckon its a missfire.. He said he could be wrong because hasn't worked on Skylines but he said it ain't like any hundreds of missfires he has felt and fixed on run of the mill cars e.g Fords, holden and NA engines. Makes it hard cos I have no idea what varying degrees of missfires feel like.. And its realy hard to describe a problem to diagnose over the internet.

So I went looking on the net and found this video on youtube, and as far as video goes (to varying degrees) the popping / stuttering is exactly whats happening to me. http://www.youtube.com/user/syncore34#p/u/9/EOWmMYv86_w

wish I could find this Syncore34 guy see if he fixed it.

Edited by BCCairns

it cant hurt to do that

i rate coppers better than platinums or iridiums

and .8mm is a good gap to go to if your uncertain if its coilpacks

failing coilpacks usually go out slowly in skylines so they could easily be on the way out

Cheers guys you were all on the money, nothing to do with a wastegate etc..

So tonight I threw in some copper NGk's gapped at .8mm. Visual inspection of the coils looked pretty good. Could see 1 coil had some feint white lines from what looked to be a tinny gap in a seem. It's the wifes car so i needed to have it on the road tomorrow so I just wrapped that coil with electrical tape.

I then set off for a 10 minute test run, boosted through 4k to 6k rpm no probs at 8psi. After about 6 mins of boosting around, it did start hesitating slight, but nothing like and it still boosted and powered through the hesitations.

So conclusions it's got to be one or more coil packs braking down. Looks like I will be breaking the sealeys 401 silicon on the weekend, then failing that forking out for yellowjakets.

Will keep you posted

Cheers guys you were all on the money, nothing to do with a wastegate etc..

So tonight I threw in some copper NGk's gapped at .8mm. Visual inspection of the coils looked pretty good. Could see 1 coil had some feint white lines from what looked to be a tinny gap in a seem. It's the wifes car so i needed to have it on the road tomorrow so I just wrapped that coil with electrical tape.

I then set off for a 10 minute test run, boosted through 4k to 6k rpm no probs at 8psi. After about 6 mins of boosting around, it did start hesitating slight, but nothing like and it still boosted and powered through the hesitations.

So conclusions it's got to be one or more coil packs braking down. Looks like I will be breaking the sealeys 401 silicon on the weekend, then failing that forking out for yellowjakets.

Will keep you posted

G`Day ,

Silicon ???

May be try URETHANE SEAL COAT,i use this on my COILPACK`S & dose great JOB & is not MESSIE like SILICONE,

Done few set`s for mate`s & works great, spray them any colour you like once coated,

i have POSTED in few theard`s so hope it`s a HELP,

+ iam now trying to use a FIBRE WASHER under COILPACK`S to reduce the HEAT in to COIL`S hope it work`s & may help other`s again,

Cheer`s Chuckie .

read this

http://www.skylinesaustralia.com/forums/Dy...ry-t320073.html

post # 11 from STATUS

r34 is even worse than r33 ecu

my car is the same as yours . i have it right on the limit of doing it . depends on the weather

G`Day ,

Silicon ???

May be try URETHANE SEAL COAT,i use this on my COILPACK`S & dose great JOB & is not MESSIE like SILICONE,

Done few set`s for mate`s & works great, spray them any colour you like once coated,

i have POSTED in few theard`s so hope it`s a HELP,

+ iam now trying to use a FIBRE WASHER under COILPACK`S to reduce the HEAT in to COIL`S hope it work`s & may help other`s again,

Cheer`s Chuckie .

the fibre washer wont do much . might make matters worse actualy as the spark plug boot wont fit on the sparkplug properly

once they have been cooked for 10 years they are f**ked .

fibre washers would be preventitve . not corrective

Cheers chukie, I will give that urethane seal a go for sure. I did forget to mention I do have a After market boost gauge.

So Lachlan are you saying you can't boost reliably above 8psi on your s2 rs four s? I went for a drive today, at 8psi nothing was failing for a good 30 mins so I thought bonus I will up the boost. I upped it 2 clicks so I guess that would be around 9psi and it consistentl hesitate in 2 spots around 5500 and 6500, it was nothing like the original prob I had, is this the r&r? or the thing u refer to in post 11 at

http://www.skylinesaustralia.com/forums/Dy...ry-t320073.html

Hi Well i will try Washer`s TO SEE IF it will help & try few more bit`s later on ,ONLY looking to see what WORK`S & WHAT DON`T

just need to try different thing`s see what happen`s ,COILPACK only have very small crack`s so eruthane will fill them & work`s well,so far lol.

Cheer`s Chuckie.

Cheers chukie, I will give that urethane seal a go for sure. I did forget to mention I do have a After market boost gauge.

So Lachlan are you saying you can't boost reliably above 8psi on your s2 rs four s? I went for a drive today, at 8psi nothing was failing for a good 30 mins so I thought bonus I will up the boost. I upped it 2 clicks so I guess that would be around 9psi and it consistentl hesitate in 2 spots around 5500 and 6500, it was nothing like the original prob I had, is this the r&r? or the thing u refer to in post 11 at

http://www.skylinesaustralia.com/forums/Dy...ry-t320073.html

with the reference to the link, if your engine is 100% ie no dodge coils, there will still be a small flat spot around 4800-5200 rpm, almost like power eases off for a sec then kicks back in. the engine will seem to be running fine and rev smoothly during this flat spot. i could really notice it at 11psi on stock maps and turbo.

when a coil pack is breaking down / miss-firing you will notice the engine run a little rough, probably more noticeable with a aftermarket exhaust system where you will hear the engine's note stutter, cough or even backfire.

you wont be feeling R&R if you say it is only hesitating during a small rpm range and running fine and "full" powered the rest. once you hit R&R the ecu will stay on the knock maps for a while (i think until restart), so the car will feel sluggish and slow through the whole rev range while in R&R.

i've seen chuckies post with the pics of his coil packs sprayed in that crc urethane stuff he is talking about. that stuff looks like it seals the coils up really well and about 100 time neater than pumping silicone all over them. i say try that first, it cant hurt and its cheap and easy.

Sound like a plan, I'll do these coils then worry about getting to 10+psi.. I forgot to mention in mods I do have 3"inch system from the manifold (*blames forgetting to mention earlier on new born baby distractions =)

I've been searching the forums and it seems like something is fishy with Rs4 s and getting the boost above 7 psi due to sensitive ecu and boost limiter solenoid so thats a likely cause of my new higher boost problem. http://www.skylinesaustralia.com/forums/Bo...43#entry4940243

think i mite have to get a nisstune if i want to get to 10psi. or do that plug the tube to solenoid mod but im not so sure how safe that is ?

thanks again, for ya help ppl

Edited by BCCairns

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...