Jump to content
SAU Community

Recommended Posts

Has anyone Had this problem.

I am running fmic,bov,3.5 zaust, boostcontroler,ect, and my car seems to have pot,pot,pot noise through the zaust, noise begins at 5000 as boost starts to really get going( i loose boost also), It does this on high and low boost whats the problem? the zaust has only been on the car for a month and it was running fine for the first few weeks! ..........................help! whats wrong!!:P:):D;)

Link to comment
https://www.sau.com.au/forums/topic/5643-loosing-power-at-5000rpm/
Share on other sites

took it to a mechcanic last night and i have booked it in to test the fuel mixture through the rev ranges. He looked at the exhaust and said it might be running lean. So I am not driving it at the moment until I findout whats wrong!

I don't think the sparkies have the wrong gap setting as they were just put in two months ago platnium ngk plugs gap set at 0.9 think thats what they were!

I hope it just a blocked injector or something!

:)

Take notice of what you were told dude..

I had the EXACT same problem and the HITMAN told me ALL boosted skylines have that problem with the plugs being set to 1.1 at more then standard boost.

I was told by the HITMAN to set them to .6 and it stoped straight way.

Once it passes the popping point it keeps going hey?

Take your car back and try it. or tell him to set them to .6 or .8

Worked for me.

the pop pop noise is because its running rich as the sparkies arent creating a reliable spark under high boost. ive got the same problem at the moment but have been too lazy to regap the plugs (damn uni exams)

0.6 is too close. i say between 0.8 and 0.9 should be fine. but it depends what boost u running?

I have a very bad miss at about 4500 rpm and after puting it on a dyno to see what was going on they told me i had 2 coils (1&5) that were breaking down, so i replaced both of them and the miss is still there. I am running 1.3 bar with a .8 gap. should i run a smaller gap ? if so, then why would it only break down on 2 cylinders ?

i assume AFs are fine... other thing to check is timing advance cos this is obviously an ignition problem

i know you run a closer gap with higher boost pressure however i dont know how close your supposed to go... at 1 bar (what im running) im going to run 0.8 so i guess you should close the gap more...

why is it at 4500rpm? is that when full boost hits? does the car keep going after that point? unforunately there are quite a few things it could be

I got a fuel air mixture reading done on my car to see if it was to rich or lean but it was fine. they said it might be 2 faulty coil packs that could be the problem, same as what JAPSIX said about his ride!....... but first thing is that I am going to change the gap size on my sparkies they are 0.9 will drop them back down to 0.8 or 0.7 and see if that works. thanks for the input!

:)

Yes my a/fs are fine, they checked it on the dyno.

I rang my tuning shop today and they said to try a .65 gap, so i will do that tomorrow and if that does not work then i will try a different ignitor.

If i turn my boost down below 1 bar then there is no problem and when i run over that it only misses once the car is fully warmed up. I have about 15 psi at about 4000rpm and the miss is sometimes inconsistant. Sometimes it will miss a bit then let you rev it out but most of the time it misses real bad and i back off.

mine are 0.6 gap and she's running fine I thought the same that it might be too little but its fine I'm running NGK iridiums...gotta gap em down or play with the ignition timing as well that can cause part of ur problem...

I would try advancing your timing to 20-25. I had same problems, at exactly 4500 to 5500rpm then fine until redline. Changing the timing totally fixed it.

As a quick review here are some common cause of the surgin/popping etc

spark plugs farked/gapped wrong

Timing

Air Flow metre shagged, faulty or dirty

far to rich or far to lean (on stock usually to rich, on boosted line usually a bit to lean so ecu retards the hell out of the timing)

Hitting boost cut due to leaking/inaccurate boost guage (Says 12psi, but maybe spiking to 14-15psi)

I'm sure there is other reasons, but most of these should be free or very cheap fixes.

Good luck with fixing it.

Cheers,

Tim

Hi

I don't have many mods (well cat back zorst and pod) and I noticed mine having a bit of a lumpy "pop" noise in the zorst at idle which wasn't so noticable during driving but no doubt still there. I went thru what you're experiencing. Turns out my injector in cyl 6 wasn't closing off and had overfueled the cyclinder and washed all the oil away from my valves, significantly dropping my compression in that cyclinder.

Long story short, do the following:

1) Clean out your AFM, you'd be surprised how much cr*p gets built up in that little item.

2) Clean out your injectors - probably can't do this yourself? Find someone that can.

3) Get new sparkies if necessary. I haven't gapped mine but as I said, i'm pretty standard.

4) Get someone to perform a compression test on your cylinders.

Other than that, I can't help :headspin:

Cheers!

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


  • Similar Content

  • Latest Posts

    • So stock ECU does not like anything above 10 psi?  That Nistune one is just for "try" if it will be any different, I know it need to be tune for that. I know but YOU may know about these problem but i/we dont. They few little Skylines here let alone people who know anything about tham so that is why iam asking here  
    • So now we have a radiator with no attachments whatsoever. It lifts up with a particularly tight spot between the drivers side air box mount and the lower radiator outlet, but if you've got this far you will sort that too. This is the lower mounts with the rad out so you can see where the rubber bushes go, it is a straight shot upwards Done! Assembly is the reverse of disassembly, with blood less likely to be shed.
    • Right, onto the second last trick. The Air Con condenser is mounted to the front of the radiator and stays in the car when the radiator is removed. There are 2x 10mm headed self tappers holding the top of the condenser to the radiator, remove those The bottom of the condenser is attached to the radiator with clips. You need to lift the condenser out of those clips and clear (up, then forward). f**ked if  could work out how to do that last bit with the front bumper on. I hope you can, and you share the trick.  Bumper removal probably deserves its own thread one day once I've recovered the will to live, but basically you need to remove the wheels, front inner guard liners (clips and 10mm headed bolts), the self tapper between the guard and the bumper at the rearmost point of the bumper (same as an R32 that bit), any remaining clips at the top/front of the grill, an absolute bastard design with a plate that holds the top of the bumper above the headlight each side (only 1 bolt which is tricky to get to, but the plate catches 2 places on the bumper and must be removed....carefully!) and push clips between the bumper and guard under the headlight. If you've done all that you will be faced with wiring for the fog lights on both sides and in ADM Q50 RS at least, 4 nasty tight plugs on the driver's side for the ADAS stuff. So, the clips at the bottom look like this on drivers side (looking from the front) And on the passenger side (also from the front), you can see this one is already out Clearance on both of these are super tight; the condenser needs to move up but the upper rad support mount prevents that, and the radiator can't move down far because it is (rubber) mounted. Once you achieve the impossible and drop the condenser off those mounts so it does not stop the rad moving, you are good to go
    • OK, next the shroud needs to come off and there are a couple of tricks. Firstly, there is a loom from near the passenger side headlight to the fans, coolant temp sensor etc and there is no plug to undo.  In my case I was OK to leave the shroud on top of the engine so I just undid the passenger side fan plug and about 10 of the clips which gave enough free wire to put it aside. The fan plugs were super tight, the trick I used was a small falt screwdriver to push down on the release tab, then a larger flat screwdriver to lever the plug out of the fan unit....be careful with how much force you apply! If you need to remove the shroud altogether for some reason you will have to deal with all the plugs (tight) and clips (brittle)....good luck. I removed all of the clips and replaced them with cable ties that I will just cut next time. Also, in the Red Sport / 400R at least, the intake heat exchanger reservoir hose is bolted to the shroud in 2 places with 10mm headed bolts; so remove them (the hose stays in the car; no need to undo it at the t fittings down at the radiator lower mount. Once you've dealt with the HX hose and the wiring loom, there are 3x 10mm headed self tappers holding the top of the shroud to the radiator; remove those.   The shroud then lifts out of the bottom mounts where it sits on the radiator, up and onto the engine out of the way. Simples
    • Ok, disregard my “rate them” comment, sorry for my unrealistic input
×
×
  • Create New...