Jump to content
SAU Community

Recommended Posts

Just looking for ideas, my car is not making the power it should be and hesitates at higher rpm when full boost hits. I have a hi flow turbo and thought this could be causing a boost cut but its only hitting 13psi max and was doing it with the std turbo at 10psi as well. The afm meter has been replaced and spark plugs changed.

im thinking that it could be a knackered fuel pump or maybe a coil pack?? any help would be appreciated

Link to comment
https://www.sau.com.au/forums/topic/19117-rb20det-breaking-down-at-rpm/
Share on other sites

Similar problem to what im having at the moment. Ive also changed plugs, fuel filter, put a front mount on, and today i tested another computer, and setup an oil pressure guage to measure my fuel pressure and was also fine. The only things it points to now are one of the sensors is faulty, read this thread and do the diagnostics and see how it comes back, im guessing its a crank angle or knock sensor playing games :)

http://www.skylinesaustralia.com/forums/sh...&threadid=19018

Let me know how it goes, im doing mine tomorrow night :)

cant find that link dude?

did the fuel filter today, getting a new fuel pump soon but have to put that on hold because the car has started making the same sound it did when the old turbo was dying :) (a high pitched scream/squeel) im hoping its a gasket, only one left is manifold to head, changing it tomorrow fingers crossed. had nothing but bad luck thus far

let me know how you go with that cheers

That link is there, but it was under the topic Auto RB20 ecu on a manual or something like that by me. I did the diagnostics and it came back with a faulty knock sensor which would make sense why my performance on my car is poor. Have you found that after 5500rpm it looses a noticable bit of power?

The hesitation at high rpm is probably due to an over rich mixture and this seems to be a common problem with these engines. We found that at around 10-12psi mixture strengths of 10:1 are not uncommon and this causes the engine to flutter at high rpm and causes a noticable decrease in power, ideal A/F should be about 11.8:1 to 12:1. Re gap your plugs to .75mm,we have found that NGK BCPR6Es11 plugs to be about the best.It probably wont be a coil as this is generally indicated by a droped cylinder at idle speed not a high rpm miss.

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

    • Next, remove the upper and lower radiator hoses, both are held with a spring clamp. While you are under there, tackle the Auto Trans cooler lines.  Again both are held on with spring clamps, and as mentioned above you should cap them on the radiator side with an 8mm cap, and on the car side loop them with a length of 8mm pipe - this will stop you losing a dangerous amount of AT fluid during the rest of the job If you've been meaning to add a sender for AT trans temp, this is a great time to do it; put a sender fitting into the passenger side line as that is the inlet to the cooler/radiator.
    • Next you need to remove the intake duct (as with pretty much every job on these cars), it is a series of clips you gently remove with a flat bladed screwdriver. They do get brittle with time and can break, and I have not found a decent quality aftermarket one that fits (they are all too soft or flimsy and don't last either) but the nissan ones are a couple of bucks each (ouch).  Once the clips are off (either 8 or 10, I didn't check) you lift the intake duct out and will see the reservoirs Undo the line into the radiator side cap (some bent needle nosed piers are awesome for spring clamps) and then remove the 4x 10m nuts that hold both in place.  I didn't get these pics, but remove the line under the radiator reservoir (spring clamp again) then remove that reservoir. Then you can get at the intake reservoir, same thing, spring clamp underneath then remove it. BTW This is a great time to put in a larger (+70%) combined reservoir that AMS makes..... https://www.amsperformance.com/product/q50-q60-red-alpha-coolant-expansion-tank/ They also make an Infiniti branded and part# version if that is your thing
    • To drain the Intake Heat Exchanger, there is a crappy drain plug in front of the driver's side front tyre: You should use the largest headed phillips screwdriver you had, and in my case I needed vice grips on the hose above as the plug was tight (tighter than it needed to be, since it has an o-ring seal).  After you have a tray down and open the drain, open the intake heat exchanger reservoir cap (drivers side one) and you should get a couple of litres of coolant To get to the radiator, you need to remove the plastic engine undertray. It is held on with a series of 10mm headed bolts and some clips. For the radiator, there is another type of crappy drain (kind of like a plastic banjo bolt) and you should attach a length of hose to direct the stream of coolant per this pic (otherwise the coolant hits the rad support and goes everywhere). The drain is on the rear of the radiator on the driver's side and a bit hard to find. Put a big tray or bucket down (5l won't be enough) and slowly unscrew the fitting by hand. You only want to remove it far enough for coolant to flow, it you unscrew it right out the whole fitting and direction pipe will come off and you will get a coolant bath (yum!). Undo the radiator reservoir cap and it should empty about 8l
    • So, this shouldn't be such a mission, but there were a few tricks so I thought I'd post up a DIY for it. This was on a Q50 Red Sport but I doubt any other V37 model is very different (maybe just less steps for the intake heat exchanger hoses) I pulled the radiator out to flush it because the car was running hot at the track, but obviously the same steps apply for changing a radiator for any reason including an upgrade. If you are removing the radiator, you of course need to drain and refill, so have 5+ litres of blue coolant ready. You also need to drain the intake heat exchanger to remove the radiator so you will need a couple of litres for that as well. You will also need something to deal with the auto transmission lines, I used 2x 8mm rubber caps on the radiator side, and a short length of 8mm pipe on the car side.....unless you can block these lines quickly you will loose AT fluid and it may be enough to hurt the transmission if you don't refill it. 2 other tools that really help dealing with coolant lines and spring clamps are Bent Needle Nose pliers Hose pliers Between them they will reduce the frustration (and injury) potential by about 1000% Other than that....lets go... "First, jack up your car". Yes really, and put it safely on stands. If you are not confident doing that you need to give this job to a mechanic
    • If the forester is anything like our old 2007 GTB Liberty, I could near on run ling Long's and "rate them", as no matter what, it just hung to the road, even when abusing it in a hard launch in the wet, or throwing it at corners.
×
×
  • Create New...