r0ma

Hi All,

I have just picked up my first FD (2001) Type R several days ago.

I am having an intermitent problem with boost (I think boost related anyway).

The car runs awesome! both turbos working fine & very powerful, etc but I went for a spirited drive yesterday then came home, cooled the car down as per usual, I then left the car for around 20 mins then went to drive it: the car would not boost at all! I pulled into a nearby garage and filled fuel up, checked all lines under bonnet and could not see anything obvious. I started the car up drove off and it was back to running perfect! <-- this exact same issue then happened again today.

The symptoms were as follows: If I put my foot down (to the degree of usual positive boost the car will splutter/shudder, have no power & will not accelerate, this happens at any rpm) the boost gauge remains at a neutral reading (will not have any positive boost)

If I apply the gas lightly the car will rev through the range (obviously much slower, but keeping the car so it remains on vacuum)

I am hoping someone will have some suggestions, I plan to buy a vacuum pump and attempt the solinoid test as per the faq, I am not sure if it is a boost issue, maybe limp mode?

Sgtblue

iTrader: (16)

^Yes, sounds like Limp Mode. If vacuum isn't seen at the intake manifold, fuel is cut and timing won't advance. It will start and idle normally, and you can rev to redline as long as you do it slowly and maintain some vacuum. Because timing won't advance, you will have NO power.
As for what's causing it, there should be a way to pull codes on the JDM versions, but they're different in that regard from our LHD cars up here. Check with some local owners/shops. You also have a Aussie based forum FDRX7.com. My bet would be one of the three codes associated with the MOP.

r0ma

thanks mate, yes it doesn't feel like a boost issue, I just was not really aware of how limp mode felt. I will do a bit of investigating.

loosedougie

I have exactly the same problem. Three different garages have looked at it including a Mazda dealer. No one can sort it. Was thinking maybe the ecu might be packing up. But no one will say. To get around it I have to park up for a few minutes before trying again, or disconnect the battery, which seems to sort it for the rest of that trip. Not a fix though.

Sgtblue

iTrader: (16)

I recently searched for someone in the 3rd Gen. Section and came up with this link for checking codes on JDM models (I THINK it's the same for all RHD models)---> https://www.rx7club.com/3rd-gen-arch...ut-ecl-238994/

If you pull a code, go here ---> Check Engine Light Codes and see what you get.

r0ma

I can not find a common pattern either, the first 2 times it was trying to drive the car off after going for a spirited drive, but just now I had been putting along in traffic (no boost or high rpm at all), stopped the car to pickup some parts, jumped in 5 mins later and limp mode.

I just pulled the idler pulley as it was causing a heap of noise, replaced the bearing as it was near seized, I hope that is the source of my ruff idle as the idle would jump around a bit at the same time the pulley would make some strange noises. I am hoping it is all related (but I doubt it).

& yes if leaving the car to rest for 20mins or so would go back to normal.

I will attempt to pull the ecu codes.

r0ma

Ok, I took her for a good drive tonight for a couple hours, hwy and city.

I have found a few things;


Intermittently near the end of the trip, the car would loose boost (not like the previous limp mode as described in the first post) this time the car actually went quite well, just no positive boost. it was running like a normal n/a. but then 5 mins later after cruising it would come good (maybe heat related - messing with a solenoid??)

^^ and when doing this, when you backed off the gas, it would make a very faint whoosh noise (like a bov) but not very loud.

Mrmatt3465

iTrader: (10)

Heat can do some funny things to the solenoids. There are plenty of instances when a solenoid will work fine at ambient temperature and then not at all under the heat of the engine bay. Have the vacuum hoses been replaced? If not that is also a good place to start along with check valves. The hoses get extremely brittle under the heat of the motor and tend to crack and break. Check the hose for your map sensor for cracks and damage as well. It's mounted on the firewall near the throttle body elbow. If you discover your solenoids are shot, then I highly recommend the azeknights rack. It's in the 3rd gen group buy section. The FAQ has a ton of info on the sequential twin turbo system. Read through the theory of operation as well as the troubleshooting and you'll find your problem

Matt

sbinji

i had a skyline gtr n it had a similar issue. sometimes it boosted fine sometimes there was no boost. it would start to hesitate right at 3000rpm under load, unless i accelerated slowly. i could redline it in neutral no problem, similar to what sgtblue said. i found out there was a boost leak, one of the pipes wasnt connected properly.

r0ma

Ok, just an update for anyone interested.....

I found my Charge Control Solenoid was faulty (tested with a multimeter)

The car is now driving much better!

The only issue I have at the moment is when the car is sitting in traffic and gets hot, 1st gear will run only small boost and second turbo doesnt appear to kick in, all ther gears are fine or once the car gets a bit of airflow 1st gear is fine again. has anyone seen this before?

r0ma

I have done a bit more testing..... hooked up a proper boost gauge, put a T-Peice between manifold and stock BOV.

I am seeing the following boost patern: 10-5-10.

When the car does not boost in 1st gear (intermitant problem), I am only seeing 5psi.


Any suggestion? I'm thinking turbo Control Actuator ?

r0ma

Hi All,
Any sugestions on below symptoms;

I am seeing the following boost patern: 10-5-10.

The car sometimes does not boost in 1st gear (intermitant problem), I am only seeing 5psi. so second turbo doesnt kick in.