Jump to content
SAU Community

Recommended Posts

Hey i have a R33 Rb25det that when driving threw gears its just not reving out,

it may have been a non turbo converted to a turbo in the past?

its just going up to about 5,500rpm till she seems like it dont wanna go further, sounds like its detting?

stock ecu.?

mods are front mount, custom plenum, pod filter.

What do you mean, when it gets to 5500rpm it doesn't want to go no furthur? It physically stops revving at that rpm or it continues to rev but slower?

Also you say it sounds like its "detting", im assuming you mean detonation however it won't be detonation, few people actually know what detonation sounds like and if you can audibly hear it than it is too late. However with your modifcations on a stock ECU it will be running rich so the chances of it detonating are slim.

I'm going to assume that you are hearing the engine missfire after 5500rpm which is causing it to not want to rev past 5500rpm and causing it to lose all power and drive like crap. What spark plugs are in the car and when did you last change them? You seem to have a common skyline missfire issue. Start searching for "missfire" "coilpacks" "spark plugs" and you will see how common it is.

Edited by PM-R33

Yep that is missfire. It means the spark can not ingnite the mixture in the cylinder due to a poor spark, usually caused by fouled plugs, too big of a gap or a weak ignition system. Change the plugs and see if it fixes it. Most likely it will, if not than you will most likely have to start looking at coil packs.

What spark plugs are you putting into it?

Edited by PM-R33

Also add to the fact the ole - factory ECU.

You've changed the intake properties of the motor via plenum and FMIC.

I dare say increased boost as well.

Couple that with old plugs as you've said... come's as little surprise its running like a bag of shit.

You'll also probably find once you change the plugs - it'll do the same thing again in 1,000km's due to the plugs getting fouled up again.

Moral to the story? Go get a tune!

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

    • Sounds like you've got an interesting adventure ahead here with local support if you have trouble! My guess is that, unboosted, you will be OK with a small upgrade like -9. What will happen is that once the stock ECU sees more airflow than it expects it will add a heap of fuel and pull a heap of timing to be safe because it can't understand how it could get that much air without there being an issue. You will see clouds of black smoke and it won't pull hard through the midrange and top end. So, overall it will be a bit frustrating but should be OK. If you are still nervous set the base timing back 2o through the CAS, but it will be even more sluggish everywhere. As said above through...this is not my guarantee your engine won't be blown into a million pieces, leaving you looking for very hard to find parts A better idea is get a computer with logging ASAP, wire in a wide band O2 sensor and a use remote tuner. I've done multiple cars this way and while it is not as good as a specific tune on a dyno they can get it 90% right. I'd suggest if you can afford an R33 GTR these days you can afford an ECU and tune. And if you can't afford that you sure won't be able to afford the rebuild if it goes bad in the meantime,.  
    • Yeah it would be nice if someone took the time to put that sort of information together, but there are a lot of variations in looms. I think you are making this way hard for yourself if you just want to get it running....sourcing an SR20 with the right wiring will be a billion times easier than matching the RB loom to an S15 chassis. If you do end up going this way, you just need to trace every wire in the loom with a multimeter, 95% of them will go to a location you can confirm at the ECU.....and then post it up for the next person who needs it  
    • Just top it up with water, and keep a general idea of how much you added. It is normal for water to be pushed into and pulled out of the reservoir through the cap, and it should not be more than half full or it will be likely to overflow when hot. Any decent mechanic can do a pressure test of the cooling system to confirm if you have a leak. Keep in mind if it is only leaking a little and when hot it may well evaporate before you see it hit the ground
    • I'd ask the shop what they used and use that. Mixing coolants is sometimes OK, sometimes not, and you have know the details of each coolant to know whether it's a good idea or not.
    • Is it alright to top up with just another green coolant?
×
×
  • Create New...