Rb25 Series 2 Rich With Stock Ecu Lean With Standalone

[95_240]

Here is a previous thread I had that may or may not contain useful information. http://www.skylinesaustralia.com/forums/topic/397420-rb25-problems/

I did run a Nistune ecu for awhile and it ran smooth but still ran rich and didn't feel like it had much power. I ended up getting an Adaptronic and ditched the Nistune.

Details first. Compression test was fine, boost leak tested and fixed leaks, maf was changed out with a working one, tps is new, new coilpacks and plugs, freddy intake manifold, q45 throttle body, and everything else is pretty much stock. I have also replaced the injector seals and tested the rail for any leaks.

Now with the stock ecu my vacuum is at 20, idle is around 900, and the afrs are about 14-15 before I do anything. It actually idles smooth on startup but as soon as I rev it up a little it stumbles then smooths out some but the afrs stay around 12-13 after I let off the gas. Every once in a while it will stall after doing this. I haven't been able to take it out for a drive since I fixed the boost leaks but I have a feeling it will drive like it did before. Then it would surge and buck really bad throughout the rpms regardless of boost.

The standalone I'm using is Adaptronics e420d. It has a map sensor that I'm using. When it is at idle the vacuum is at 14 and it idles like crap. The afrs are about 16-18 and most of the time when I rev it the engine stalls. Even though it has lean readings it smells very rich. I don't know if this is normal with the batch firing and wasted spark. Maybe it is misfiring causing the low vacuum? I still believe the problem exists somewhere else as I am having problems with the stock ecu.

I have talked to a couple of shops near me that are supposed to be experts with rb25's but their solutions are to use the standalone to tune out any problems. I believe that I should get it running correctly before using the standalone to tune it. I'm looking for any help you can provide.

Thanks

[Rolls]

What maf are you running? sounds like you've changed a lot of things, have you hooked up the FPR to a vac signal correctly, is the fuel pump working? do you have correct fuel pressure? Have you done an intake smoke pressure test to check for leaks? On vac this will make the car run lean, will go rich when on boost.

If you are getting misfires the lambda reading won't be accurate so you need to fix these before you can rely on it, when you hit the limiter on full load I've seen the afr go lean but it was blowing black smoke.

edit: if it is missing the idle vac will be crap, you won't get full vacuum as half the cylinders aren't firing so you won't be getting as much air drawn in, hence less vac, this is a symptom of missing, not a cause, though if you have an air leak it could be a cause. Don't get it tuned until they fix these issues, tuning around issues like this is just a bandaid and not fixing them, it won't make the power it should either if there are leaks etc as well.

Edited January 28, 2013 by Rolls

[95_240]

Still running the stock maf on the stock ecu. The fpr is set to 43.5 psi. I have pressure tested the entire intake system and there aren't any leaks. I'm thinking that there might be a misfire but I'm not sure what could be causing it. Thanks for the clarification on the misfire and vacuum. I was wondering what would actually cause the vacuum to read low.

Edited January 28, 2013 by 95_240

[AngryRB]

Here is a previous thread I had that may or may not contain useful information. http://www.skylinesa...-rb25-problems/

I did run a Nistune ecu for awhile and it ran smooth but still ran rich and didn't feel like it had much power. I ended up getting an Adaptronic and ditched the Nistune.

Details first. Compression test was fine, boost leak tested and fixed leaks, maf was changed out with a working one, tps is new, new coilpacks and plugs, freddy intake manifold, q45 throttle body, and everything else is pretty much stock. I have also replaced the injector seals and tested the rail for any leaks.

Now with the stock ecu my vacuum is at 20, idle is around 900, and the afrs are about 14-15 before I do anything. It actually idles smooth on startup but as soon as I rev it up a little it stumbles then smooths out some but the afrs stay around 12-13 after I let off the gas. Every once in a while it will stall after doing this. I haven't been able to take it out for a drive since I fixed the boost leaks but I have a feeling it will drive like it did before. Then it would surge and buck really bad throughout the rpms regardless of boost.

The standalone I'm using is Adaptronics e420d. It has a map sensor that I'm using. When it is at idle the vacuum is at 14 and it idles like crap. The afrs are about 16-18 and most of the time when I rev it the engine stalls. Even though it has lean readings it smells very rich. I don't know if this is normal with the batch firing and wasted spark. Maybe it is misfiring causing the low vacuum? I still believe the problem exists somewhere else as I am having problems with the stock ecu.

I have talked to a couple of shops near me that are supposed to be experts with rb25's but their solutions are to use the standalone to tune out any problems. I believe that I should get it running correctly before using the standalone to tune it. I'm looking for any help you can provide.

Thanks

so are you trying to run a stock computer with a Q45 throttle and aftermarket intake manifold? i didnt think that could be done without a tune..

would the engine not be getting too much air at idle if not tuned for that throttle body?

In my experiences with my own car, i had a blown intake manifold gasket which caused alot of lean running on idle and mega rich on boost, sounds like it needs a proper tune for all the recent mods.

[95_240]

Plenty of people run the manifold and throttle body with stock ecu's. The engine still draws in the same amount of air. They may lose some power from its design but they don't have any problems with the way it runs.

Edited January 28, 2013 by 95_240

[89CAL]

Plenty of people run the manifold and throttle body with stock ecu's. The engine still draws in the same amount of air. They may lose some power from its design but they don't have any problems with the way it runs.

Not necessarily. 25 ecu's are sensitive to changes sometimes. Have seen some run fine and some not run at all.

Can you get a consult off someone to check for faults. If you think there is a fault this is the quickest way to find it

[GTSBoy]

Main throttle should be 0% open at idle and pretty much all idle air flowing through IAC/AAC valve. So Q45 throttle shouldn't matter so long as it is set up properly. ECU will still want to see the TPS at the correct voltage for idle (about 0.45V) otherwise all sorts of things go wrong.

Are you sure the Freddy is straight? Leak at the flange gasket would not be surprising (seeing as most people assume that they will leak there, based on the thousands that have). I know you did smoke test, but just double checking.

[95_240]

I just did a boost leak test again and noticed air escaping from the valve cover breathers and the dipstick. I deleted the pcv and have the valve covers running to a catch can. So the only way I guess I can get positive crankcase pressure is blowby past the rings. I just used the leak down tester I have and it was showing about 50% leakage across all cylinders. I didn't warm up the engine which could lower the leakage and I was using a harbor freightcheap tool so it may not be accurate. But when I was testing there was plenty of air coming out the dipstick. So I guess every cylinder may have bad rings unless they are supposed to leak that bad when the motor is cold.

[Rolls]

Why did you get rid of the PCV? How is your catch can plumbed up? Sounds like there is your issue right there, probably pressurising the crank case, will f**k your rings eventually if you don't fix that.

[95_240]

I have both lines running to the catch can with a breather filter on the can. In this setup the gases can still escape without pressurizing the system.

[Rolls]

So the PCV is removed and you have a line going to a venting catch can acting as an air leak? Or you have the PCV with a line going to the catch can?

[rob82]

Main throttle should be 0% open at idle and pretty much all idle air flowing through IAC/AAC valve. So Q45 throttle shouldn't matter so long as it is set up properly. ECU will still want to see the TPS at the correct voltage for idle (about 0.45V) otherwise all sorts of things go wrong.

Are you sure the Freddy is straight? Leak at the flange gasket would not be surprising (seeing as most people assume that they will leak there, based on the thousands that have). I know you did smoke test, but just double checking.

The throttle should be open enough so that the iac is doing very little at a hot idle, not all the work.

It sounds like you have an injector leak - did you use any oil on the injector seals when you put them back in?

Edited January 30, 2013 by rob82

[GTSBoy]

Still means the main throttle is effectively completely closed.

[STATUS]

sounds like it just needs a decent tune....std ecu rb25 is looking for a bleed (yes they bleed at idle.. that little hole on std bov) from the bov at idle too dont forget. plus you no doubt are not running plumb back etc with a bigger TB it all leads to a freaked out ecu... log your afm voltage and i bet it bounces around when you let off the gas etc.. I see 10-20 odd rb's a week and it will not run like std with the mods you have.

Refit adaptronic get it tuned properly. std map in them is crap. If youve been chasing this same problem since april last year and still haven't had it tuned.... your nuts.... a few hours on a dyno will have it cherry.

[95_240]

So the PCV is removed and you have a line going to a venting catch can acting as an air leak? Or you have the PCV with a line going to the catch can?

The intake and valve covers are plugged where the pcv valve goes. The two hoses on the top run to a vented catch can.

My compression is as follows:

1 - 180

2 - 180

3 - 160

4 - 180

5 - 160

6 - 180

This is with the engine cold and readings in psi. These are the sames results I had before and when I warmed the engine the 160's were about 170 and the rest were the same. I have also done a leak test with a cheap tester. At first it was showing 50% leakage on all cylinders but after some tweaking to the tool it reads 11-15% leakage. Everytime I test there is a little air coming out the dipstick. Is it normal for the rings to leak a little air?

I did warm the car up for the leakdown test with the stock ecu and the plugs actually had a brown color to them for the first time. Before they were always black from running rich.

I just got the adaptronic from a friend and before I spend money to tune it (dyno time is expensive here and no one has tuned an adaptronic in this area so I figured I will be paying extra for that) I want to make sure nothing else is wrong. I think even with my upgrades it should run better than it is. It would hesitate very bad when I had the stock ecu on before and was undriveable. It does seem to idle better than it did last time so after I double check everything and button it back up I will take it for a test drive.

Edited January 31, 2013 by 95_240

[blind_elk]

The intake and valve covers are plugged where the pcv valve goes. The two hoses on the top run to a vented catch can.

What about the hose from the ex cover down to the (intake side of) turbo?

[95_240]

That is plugged as well.

It's like figure 2 in this image.

[95_240]

I'm not sure what I did but my car is running better but there is still a problem. It ran very well when it was cold and idled good as well. I drove it for about 15 minutes and it was up to operating temperature after about 5 minutes. This whole time it ran well and idled fine. However, when driving on the highway it had a slight hesitation and every time I stopped to idle it would die. When I would start it the only way to keep it running is to hold the throttle down. The hesitation progressively got worse and the idle was still messed up. I unscrewed the iacv screw almost all the way. This got me to 600 rpms but the idle would surge up and down and then even out and then it would eventually surge again. I am replacing the coolant temp sensor because I had a new one around and I'm going to replace the O2 sensor just because I haven't replaced it yet. Do you think one of these two items could have been my problem or do you think it is something else?

Thanks

[95_240]

Just did a boost leak test and it is leaking from the injectors. Since I have a crappy freddy the injectors never quite lined up and every time I installed the fuel rail I had to use the bolts to pull the rail into place. I guess after enough uninstalling and installing the threads were weakened. When I hit boost one of the bolts was ripped from the manifold unseating the first few injectors. So I'm going to helicoil temporarily but then it will be probably be a custom made intake manifold. Has anyone had any experience with building their own manifold and if so do you have any tips?

Thanks