ok 2 months ago I installed my EU on my 96 maxima. Got everything setup and the car runs great. Since then though I've been trying to figure out how to increase the rev limit since I have a MEVI. I got the explanation of how to do so and proceeded to try to increase. In the process of doing this I came to find that I am having great difficulties in doing so. I can't tell you how many things I've tried and how many people I've asked and still no luck. I can get it to go through in 1st gear but after 1st it just get's worse, in 2nd it's really rough and 3rd rarely happens.

One thing, and it may be the biggest thing, I think is contributing to the difficulty in increasing the REV limit is that I'm at an elevation of 4000 ft. and I'm thinking that perhaps my car can't accelerate fast enough to overcome the struggle caused by the fuel cut. Has anyone else at high elevations had a difficult time increasing the rev limit with the EU?

Another thing is that my car redlines at 6350 rpms, and not 6500 rpms. And I thought maybe this could be contributing to the problem. Just to verify that the EU and all it's connections are ok I installed it on my friends 97 maxima and his redlines at the correct spot (i should at some point try to see if I can extend the rev on his car but it just takes time). I pulled out my ECU and installed it in his car and the same problem exists, it only goes to 6350. So I thought maybe I just have a stupid ECU. So I recently bought another 96 SE 5spd ECU and thought my problem would be fixed, but no the same problem. So now I'm thoroughly confused. So my next question is to those with 96 ECUs or 96 maximas - does your car/ecu redline at 6500 rpms (verified by an EU, SAFC, or something that shows a digital reading)?

Does anyone have any suggestions as to what would/could cause the car not to reach the correct rev limit? or is it all in the ECU. The next thing I want to try is put a 97 ECU in my car and see if it has the same problem both the 96 ECU's are having and I also want to see if I can raise the rev limit in my friends car.

I'm just so frustrated at this point. I almost want to just contact JWT and see if I can get them to just increase the REV limit only on the ECU, but I know they would charge me an arm and a leg.

But any help that you may be able to offer would be greatly appreciated.
Thanks

 

I was going to suggest trying a different year ECU, like 95 or 97 but it sounds like you're going to...

Send me your current em2 file please, I want to take a look at a couple things. dvrditar @ hotmail . com

Also, any chance you could take a short video of your tach needle as you're doing a 2nd gear run? Would be interesting to see just how fast/slow it's climbing...

And what happens in neutral, is it smooth going past the limiter?

edit: have you changed anything since the last em2 and log files you sent or can I look at those again (if I still have them)?

 

Can you post a log of you redlining 2nd/3rd?(stock non modified map)

IPW, TPS, RPM, and MAF should be enough on the log. And AF if you have a wideband.

 

To both dandy and kevlo, I don't have the laptop with me right now, but when I get home after work I'll send the em2 file and post a log of 2nd and 3rd (but I don't have a wideband yet, I hope that's ok).

Anyhow for dandy I'll try and take a video of the tach, in 2nd. In neutral the engine flies through the stock rev limit, you wouldn't even know it existed.

 

Actually send me the log file as well as the em2 please, unless nothing's changed since the last time around (see the edit in my first post)

 

Only thing that's changed since last time is I've added like 5 degrees timing advance to see if it would help in acceleration and make it easier to pass through the rev limit, but still no success. I even put my stock wheels back on the car to reduce weight and rotational mass and still no change. The only time it goes through the rev limit easier is if i'm going downhill. On an up note i'm averaging 27.8 miles per gallon.

 

I'm pretty sure my redlines at 6350 (JDM Cefiro 94).. people have comment on my dyno "why didn't he take it to redline" and in the video you can hear him bounce of the limiter

 

Nothing has changed from the EM2 file in anyway. As stated in a previous post, i only advanced timing. File have been sent. I'll work on getting a video of the 2nd gear pull.

 

Can you give me your email address so I can send you the log file. Unless you just want some screen shots of the 2 gears.
If so, let me know where you you want the readings shown at.

 

kevlo2000 at yahoo . com

 

Ok Micah I need to know the version info as I asked in the email because some things aren't showing up right for me, the airflow and vehicle speed don't make sense, but just looking at the logs quickly, I think adding fuel at 6450 is too late. For whatever reason your ECU seems to cut at 6350, so I'd try 6250 or 6300 to start adding the 9.5 ms.

I'll await your response on the version info though before commenting on anything else.

 

I replied to the email. They are v2.00. I didn't know there were updates.

Those files were from when I first installed the EU. So the VS pulse was incorrect but had no bearing on how the car performed. After changing it, that still didn't effect how the car went through the rev limit. As far as the MAF I'm not sure about that, I'll get some new files see if you see any difference. If any setting is incorrect please let me know.

And trust me from our previous discussions we've had, I've tried absolutely every combination possible to extend the rev limit and it only get's to a certain point, and won't get any better.

 

Yeah the VSS won't affect the car performance unless you have the specific map programmed but it makes it easy to tell the gear at a glance on the logs when zoomed in and scrolling around all over the place. It's not a big deal though really.

But yes I'd like to see a current log/EM2 combo, going through the gears 1-3. Watching the video your car gets through 2nd gear a lot higher than what's shown on that log you sent, so it doesn't match up to what seems to be the current situation...

 

I know it's all just weird, what I noticed though is that when the tach reads 6550 rpms the EU is reading 6350ish rpms. And my crazy moving all over the place at the rev limit is due to the terrible lag when the car is trying to go through the rev limit. I keep watching the video and it looks like it goes through the rev limit fairly easy but it doesn't by any means.

 

The tach being 200 rpms off at that high rpm is normal for these cars, but you still get up to at least 7200 on the tach which is say 7000 for real. I can hear a stumble when you go through the limit though, which doesn't surprise me if the engine is being fuel starved for 100 rpms...

 

This is true but when I add the fuel earlier it doesn't seem to make a difference. I've tried adding fuel at 6200, 6250, 6300, 6350, & 6400. And no matter what I do, when the car hits the stock rev limit the revs drop and then the injector duration bounces around like crazy for a second and then moves through - in 1st and 2nd. 3rd, rarely ever works.

But on my lunch I hope to get some new logs with stock rev limit and let you and kevlo look at them. This evening I'll do logs of adding fuel at 6200, 6250, 6300, & 6350. And we'll see that for some reason my car wants to fight me and not function the way I want it to.

 

Alright emails were sent to both Kevlo and dandy. Please let me know what you think. thanks

 

Your log doesnt open right for me. I get all these crazy numbers and every line has a spike so I dunno wassup.

 

Do you have the latest version of the EU?

Also, you'll have to drop the scale down to 20ms instead of the 838 or whatever it is at currently.