ECU rev's past 7.5K....n00b question

Crim · 04-10-2004, 08:52 AM

Recently picked up a new car... its a 1992 Classic SE-R.

I really havn't driven the car because no insurance and no tag, however I rev'd the motor up to bounce it off of redline in neutral, and well... it just kept reving past 7.5K.

I did this twice to verify I wasn't on crack.

Does this indictate that the car has a reflashed ECU? Or is there a ghetto mod that elimiated your rev limiter (The previous owner had some serious issues with doing things the ghettofab way)

Crim · 04-10-2004, 08:54 AM

to clearify, when i said it rev's past 7.5k, there appears to be NO rev limiter at all, IE rev as high as you want til you throw rocker arms and blow stuff up

drummer4lifex · 04-10-2004, 10:39 AM

I don't have a rev limiter, then, either. But, I remember once hearing about the early rev limiters were set at like 8250 rpm, which would, then, make sense... but I'm not sure.

eric96ser · 04-10-2004, 10:46 AM

The tach is not acurate up high. Some cars indicate 8000 before the rev limiter kicks in. The earlier cars did nt have the limiter set at 8250. B13s were 7500 and B14s were 7100.

Crim · 04-10-2004, 11:43 AM

hrm... well it hit atleast a tach indicated 9000 (Our tachs show up to 9000 right? In my NX i had the crappy 1.6 digital dash so I don't remember what the SE-R's cluster went to)

I just rev'd it up expecting it to bounce redline, and it burried into the bottom of the cluster.... Good thing its a crap motor thats getting pulled soon.

Will · 04-10-2004, 01:13 PM

damn. that is really really weerd. i have never heard of a de revving that high on its own without a mishift or somthing.

Crim · 04-10-2004, 01:32 PM

I'm hoping its a JWT reflashed ECU w/o a rev limiter...that'd be hot

civicsRslow · 04-10-2004, 01:49 PM

my 91, if i have it in gear it revs to 7750 before the rev. limit hits, but if i miss a gear or free rev it, its 7500... odd

BlkB14 · 04-10-2004, 02:53 PM

Quote:

Originally Posted by Crim

I'm hoping its a JWT reflashed ECU w/o a rev limiter...that'd be hot

Pull the ECU out, JWT should've put their sticker on it...

nizzan4u2nv · 04-10-2004, 03:00 PM

Hmm, maybe the tach is really off. Thats crazy though.

SHAWNATGERBROCK · 04-10-2004, 03:41 PM

Man, I really wouldnt want to do that to much , freerev past 6000 is a quick way to need a new engine, you will have to drive the car to know for sure, but from what I have been told , there is no way to remove the limiter on the SE-R ECU's , You can do it with a 240 SX ECU retuned for your 2.0L , but I may be wrong ... I can say on my 93 Altima the rev limit was 6200 and the tach read 7000 when it hit the limiter , I tried a good tach and it was a solid 6200 , but the stock tach was that far off ...

nj20de · 04-10-2004, 04:15 PM

yeah one way to check this out would be for someone to hookup a techtom or one of the 300degree consult thingies... that will give you the rpm reading from the crank angle sensor which the ecu uses for... well for controlling the engine

Calum · 04-11-2004, 12:02 AM

Just open the top cover of the ecu. If its a JWT ecu there should be a sticker on the outside of the ecu, but JWT isn't the only source of modded ecus. When you open the ecu, if there are two boards inside the ecu has been modified, if theres only one board its still got the stock rom. This is what a JWT ecu looks like, you can see the two circuit boards. The board on the bottom with all the junk on it is the factory board and the big green board on top is the JWT board containing the new rom (it says JWT on it). JWTs board will use a single big rom, the Japanese-based add-on boards use two smaller roms. The factory Nissan add-on boards (these ecus appeared in some European countries) use a bunch of extra stuff and will say JECS on them.

The stock rev limit can be removed. FYI every B13 and HP10 (G20) OBD-I unmodified ecu I've run across has the rev limit at 7500 including auto ecus. Thats not BS, I can dump the rom. Also there is another way of adjusting the stock limit to 10k+, but if you don't have idle issues this has definatley not been done and its seriously ghetto. If you ecu has been modified you can send it to me or drive up to TN some weekend and I'll tell you exactly whats been changed.

drummer4lifex · 04-11-2004, 02:36 AM

Well thats weird... My tach must really be off then. I've revved up to 8250 on my tach and didn't hit a limiter... I didn't do i ever again though. Is there a way to update the tach and make it more accurate?