25 replies to this topic

[GENONE]

hey all,

im ironing out issues with my gen1, and today the issue is its cutting out at about 3000rpm in every gear... like a rev limiter...

any ideas what could be causing it to do so?

mike

[lambs]

im ironing out issues with my gen1, and today the issue is its cutting out at about 3000rpm in every gear... like a rev limiter...

any ideas what could be causing it to do so?

I don't have much experience with Honda EFI systems, but I'm learning and I have a lot of experience with other makes. Generally what your describing suggests the ECU has gone into some form of limp home mode (esp if it's a hard cut at 3k rpm). Usually that's caused by failure or disconnection of an important sensor (eg AFM or MAP). First thing to check would be ECU error codes. Of course all this assumes the car has an ECU in the first place.....

Other possibilities are collapsed/blocked cat converter or clogged fuel filter.

[icebox187]

yeh sounds like limp mode..... there should also be a cold rev limit, normally couple thousand below redline rev limit...... not sure what your redline is though. probably just wiring problems

[GENONE]

Ok - muchly appreciated guys!

i think you may be onto something... basically the ECU im currently running is a ZC ECU but with a chip for the HKS supercharger. When i run stock ECU there is no code but with this ECU the code shows 13 (APS - atmospheric pressure sensor) - however the car has never been equipped with one...

Could this be the issue? i live pretty much at sea level... guessed it would just run it in stock mode....

I might have to hook up a 5v wire to the ECU to trick it or get one out of a gen2 CRX.

[3GCVC]

speedo cluster,

check it and the board on the back with the over 100 buzzer for all connections and dry joints, the revlimit is triggered from the cluster sounds weird but its happened to many ZC users try banging on your cluster surround when its doing it and it may come right. or try a spare cluster. anyways try it and let us know how it goes...

[strudel]

speedo cluster,

check it and the board on the back with the over 100 buzzer for all connections and dry joints, the revlimit is triggered from the cluster sounds weird but its happened to many ZC users try banging on your cluster surround when its doing it and it may come right. or try a spare cluster. anyways try it and let us know how it goes...

OK, this is news to me. Whats a "over 100 buzzer"?? Is this some Ausi/NZ specialty item so that you don't spin off the roads backwards?

Now as far as the rev limiter being controlled from the cluster comment. That's interesting. Normally I would argue with you that it is not the case and the ECU controls the rev limit. BUT, I happen to have an EDM gauge cluster and it has a little plastic set screw on the RPM gauge. I saw another post about something similar and could not find itanymore. So if you can enlighten us on this aspect I would be glad to hear it.

When I run stock ECU there is no code but with this ECU the code shows 13 (APS - atmospheric pressure sensor) - however the car has never been equipped with one...

Could this be the issue? I live pretty much at sea level... guessed it would just run it in stock mode....

I will give you both the benefit of doubt as you live on the other side of the world. All USDM CRX's have an atmospheric pressure sensor. It is fairly well hidden as it resides high up to the left under the dash on the drivers side. Why they put it there is anyones guess. Just because you live at sea level doesn't mean you couldn't use one. Don't you guys have any hills, er mountains, down under?

Since no code with oem ECU and you get one with the ZC there is a possibility of a wiring issue. Not all ECU's wire up the same way. For that particular problem I would suggest getting wiring diagrams to trace out and see if the pins are in different locations. EG. D16A1 vs D15A3 ECU's, that swap needs extra wiring for it to work.

As far as the rpm cutout I can't help but some of the other suggestions sound plausible. Check the wiring to the ECU as it may be the issue.

[3GCVC]

its JDM and EDM a beeper that "beeps" when you are traveling over the speed of 100km/h possibly 110km/h as that is the speedlimit around here and japan as well.

link to another thread which has info on the speedo cluster revlimit
This is a link

[anjin]

Don't you guys have any hills, er mountains, down under?

You would not believe that one million square miles (thats the western side) could be sooo flat. Most of the time you are well under 1500 feet elevation. To give you an idea, I used to live near a 'Mount Atom'. It was a tall, 200 ft sandhill just up from the beach. Even allowing for Australian humour, it gives you a feel for how flat the place is that we would even think of that name.

[GENONE]

Code 13 is PA Sensor (atmospheric pressure)... im guessing its possible either

a: my gen1 doesn't have an PA Sensor
b: the wiring is different between the ECU's

im pretty sure US/UK/CAN Gen1s has PA Sensors? can anyone confirm in JDM CRX's would as well? maybe my pins are different on the two ECU's?

[strudel]

Since you have two different ECU's all I can suggest is to find the wiring diagrams for the car that each one came from. Follow the schematic for the PA sensor wire on each diagram. If they go to different pin locations that may be your problem. Without diagrams you are in dicey territory.

It may be a totally different problem but this is a place to start. In a normal D16A1 the pinout locations for the PA sensor are:

R1=C9
Br/Bl=C12
Y/R=C13

C12 and C13 have other locations that connect to tthis pin as well. A wiring diagram is your best friend. JS

[GENONE]

yeah, i found the wires... will grab the multi-meter tonight and have a look at what voltages are where.

I popped into a tuning shop thats local to my house, and explained a few issues. they also told me I might want to T off or connect the MAP sensor to the manifold 'AFTER' the supercharger... what you guys think?

[lambs]

they also told me I might want to T off or connect the MAP sensor to the manifold 'AFTER' the supercharger... what you guys think?

MAP sensor needs to be connected to the inlet manifold on the outlet (or pressure side) of the supercharger.

[GENONE]

MAP sensor needs to be connected to the inlet manifold on the outlet (or pressure side) of the supercharger.

cool... thanks...

so just on the pressure (post) supercharger side? not 't' off and run both before and after?

[strudel]

Do you have any pictures you can post of this HKS supercharger setup. I would like to see how it is all hooked up. FWIW, anything I have read about turbos, the MAP sensor has to be fooled somehow but I don't know if that applies to your application. JS

[dirtyass1]

i had four cars do that. a 92 miata, a 96 dodge neon, an 88 shadow, and a 89 ranger. all bad pcm. limp modes a bitch. may sure you pin that WHOLE pcm out...check all pins for what is normally found on them.....or you may miss a wiring problem and waste money on a pcm.

Edited by dirtyass1, 20 February 2008 - 04:53 PM.