Engine/Brakes/Capacitors/Rev limits

[owensexport]

Well took the beat on my first high speed drive tonight. After complete engine rebuild and replacing all of the calipers, rotors, brake hoses and spindle bearings, I thought I would tackle the capacitor problem.
Although I was not having any troubles with the short drives I had taken since the motor was fixed, I figured I better get in and fix the caps... boy am I glad!!
One was exploded and fell apart as I unsoldered it.
After about 2 hours messing around with my very dusty electronic
equipment, she was all back together.

I discovered a Feel's speed "Unlimiter" installed next to the ECU.

Took her out on the highway tonight and got her up to about 70 mph and WOW! what a fun car to drive!
It is weird for me as I am a die-hard truck man and I am not used to being that low to the ground, but it is fun to Beat it!!

Questions for the group:
What is the speed limiter set to in the ECU?

I also noticed that I have the 7200 RPM limit mentioned by other posts.... I wil have to drive it some more to see if that bothers me or not, trying to go easy on it until the rings are broken-in....

[Midship]

Another 7200 rev restriction?! This has gotta be the number one beat mystery! i dont know what id do if i didnt have 9000RPM to play with!

Has anyone tried swapping in a known good ECU?

[Steve_M]

Originally posted by Midship
Has anyone tried swapping in a known good ECU?

Yes, no change

[beat boi]

what version beat do yas own

[owensexport]

1991 PP1

[adrianp]

Well me & Steve are still scratching our heads on the rev limit problem...

The thing is, we can't seem to find any info on the problem happening in Japan...!!!

So far on mine (1992 J reg), we have changed...

New Distributor Assy.
New Plugs
New Plug Leads
New Air Filter
New Fuel Filter
New Cylinder Position Sensor (But it did cure an engine fault code...)
Swapped ECU with a known working one
Project A chip tried, (Which should remove rev limiter on car but didn't)

When I get some time, me and steve are going to meet up and start swapping some more bits over to try and solve the problem...

But with work etc, I just haven't had time to think about doing it.

Obviously, if we do cure it, there will be a big anouncement on here telling everyone.

Adrian.

[Adam]

Adrian,.

Was this problem there since you got the car?

At 7200rpm does it cut you off and the revs drop or will it just stop reving, and stay at that?

[adrianp]

Hi Adam,

Yep the rev problem has been there since I got the car although I didn't discover it untill about a week after I bought it... (thanks for telling me mr seller...)

It seems to get to 7250 and then just hold there, it sort of tries to go past, the engine note changes (seems to get louder) but it won't rev any more...

To be honest, it's not really much of a problem as I have learnt when to change gear pretty much by sound / time rather than watching the rev counter but I would guess if/when I come to sell the car then it would be a big minus to potential buyers...

Adrian.

[Adam]

Oh ok, so my next question is to everyone with this problem. Has anybody witnessed this or was this on the car at the time of purchase.

I am just trying to establish is this actually something broken or is this a limiter of some sort that was put in.

[owensexport]

My car does the same thing, hits about 7200 and just
kind of cuts out... sounds like it is droping sparks on
random cylinders.
I mentioned this to my employee (Japanese) who used
to work for Honda in Japan and he thought that the beat
engine was never designed to go up to the 8000+ shown
on the tachometer redline... maybe they just put it that
way to make buyers think they were getting a hi-reving
car!
Since I have had a few days to drive on the highway, I
noticed that about the fastest I can go is 80 mph
downhill. Crusing at 70 mph which is just keeping up with
Los Angeles traffic (when it is flowing!) is about 6500 rpm.
I dont think you want to run much higher than that for
long periods of time.
Back to a previous question, does anyone still have the
original speed limit not bypassed? How fast can you go
without the bypass box?

[Steve_M]

Normal beat speed limiter is 87mph (140 kmh)

HTH

[JGGIB]

[QUOTE]Originally posted by Steve_M
[B]Normal beat speed limiter is 87mph (140 kmh)

get steve to rebuild your enging mine went up to 140km no problem and was still going up then I bottled out. :)

[Adam]

Will it rev if you stay in neutral?

[Paul w]

just 87mph?

Ack, you want to try over 90 with the roof down!

The joy of the project A chip!

PW

[Steve_M]

Originally posted by Adam
Will it rev if you stay in neutral?

I think you will find it wont rev very high, due to the fact of no road speed signal, so the ecu hold s the rev limit down.

[adrianp]

Now there's a thought steve...

Does it take the signal from the same wire as the speedo or would it be a seperate one???

I wonder if a wire has become damaged somehow when the engine was worked on???

I know mine has been worked on as has owensexport's, I wonder if the other problem beats have had engine work done at some stage???

I don't really fancy re-wiring the whole car but I can cope with doing small bits if it means curing the problem...

Ady.

[Steve_M]

Its the same signal that runs the speedo, but if the revs/Map signal are generated it would produce a trouble code for No speed signal (Trouble code 17) as certain criteria would be reached.

I know when I disconnected my speed sensor to see whether or not it would let you go above 140 kmh, it certainly didnt like it and cause it to run very badly indeed, enough to cause it to backfire and finally cut out.

So I dont think thats possibility really

[tinytim]

Lets see if we can get to grips with this one, feel free to chuck in ANYTHING.

The ignition is controled by the ECU sending a signal to the ignitor and the ECU is taking info from what to do that?
Some or all of these?
TDC sensor
Crank angle sensor
Throttle angle sensor
Speed sensor
Cyl sensor (No 1 cyl position)
O2 sensor (lambda sensor I take it)
Electronic Air control valve

But all of these have an associated fault code so if there are no fault codes showing they must be working at least at minimal requirements.

So which of these is likely to meet a limit at high revs?
TDC sensor - NO - on/off switch i assume
Crank angle sensor - maybe - what does it do?
Throttle angle - YES - From what Steve has said about this only being available assembled with the throttle body lets assume this has a critical setting.
Speed sensor - NO - If the speedo works this is working
Cyl sensor - maybe - what does it actually do?
Lambda sensor - Maybe - registering no O2 at high revs and restricting fuel, tends to point at the air filter or possibly the EACV?
EACV - maybe - what does it do

So can we eliminate any of these?

Crank angle
Throttle angle
Cyl position
Lambda/air filter
EACV

[Midship]

First of all very good post Tim, its always good to have strict logical approach to these things...

I personally feel that it’s the MAP (manifold absolute pressure) sensor or the throttle angle sensor, but then again I could be wrong...

Hey Paul.. You should set up a poll or even take bets :D

Oh I think I have a map sensor spare off a Honda today if anyone wants to give it ago!!!!!

[Adam]

The cylinder sensor-

When the engine rotates the sensor will signal that the engine is approaching no.1, allowing the timing of the injection pulse to be determined.

[Adam]

Originally posted by Steve_M


I think you will find it wont rev very high, due to the fact of no road speed signal, so the ecu hold s the rev limit down.

Well I just got into my car and it reved all the way to the end. I stoped at 8500 cause its 11.30pm.:D

[tinytim]

OK lets kill the Cyl sensor if it's only for fuel pulse initiation and add the MAP

Crank angle
Throttle angle
MAP
Lambda/air filter
EACV

What does the MAP actually do, it has 2 fault codes so possibly affects 2 settings.

The 7200 revs seems a bit too clinical to me, like it's a reversion setting or something.
I'll put a fiver on the throttle angle sensor.

[owensexport]

Any of the things you mentioned could be a possibility.
It just seems funny that everone's car tops out at the
same 7200 rpm....
Unless anyone can confirm that their car did better than
7200 rpm and then changed one day, I would think it
is in the programming of the ECU.

By the way, I can get mine to go 85mph:
Towed behind my F450 on the trailer :confused:

[Paul w]

Can we have a quick look at EXACTLY what the limited cars are revving to?

If you all post the precise max revs, looking square on to the dial, it may give us a better idea whats causing this.

Can we hold it at full throttle for a few seconds to see if it wavers?

PW

[tinytim]

Can everyone post what known good exchanges have been done aswell.
Paul, If I remember correctly you've done an ecu swap and the problem persisted? Anything else we can eliminate?

I agree with Owensexport that the ecu is controling the revs but I figure it's limiting them because of a dodgy input. Comments?

A bit more thought on the MAP brought be to the conclusion that the signal from this, the Atmospheric sensor, air temp sensor and Lambda are probably all thrown through a sub routine to extrapolate an output. If so, it's unlikely to be causing the problem but can't be written off yet. Comments?

Paul do you fancy putting this subject in it's own thread and sticking it for a while?

[Midship]

From what ive read and understand

"The MAP sensor is a variable resistor designed to measure the difference in pressure between the intake manifold and the outside atmosphere, this signal can be then be used by the ECU to monitor engine load so that when the engine is under load (or at wide open throttle) the computer can alter spark timing and fuel mixture to improve performance and emissions"

Is it possible that the vacuum pipe connected to the map sensor is not connected properly or is leaking, this might case the engine to think the MAP sensor is working (not showing up a code) but when driving the sensor would send a distorted signal to the ECU thus causing the ECU to change fuel and spark setting leading to the limiter that is being experienced.

It would also seem that this map sensor works in connection with the throttle angle sensor, so if this is the case maybe a incorrrect single for that could upset the whole chain of events.

Any thoughts?

[tinytim]

That makes sense and it fits all the criteria, something to have a look at Ade. I was thinking that this would show up on hard acceleration but that isn't necessaraly so. I might even pop my pipe off and see what happens.

[adrianp]

Well, mine is between 7200 & 7250 but I've been classing it as 7250...

Speed wise, on the speedo (still in kph) I don't reach the 140 mark so it's not getting to 87mph either...

I think me & steve really need to get together and start throwing parts from his spare engine onto mine like he suggested to me a while back.

Although it would be interesting to see what happens tim as long as you don't break anything trying...

Ady.

[tinytim]

Not getting 140! We've got to get this problem sorted out, you're missing so much of what the A chip can do.

[owensexport]

In third gear going down the street, light throttle opening, goes up to 6950 rpm, bury the throttle and gets to 7100 with significant change in engine note, much deeper sound and louder than at partial throttle. Have not seen it go above 7100 now that I am watching close...

Vehicle specs:
New rebuilt engine
Stock ECU with new caps.
Feel's speed "unlimiter"
165/70r/13 tires front and rear on non-original wheels.
Everything else stock.

[tinytim]

interesting post there Owen,
Have you guys checked your exhausts?

Without doubt I get the change in tone when I bury the throttle but it's an exhaust tone not the inlet and it picks up as the engne does.

If the cat has collapsed (or the gubbins in the rear box) you will get back pressure that could restrict engine aspiration. A bit obvious I know, but often the obvious is overlooked.

[Steve_M]

Originally posted by tinytim
Have you guys checked your exhausts?


Been there, Done that. No change!!!!

[tinytim]

You must be pulling your hair out with this one Steve,
What have you NOT done yet, what do you suspect?

[adrianp]

Yep, changed the exhaust...

Got a super free flowing VERY loud one on there now that I imported in from Japan...

Didn't make any difference :suicide:

I think if we change the engine, electrics and shell we might solve it though...:bounce:

[owensexport]

The exhaust is original, 108,000 kms.
Looked it over pretty good when I took out the engine, but aside from surface rust, did not notice anything wrong...

[Marcus]

Hi guys,

Been reading this thread and the engineer in me wants to get the bottom of this...

Seems to me that you guys think it is either the MAP, Lambda or throttle sensors that are to blame. Is anyone with one of the poorly beats friendly with a bloke who has got a rolling road and a wide band lambda sensor?

If the lambda readings are irregular then you could rule out the throttle sensor. If it is irregular then depending on the rpm lamnba caracteristics you maybe able to work out what sensor is biased/broken.

Or as is ususal when i try and solve something like this, it has nothing to do with anything ive thought off!!!

Good luck,

Marcus

[Midship]

Originally posted by Steve_M


I think you will find it wont rev very high, due to the fact of no road speed signal, so the ecu hold s the rev limit down.

Mine seems to rev as normal with the car standing, dose this mean something isnt working?

[Steve_M]

In my previous message I did put 'I think', relavent to the revs when stationary, its obviously not correct, and not owning a Beat now I could not try it, even thou it is quite common for Honda PGM-FI systems not to allow full revs when the vehicle is stationary.

I certainly would like to try a throttle body/sensor on an effected car and just check a few other sensor readings.

As yet I can't understand why there are a few Beats with the same fault, What could fail and cause the same thing, or is it that something has been put back together wrongly if they have been apart?? I wondered if the valve springs were the wrong way round inlet/exhaust and its actually valve bounce???

Why does it make such a loud noise when it hits this limit???

If its a sensor then its with in range, but perhaps not at the right time or are we talking mechanical, so would not cause an engine light fault.

It would certainly be interesting to see a beat on a rolling road so mesurements on various items could be made at 7250 rpm to see whats missing/not rising.

[Paul w]

Ok,

What do we need to have ready to swap?

What sensors, throttle bodies etc?

Steve - Can you post a list of everything that could affect it, against wether its been tried already.
Then we can see who has what bits knocking about.
Maybe then the folks with the problem could all chip in to buy the remaining sensors to finally get to the bottom of this.....

Sound like a plan?

PW

[tinytim]

Sounds like the makings of a good plan to me.
The next bit is who wants the bits where. This is where we got to above,

Crank angle
Throttle angle
MAP
Lambda/air filter
EACV

[Steve_M]

Originally posted by tinytim
Sounds like the makings of a good plan to me.
The next bit is who wants the bits where. This is where we got to above,

Crank angle
Throttle angle
MAP
Lambda/air filter
EACV

Crank angle sensor - been done in distributor

Ive got a throttle body/TPS, it also has EACV valve, but I doult that would be prob.

Ive got an O2 sensor as well

poss Ignitor.

Best bet is for two beats to get together a good and a bad and swap parts until it swaps cars.

[tinytim]

What does the EACV do?

I was thinking about the ignitor, it's a bit of a known weak link as it is. But having seen some vehicles that use a spark cut off to limit reves there is a bit of a givaway indication. The exhaust tends to blow up when the engine gets back within revs! That being said if the valves are sealed properly this may not happen on the Beat.

Ady did you check your MAP hoses, there seem to be a few. Not nearly as simple as 1 hose going to 1 place.

[owensexport]

should I remove the feel's speed unlimiter when I install
the project A chip?

[obiwanwasabe]

Hiya,
On some of the early Toyotas I worked on the top speed limiting came from a signal sent from the speedo head , when you changed the imported 112 mph std clock for the UK model the limitation went, I wonder if this could be a signal sent back from the rev counter on yours! disconnect the rev counter and put a temporary one in and try it!
Nick

[Paul w]

should I remove the feel's speed unlimiter when I install

I would, there is no limit once you have the chip in...no rev limit or speed!

PW

[LawrenceHarding]

According to my calculations 7200 ish rpm equates to 140kph in top gear. Is there any way the road speed signal could be confused with the rpm signal for limiting purposes?

[jurek]

Hi been reading about your problems.
My 1992 babe has no such problem she wil rev to over 9k with easy, in any gear and only cuts our in 5th at 140km.
If any one wants to swap bits from my car to compair no problems.
I dont have a project A chip .