[rusEfi] 1995 Honda Accord - auto, vtec (#5)

What engine are you torturing? Is it inside some car?
User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

1995 Honda Accord - auto, vtec (#5)

Post by russian » Thu Jul 17, 2014 3:01 am

1995 4 cylinder SOHC, vtec, OBD-I, distributor
Auto (TCM separate from ECU)
honda_1995_ex.jpg
honda_1995_ex.jpg (102.73 KiB) Viewed 15350 times
The wheels a bit ridiculous, but whatever. Now I need to get plates & figure out the state inspection.

http://rusefi.com/wiki/index.php?title= ... ccord_1995
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Thu Jul 17, 2014 3:16 am

Engine mount control solenoid?!. OMG.

Wow. That's definitely another use-case for http://rusefi.com/forum/viewtopic.php?f=5&t=612
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Thu Jul 17, 2014 6:02 am

may i offer you my congratulations on the new test mule? :D

User avatar
kb1gtt
contributor
contributor
Posts: 3470
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by kb1gtt » Thu Jul 17, 2014 9:42 am

Injector resistors? I see 3 VR sensors, what is the CYP sensor sensing? Is that Crap Your Pants?

Looks like the trans needs to know the TPS. Could it be Toilet Paper Sensor as a match for the CYP sensor :) I would suggest you measure the ECU's impedance and make sure your ECU has the same resistance. Other than that, this looks to be not an issue. I also see the ECT sensor. You should do the same thing with that,make sure your ECU offers the same resistance as the stock ECU.

I wonder why the trans cares about baro pressure. I also see that pressure seems to be reported by the ECU, but the ECU only has one MAP sensor, which is probably not Baro. So this could be a potential problem. You may need to take some measurements to see what this signal is doing. If you simply ignore this signal, I would wager a guess the trans will work but will probably not shift quite as desired.

I've got a solenoid motor mount on my daily driver. When the engine is below 1.7kRPM, it activates to make the mounts softer, which is supposed to make less vibration. I hate that thing as it's in the way when I do the oil. You have many of those motor mounts.

Any how, good news, looks like that auto trans is not a real issue. I wonder how well the pin out works with Frankenso.
Welcome to the friendlier side of internet crazy :)

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Thu Jul 17, 2014 2:25 pm

I bet trans needs baro to see the engine load to make decision wether to shift the gear or not...

blundar
contributor
contributor
Posts: 63
Joined: Tue Jan 07, 2014 4:38 am
Location: Cincinnati, Ohio

Re: 1995 Honda Accord - auto, vtec

Post by blundar » Thu Jul 17, 2014 2:35 pm

Honda's injector supplier (Keihin) didn't have a saturated injector when this was made. Or they had a ton of the older P+H injectors left in inventory. In any case, the resistor box on the injectors serves as a current limiting job to allow the injector drivers (NPN Darlington arrays, 2 inj per array, made by Sanken) to control the injector with <1amp of current. No magic smoke lost.

Engine mount solenoid I know nothing about.

Vtec is an on/off. There is no PWM on this. On the factory ECUs, it is run as a SOURCE output not a SINK. It uses a moderately beefy integrated transistor thing (Allegro/Sanken SK5050 / SI5050 / SI5151) which has a high side switch with a monitor circuit to detect open circuit and short circuit conditions. Feedback provided on one pin of the 5 pin package. The solenoid itself is moderately beefy - it takes a little shy of 2Amps to drive it if I remember correctly. Vtec is NOT variable cam timing - it essentially changes to a different cam profile. The stock ECU has independent fuel and ign tables for vtec and non-vtec operation.

The distributor is an interesting thing... 3 sensors.
CKP - crank position. 24 teeth / cam rotation, evenly spaced
CYP - cam position, 1 "tooth" (looks like a snail shell) fires before #4 cylinder if I remember right
TDC - top dead center, 4 teeth fires at TDC for each cylinder.

It has been *years* (7? 8?) since I looked at the code for the distributor handling. All 3 sensors are used by the factory code. The TDC sensor is used mostly as a firing edge while cranking in order to get the car to start quickly. (Did you notice how fast it starts for a distributor car?) TDC is also involved as a sanity check. CKP pulses checked vs it, etc. These things use an ASIC to do most of the counting of pulses and stuff so a lot of the really nasty timer oriented stuffs is offloaded off the main MCU, which is an OKI 66K variant not found outside Honda ECUs. They're at least functional on stock code to about 10K RPM.

Coming out of the ECUs, Hondas are inverted dwell. Low output is charge on the coil, high output is idle coil. The ign output line is pulled high internally in the ECU by a (?)12k resistor if I remember right. The ignitor module (usually inside the distributor cap) inverts the polarity of the control signal at the coil itself.

I'm not sure about the ECT sensor bias, but I'll email you something.

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Tue Jul 22, 2014 3:10 pm

blundar wrote:The distributor is an interesting thing... 3 sensors.
CKP - crank position. 24 teeth / cam rotation, evenly spaced
CYP - cam position, 1 "tooth" (looks like a snail shell) fires before #4 cylinder if I remember right
TDC - top dead center, 4 teeth fires at TDC for each cylinder.
That's what I got for TDC and CKP while cranking the engine:
Image
Not really evenly spaced. Do you think it's just the way the starter spins it?
Also eventually I would need CYP sensor for real sequential injection in the right cylinder. Ignition should be fine since there's a distributor.
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Tue Jul 22, 2014 5:53 pm

do you know what's the physical pattern of the upper one (at least how many teeth are there?)
if this inconsistency is caused by the way starter works - there might be a problem with starting a motor…

User avatar
kb1gtt
contributor
contributor
Posts: 3470
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by kb1gtt » Tue Jul 22, 2014 9:03 pm

I wonder if the starter slows down due to compression. Perhaps try pulling the plugs to prevent compression, then see if it becomes more consistent.
Welcome to the friendlier side of internet crazy :)

Nobody
Posts: 98
Joined: Wed May 28, 2014 9:12 pm

Re: 1995 Honda Accord - auto, vtec

Post by Nobody » Wed Jul 23, 2014 7:42 pm

Yes normal, it's the compression of engine slowing cranking speed, then once past TDC it will accelerate. 4 cylinder engines have fairly large torque peeks...

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Wed Jul 23, 2014 8:24 pm

what about v8? from my point of view this could pose some challenges for starting the engine. i guess it's definitely not that bad idea - to start the engine using the signal from dizzy and only after the engine is started (i.e crank sensor signal is consistent) - move to the trigger wheel signal.

Nobody
Posts: 98
Joined: Wed May 28, 2014 9:12 pm

Re: 1995 Honda Accord - auto, vtec

Post by Nobody » Sun Jul 27, 2014 7:39 pm

V8 is going to be smoother than the 4-cylinder example that was posted. The 4-cylinder has a compression cycle every 180* (degrees), while V8 every 90*, so less torque ripple. While cranking and before engine starts, I tend to look at compression cycle like a pneumatic spring.

If you want sequential fuel injection, you need to run off of crank wheel and use cam to determine if its an intake or exhaust cycle, this includes starting. Crank decoding is probably one of the most important things that need to be nailed down and given priority to (hardware and software). On a high performance engine less than 1* of advance can be the difference between knock or no knock. At 7500 RPM 1 degree is 22us, 1/10 of a degree 2.2us (0.0000022 second). Think this illustrates why this should have priority, also lets not forget about rounding errors at high RPM, where you want the most precision is where you have the least.

In the past I have chewed up 6 timer/counter hardware channels just on crank decoding. 2 of which were used to convert to angle domain… timer and modulus counter 0-3599 (this was a 2-stroke so 0-359.9*).

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Sun Jul 27, 2014 8:23 pm

Nobody, have you seen the russian's code for crank decoding? Do you think it's good enough for the purpose? BTW, what is the usual procedure to calculate the angle? say, you have a 36/1 trigger wheel, you get the time per 1 tooth, you divide this time into 10 equal pieces and hence you get the angle from the last tooth? does it compensate somehow for the inconsistency of tooth duration during various cycles? does it actually need to compensate for it?

Nobody
Posts: 98
Joined: Wed May 28, 2014 9:12 pm

Re: 1995 Honda Accord - auto, vtec

Post by Nobody » Sun Jul 27, 2014 11:33 pm

How you approach crank decoding is to a large extent is hardware dependent. How many timers/counters, at what resolution (16, 20, 24, 32 bit), the higher the resolution the better the granularity. Also on modes of operation, single/double capture, with/without de-bounce filter…

If you attempt angle then that should be done in hardware, because you would link other functions to it i.e. injectors and spark (ignition coils). On some MPUs you can have a common counter/timer buses to which you would link said functions.

Converting time to angle in hardware, with constant minor corrections can be a timed modulus approach… I updated critical timing twice per crank tooth, but again approach varies and very much MPU dependent. In simplest terms yes you would look at time per tooth and how many degrees that tooth is. You need to know if it is accelerating or decelerating and by what delta and factor that in with smoothing/filtering. This part can be somewhat complex to very complex. Usually you have a high speed timer (in nanoseconds) that increments modulus counter by 0.1 or 1 degree, this timer is constantly being updated and modulus counter corrected incase it is out of sync or error is too large. Ideally you would want at least 50 high speed timer ticks per modulus counter increment at max RPM.

If your engine is running well (no misfire) and all pistons are doing about equal work, then your torque ripple will be consistent and timing repeatable. But if missing then your accel/decel will vary throughout 720* (4-stroke) and decoding require more work/logic.

I really don’t have a good answer for you, as I think this is one of the largest variable in many ECUs. I’ve swapped out ECU to different unit on same engine with no modifications and had it make more power, just because it was more repeatable/accurate…

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Mon Jul 28, 2014 12:55 am

Nobody wrote:How you approach crank decoding is to a large extent is hardware dependent. How many timers/counters, at what resolution (16, 20, 24, 32 bit), the higher the resolution the better the granularity. Also on modes of operation, single/double capture, with/without de-bounce filter…
* rusEfi is implemented based on the idea that with modern 100+ MHz microprocessors the relatively
* undemanding task of internal combustion engine control could be implemented in a high-level, processor-independent
* (to some extent) manner. Thus the key concepts of rusEfi: dependency on high-level hardware abstraction layer, software-based PWM etc.
There is a brief hi-level description of trigger decoding @ http://rusefi.com/docs/html/
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

Nobody
Posts: 98
Joined: Wed May 28, 2014 9:12 pm

Re: 1995 Honda Accord - auto, vtec

Post by Nobody » Mon Jul 28, 2014 3:07 am

russian wrote:
Nobody wrote:How you approach crank decoding is to a large extent is hardware dependent. How many timers/counters, at what resolution (16, 20, 24, 32 bit), the higher the resolution the better the granularity. Also on modes of operation, single/double capture, with/without de-bounce filter…
* rusEfi is implemented based on the idea that with modern 100+ MHz microprocessors the relatively
* undemanding task of internal combustion engine control could be implemented in a high-level, processor-independent
* (to some extent) manner. Thus the key concepts of rusEfi: dependency on high-level hardware abstraction layer, software-based PWM etc.
There is a brief hi-level description of trigger decoding @ http://rusefi.com/docs/html/
If I dragged this off topic then sorry…

Image

Here is what I was referring to as torque for V8. These torque peaks and valleys are dampened to some extent by mass of drivetrain/flywheel and springs in clutch or torque converter fluid coupling. Now picture a fouled spark plug that intermittently fires, there will be a timing shift/skew that will throw subsequent cylinders off if using a global timer for all scheduling (based on complete revolution). An internal combustion engine is not a constant speed device (deg/sec - angular velocity) but always accelerating and decelerating (worst at low RPM).

Understand your approach, but I guess I design for best possible accuracy. I wish OEMs would put encoder like on servo motors, just about every modern 32bit MPU can decode that in hardware… Nissan 300Z had that.

NOTE - Most if not all use crank as master reference and cam to determine intake or exhaust cycle. Some ECUs will run fine with loss of cam sensor, they use MAP as backup reference to determine intake of exhaust stroke.

EDIT ADDING MORE DETAIL BELOW

Image

Image

Image

Image

User avatar
rus084
contributor
contributor
Posts: 678
Joined: Sun Dec 01, 2013 1:40 pm
Location: Russia , Stavropol
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by rus084 » Mon Jul 28, 2014 7:17 am

Nobody wrote: Image
oh, very large ripple (2000%), this is probably bad ...
I thought that the 4-cylinder engine is balanced, and it turned out that you need at least 8 cylinders to the engine does not slow down sometimes

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Thu Jul 31, 2014 12:12 am

One step forward: I've sniffed the 12V ignition module control signal

Image

Two steps backwards: the car does not start, looks like no spark, I cannot remove three of the four spark plugs! See http://honda-tech.com/showthread.php?t=3217244
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Thu Jul 31, 2014 6:29 am

were they welded in?
what could be the cause for no spark? no signal? wet plugs?
what are the first three graphs? the top one - cps? how many teeth are there?

puff
contributor
contributor
Posts: 2733
Joined: Mon Nov 11, 2013 11:28 am
Location: Moskau

Re: 1995 Honda Accord - auto, vtec

Post by puff » Thu Jul 31, 2014 6:52 am

how does the 'no spark' diagnosis explains that the engine finally starts? I'd say that sounds more like the lack of fuel...
probably it's silly, but i'd say that it's easier to check for spark of no-spark with a timing gun (with capacitance/induction sensor?) at least you'd know that the dizzy is delivering HV to each plug.

p.s. this diagram looks pretty much complicated Image
what are the yel/grn and yel/blck wires?

PPS channel 5 & 6 on your screenshot seem to be almost the same?

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Thu Jul 31, 2014 11:11 am

puff wrote:were they welded in?
what could be the cause for no spark? no signal? wet plugs?
what are the first three graphs? the top one - cps? how many teeth are there?
This morning I've removed #4 plug and I am making good progress on #2 plug. I am not getting it - they look pretty fresh, why would they be stuck there? I guess I should apply some unit-seize.

So far the plugs I've removed are gapped right - they should be 0.039-0.041in and they are more or less that.

Could be weak/dead ignition coil. Could be weak/dead igniter.

A lot of info @ http://rusefi.com/wiki/index.php?title= ... ccord_1995 to answer some of your questions
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Thu Jul 31, 2014 12:32 pm

The book has coil testing procedure (measuring two resistances) - test passed, the coil is fine. Changed two plugs - this did not help, will attach the other two plugs with more leverage later.

There is no ICM test procedure in the book. Should I just check that coil input gets some voltage while cranking? Would that be a test of the ICM? Is that safe?
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

Nobody
Posts: 98
Joined: Wed May 28, 2014 9:12 pm

Re: 1995 Honda Accord - auto, vtec

Post by Nobody » Thu Jul 31, 2014 3:59 pm

Given the year, it likely has engine bay fuel pressure regulator. If it does, pull off vacuum reference line and check for fuel, if any is present then diaphragm is torn (try this after cranking). Long cranks can often be fuel pressure related.

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Fri Aug 01, 2014 10:19 pm

Welcome to my luck: it was the ignition control module I guess. $50 for a used dizzy and this POS starts now!
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Tue Aug 05, 2014 2:28 am

That ~40Hz noise is gone if I disconnect the TCM plug A. The +5 ref line looks clean on the scope, this makes me ask if one of the TCM lines is a digital signal? Who knows... For now I'll just have the TCM plug A disconnected :)

http://rusefi.com/wiki/index.php?title= ... ccord_1995
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Thu Aug 07, 2014 12:12 pm

[video][/video]
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

sturovo
donator
donator
Posts: 32
Joined: Mon Feb 10, 2014 7:44 pm

Re: 1995 Honda Accord - auto, vtec

Post by sturovo » Thu Aug 07, 2014 8:48 pm

Great work Andrey!

User avatar
russian
Site Admin
Posts: 9693
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by russian » Thu Aug 07, 2014 9:14 pm

More like "great work Jared" - that's his design :)
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
kb1gtt
contributor
contributor
Posts: 3470
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: 1995 Honda Accord - auto, vtec

Post by kb1gtt » Thu Aug 07, 2014 10:06 pm

Thanks for the pat on the back. Lots of work put in by many people. It's a collaborative effort. Many people had a hand in making this stuff go.
Welcome to the friendlier side of internet crazy :)

User avatar
Tambralinga
donator
donator
Posts: 174
Joined: Wed Jun 18, 2014 8:36 am
Location: Bangkok, Thailand

Re: 1995 Honda Accord - auto, vtec

Post by Tambralinga » Fri Aug 08, 2014 6:30 am

This model engin F22 or H22 ?
Skype : shiva-p
+66 8 5357 5159

Post Reply