k24a2 vvt

[Barton]

Hello, A few weeks ago I (with james' help) started a k24a2 engine from acura TSX, but the vvt angle 1 does not behave as it should, this engine has a vvt wheel at the intake cam, but the reference comes from a fixed cam gear from exhaust cam, so I'm using the exhaust cam trigger as a cam sensor, and the intake cam trigger as the vvt feedback.

vvt1 angle spikes I know you'll agree that this is not ok, but by the other hand I'd like to know if that angle should be at any value different from 0.

this is the car:


vvt behavior: http://www.youtube.com/watch?v=5qZyWbH8lik

[Barton]

I was doing a composite log if you needed to have, but I see there is a sync loss when the engine just starts and i try to revv it up, I pull out the gas for a few seconds then try again it works perfectly.

by the other hand, the engine only starts on wasted cop (and runs great), if I select Coil on plug it will never start and makes a lot of backfires, I cheked everything I can think of I need your opinnion.

the timing is ok in wasted cop or coil on plug mode.
tested the spark and fuel secuence, they are ok.
the engine can hit 8k rpm without any problem.
I do not know what else to do

[cukali]

add 180 degrees to cam angle if your working on wasted and not on COP.

I have 4 K series motors. One I run on AEM EMS4 and MS3, one runs on only Hondata, and the other two are built and on the shop floor.

Honda uses the exhaust cam sensor for timing and the intake sensor for VTC angle measurement. For simplicity, I have made an intake cam angle sensor with only one tooth (ground off the other three) and used it with a dial back timing light to get my cam angle measurements. I just unplugged the VTC selenoid and put the timing light on the crank and dialed it until it said the cam was at 0 degrees. Then added PWM to the VTC selenoid until it began to move. Keep your engine above 1500rpms when doing this. I noted the PWM% it took to move the cam to 10, 20, 30, 40, and 50 degrees...its a very small window of about 10% pwm from around 12-22. You only need to use 0-30 and it mostly runs at 30 degrees for cruising and 0 for idle. Under high rpms you will (non turbo under VTEC) 30-50 degrees.

Now, I do not use closed loop for it but I am sure you can buy connecting the intake modified single tooth cam sensor to MS3 and use it that way.


As for those saying the VTC is slow, thats only a mattter of opinion and certainly not why they have 12 individual tables for VTC timing. That is so it can interpolate any fuel pulse and spark timing at any angle and any load at all times making it very accurate and fast...oposite of what people claim. It takes 0.5 seconds to move from 0 to 50 degrees (full range) and the engine can only from rev to redline in 1+ seconds....so, in perspective, the cam can move from 0-50 and back to 0 in less time it takes the engine to go to redline. I have a video of the cam response time someplace I will post it...or make another. The engine NEVER sees a 0-50 range in cam during driving. The most it goes (if its tuned properly) is between 30-50 under high rpms during VTEC or 0-30 under lighter loads lower RPMS...so at most youll need 0.2 seconds to get to target angle....much MUCH less than it takes to free rev the engine. The loss of powerand fuel economy by not using the VTC ability is huge. Sorry for those not able to understand its function and capabilities.

[cukali]

Oh, BTW, that spike is not the cam itself moving, but the sensor or the ECU.

Did you remove all but one tooth on the cam sensor? (intake cam)
Is the camshaft phased correctly? This would cause it not to work in COP mode which sounds like your problem.
Are the wires from the intake cam shielded?

IMO it looks as though the tooth count is not correct between the crank and the cam....it thinks the cam is 0 then 180 then 0 repeatedly.

[Barton]

Hello cukali, I'm using Honda TSX/D17 code (I have a k24a2 engine from a tsx). the engine starts an runs great but only in wasted cop mode, if I go to full COP mode I can see with the strobe light (when cranking) that the 0 at the tuner studio matches the 0 at the crank pulley but the engine won't start no matter what.

btw the spike at the vtc angle, should not be there, because I'm using the code exactly for this engine I'm waiting for help with the code.

[tutuur]

Good to read there are people experimenting MS on K engines, i'm going to swap a K engine in my car and want it to run Megasquirt

[Barton]

There are a few problems left to be as perfect like with other engines

[Barton]

please I would like to have some help

[Peter Florance]

please I would like to have some help

datalog?
msq?

[Barton]

i don't know why the are not in the second post.

[cukali]

Hello cukali, I'm using Honda TSX/D17 code (I have a k24a2 engine from a tsx). the engine starts an runs great but only in wasted cop mode, if I go to full COP mode I can see with the strobe light (when cranking) that the 0 at the tuner studio matches the 0 at the crank pulley but the engine won't start no matter what.

btw the spike at the vtc angle, should not be there, because I'm using the code exactly for this engine I'm waiting for help with the code.

Not 100% positive but I dont believe the TSX/D17 code allows for the VTC measurements. Its only for crank and cam inputs. I couldnt get that info either so thats why I ground the teeth off the intake cam and used only the exhaust for timing.

We need someone to confirm WHICH cam the code uses (intake or exhaust) since they have different number of teeth and if the code allows for BOTH cam inputs for VTC use.

I believe if the code uses the intake cam pattern then youll have issues if using the exhaust cam sesnor for timing. Hope that makes sense.

If your not working in COP add 180 degrees to your cam offset AND check that you have the correct spark output to the correct coil. ie. spark A = 1, spark B = 3, spark C = 4, spark D = 2. Setting firing order in the software is for injector timing only and will not effect the spark outputs.

[cukali]

From what I understand, the code your using is from another user. They may have written it using the intake cam sensor patter and not the exhaust.

I modified my sensors to work since I knew ahead of time there wasnt a code specifically for the Honda K series. Since you already have the engine together, cutting teeth is not an option for you. You need to find out wich cam sensor the code your using was written for. The intak CAS wheel has 5 teeth, the exhaust has 4 teeth. The intake has 4 teeth 90 degrees apart (just like the exhaust) but has one extra small tooth at TDC.

see here...

http://www.google.com/imgres?start=136& ... EK0DMDY4ZA

Did the other user have VTC working? Did they use intake or exhaust CS for timing?

[cukali]

From what I understand, the code your using is from another user. They may have written it using the intake cam sensor patter and not the exhaust.

I modified my sensors to work since I knew ahead of time there wasnt a code specifically for the Honda K series. Since you already have the engine together, cutting teeth is not an option for you. You need to find out wich cam sensor the code your using was written for. The intak CAS wheel has 5 teeth, the exhaust has 4 teeth. The intake has 4 teeth 90 degrees apart (just like the exhaust) but has one extra small tooth at TDC.

see here...

http://www.google.com/imgres?start=136& ... EK0DMDY4ZA

Did the other user have VTC working? Did they use intake or exhaust CS for timing?

I seen your video of your VTC going from 30 to 150 degrees and back....oddly enough, that the crank degrees that is between the extra tooth on the cam sensor and the next tooth. Looks to me like the code wasnt written to decode the intake sonsor..its counting 4 teeth but reading 5. I would suggest cutting all but one tooth of the intake CAS wheel BUT only after you find out which cam the codes written from.

[Barton]

I did a lot of tests, the engine does not start using the intake cam sensor, if I check the timing (using the exhast cam sensor) the timing light shows the spark timing of the ts matches the marks at the crank pulley perfectly in both modes (wasted cop and full cop) just when cranking if I add 180 degrees the strobe light shows the same but in cop losses the marks (It means that 14 is the correct offset). But it will only start in wasted cop.

I checked the timing with the strobe light even at 7k rpm (wasted cop and locked timing) and is perfect as the ts says. If you see the vtc does not go crazy when detects 180degrees. I wouldn't like to chop teeth because the engine is already running just need to check that behavior

[cukali]

Thing is, if you have the timing off by 180 degrees on the cam OR you have the coil wires on the wrong coils, you will still get the timing light to read correctly on the crank. Remember, the crank has to go around twice for each cylinder so if you are NOT running on COP but in wasted, you will see the marks correctly on the crank pulley BUT it will be firing on the wrong cylce.


Check the firing order again, OR change the cam timing 180 (360 crank)

There is no other solution to running good in wasted but not in COP.

IMO you probably have the cam degrees correct and the problem is in the coil wiring but adding 360 to your cam timing is easier than rechecking all the wires.

[juansh2385]

If your car starts in wastes spark but not in cop you need to add 360 to you trigger angle as mention before if it starts ( probably will) then you inform james that the decoder need a 360 phase change (make sure you have spark outputs A in cylinder 1, Spark b to cylinder 3, SPARK C to cylinder 4, and spark D to cylinder 2 same with the injector order for sequential fuel)

Juan

[Barton]

Thing is, if you have the timing off by 180 degrees on the cam OR you have the coil wires on the wrong coils, you will still get the timing light to read correctly on the crank. Remember, the crank has to go around twice for each cylinder so if you are NOT running on COP but in wasted, you will see the marks correctly on the crank pulley BUT it will be firing on the wrong cylce.


Check the firing order again, OR change the cam timing 180 (360 crank)

There is no other solution to running good in wasted but not in COP.

IMO you probably have the cam degrees correct and the problem is in the coil wiring but adding 360 to your cam timing is easier than rechecking all the wires.

If your car starts in wastes spark but not in cop you need to add 360 to you trigger angle as mention before if it starts ( probably will) then you inform james that the decoder need a 360 phase change (make sure you have spark outputs A in cylinder 1, Spark b to cylinder 3, SPARK C to cylinder 4, and spark D to cylinder 2 same with the injector order for sequential fuel)

Juan

Belive me I've checked all of that that at least 20 times!, I even recorded a video to whatch it in slow motion to see if the sequence was fine.

[Peter Florance]

If your car starts in wastes spark but not in cop you need to add 360 to you trigger angle as mention before if it starts ( probably will) then you inform james that the decoder need a 360 phase change (make sure you have spark outputs A in cylinder 1, Spark b to cylinder 3, SPARK C to cylinder 4, and spark D to cylinder 2 same with the injector order for sequential fuel)

Juan

^ this seems important to me. Especially testing with 360 added.

[Barton]

If your car starts in wastes spark but not in cop you need to add 360 to you trigger angle as mention before if it starts ( probably will) then you inform james that the decoder need a 360 phase change (make sure you have spark outputs A in cylinder 1, Spark b to cylinder 3, SPARK C to cylinder 4, and spark D to cylinder 2 same with the injector order for sequential fuel)

Juan

^ this seems important to me. Especially testing with 360 added.

here you can see the spark sequence (this means the wiring is ok, the order is from the botton to the top 1 to 4.): http://youtu.be/AXJf_MXHaKg

if the wiring is ok, then it should start in 14 degrees (this value was obtained with the timing lamp in wasted cop mode) or 374 degrees, if the wrong offset is selected I'll get backfires, but in my case for both values (14 and 374) I get backfires. Already checked a lot of times. a month ago I talked to james by email but seems he's not around these days.

[cukali]

If your car starts in wastes spark but not in cop you need to add 360 to you trigger angle as mention before if it starts ( probably will) then you inform james that the decoder need a 360 phase change (make sure you have spark outputs A in cylinder 1, Spark b to cylinder 3, SPARK C to cylinder 4, and spark D to cylinder 2 same with the injector order for sequential fuel)

Juan

Well I looked at your calibration for the first time just now and there are some things you may try to change.

Dwell for the Honda smart coils is 2.5ms. Running at 1.5 may not yield enough energy to fire them. Possibly this could cause very weak to no spark while running.

Make your cranking dwell 3.0 and running dwell 2.5 (minimum) Dont go above 3.0 while running.
Spark duration is 0.1 for these coils also.
There is a spark latency, I forgot what I measured it to be but I believe it was around 90us. This wont cause your problems though.
Use "no prediction" for spark advance.
Your injector timing is off

For the coil wiring, make sure the middle wire for each coil goes to a common ground on the cylinder head.
Try seperating the coil wires from each other and away from the CAM sensors....see if that helps.
Try using "falling edge" and add about 30 degrees to your cam offset.
The TSX runs factory MAP sensor.. use Speed Density.

Make the above changes in the order I listed and only one at a time....try COP after each change.

BTW, give Marudo a kiss for me. (the bastard) My brother is a Docter in Venezuela and my wife is from there.....what a mess it is right now.