P1259 and sluggish top end
 

When I first bought the S about 3k miles ago (came with a vafc2 installed) it threw a cel code P1259 which is a vtec malfunction. Since then as long as I dont hold the car in vtec very long this has not been an issue and vtec still comes on strong. The other day I was jut having fun and noticed that the top of second felt slow. Yesterday rolling from 20 in first gear I went full throttle all the way to 9k and vtec did crack on. Once the car gets to about 7k the car feels choked. The acceleration is very slow, I can pretty much watch the speedo go 36...37...38. No CEL came on though. The oil is a hair below the Full line and I have cleaned the map sensor.
What could cause sluggish high rpm acceleration? Is it possible that the original VTEC CEL I got has just gotten worse?
For the P1259 code the solution Im finding on this forum is to replace the VTEC oil pressure switch, could replacing that fix both problems?

Thanks for any help guys!

anyone have any ideas?

As long as you are feeling VTEC engage then it is fine barring any further CEL's for that code.

As far as sluggish top end I'd suspect the spark plugs first, do you know how old the plugs are ?. Secondly, what are your programmed settings for the VAFC ? - fuel and vtec point ?. Running rich can hurt top end performance, more so for ap1's. Let us know about your plugs and any VAFC settings you have.

I am not aware of how old the plugs are. I will pop them out when I get home and see if they show any signs of fouling.
I have vtec set at 6k. I will check on fuel when I get home from work.
The vafc settings haven't been touched by me since I have owned the car besides messing around with the vtec point a little bit and it has ran perfectly fine up until now.

Yeah let us know what you find.

With the plugs it would be good to know the colour of the plugs and how large the gap is, as the plug gap grows over time. When you go to remove the plugs pay attention to how easy they loosen on removal, loose sparkplugs can be an issue on ap1's. Remember to torque the plugs to 18 -20 ft lbs when you re-install them.

A quick test with the VAFC would be to return the car to stock settings and see if it runs better, worse , or the same. You can always put the settings back after the test. A 6K rpm point is the same as stock so you aren't getting any benefit there. With fuel settings you can get a bit more power by leaning out the fuel, if the previous owner was richening up the fuel settings that could cause you to lose power on an ap1.

Not super familiar with the VAFC besides changing the vtec point. How do I revert to stock settings? can the vafc unit be turned off or does it need to be unplugged?
I put the vtec point back to stock to stay out of vtec a little more as I mostly just cruise around. When looking for the most power/speed what is the recommended vtec point?

^ this could be part of your problem. Did you get a manual for the vafc when you got the car ?. If not try to download one.

For the fuel settings go through and see what they are set at for each rpm point. A positive number is richening (adding) fuel by that percentage, zero is leaving it at the stock fuel setting, and a negative number is leaning (decreasing) the fuel level by that percentage. Make note of the current settings, and just change them all to zero to leave the stock fuel settings.

The best way to set the vtec point is on a dyno to pick the rpm point that maximizes power, if you don't have access to a dyno I'd leave it at the factory setting. You could decrease the vtec point in the range of 5,000 to 5,500 ,but without a dyno you really won't know how it is working.

Let us know what you find out on the fuel settings and other info.

Here is my Wide Hvt Fuel settings
5500- 0
6000- -3
6500- -2
7000 -3
7500 -5
8000- -8
8500- -10
9000 -15

hmmm, the mid-range doesn't look to bad, top end is leaned out a bit though. Try doing some runs with the settings put back to stock and see if you can notice any difference. Thanks for posting the info.

The short answer is YES

1259 code will disable vtec, but you should feel it jerk a bit and not come on. A vafc can exacerbate this OEM problem, or it could be entirely the VAFC malfunction or user error. Best advice for trouble shooting this is to disconnect the vafc all together and drive the car, if the 1259 code comes up again, then you know its an OEM issues and you need to deal with this.

Here is some crappy cell phone video of full throttle pulls with car on stock settings

http://s1108.beta.photobucket.com/us...b4948.mp4.html

http://s1108.beta.photobucket.com/us...95074.mp4.html

Getting rid of the VAFC would be my first step.

How do I go about getting rid of it?
Isnt it soldered into the wiring harness?

Cyl one spark plug is very white and looks worn out to me. It was within spec for gap though. Cyl 3 and 4 have a very light brown to it.
http://i1108.photobucket.com/albums/...psae00070e.jpg

On cyl 3 coil pack there appears to be a light coat of rust powder?
http://i1108.photobucket.com/albums/...ps5d4090f9.jpg

Should I replace the plugs or torque the old ones down?

The plug colour looks normal. The dust on the coil is just from the boot as it ages, I don't think it's anything to worry about.

What were the gap measurements ?. If they are the original plugs I'd consider replacing them, if you think they have been replaced wihtin the last couple of years then just re-torque them to spec - 18-20 ft lbs.

Looking at your videos the top end rpm climb didn't seem all that bad, the lower mid-range seemed a lot slower to me though. :ponder: , hard to say though.

they were about .039 which is the edge of within spec. I will probably be replacing them within the next few days.
Here is a video I took with my gopro. Holding full throttle the motor gets stuck at 8.5k
http://s1108.beta.photobucket.com/us...28116.mp4.html
What could cause that?

if your plug gaps are .039" then they are relatively new, you don't need to replace them. They come with a gap of .039" out of the box, the service limit for replacement is .051".

The 8500 rpm issue is odd, it's almost like you have an 8500 rpm redline. It seems to accelerate fine up to that point. Does it feel like the engine is droping out of vtec at upper rpms ?, maybe you have oil pressure issues or the vafc connections are causing issues. In that video were you still running the leaner fuel settings on the top end ?. Maybe you are getting detonation on the top end and the engine is cutting out.

Your vafc low to high vtec setting is 6000 rpms, what is the high to low vtec setting ?.

In that video I have the vafc set at stock settings.
The high to low is set at 5300
The feeling is hard to describe. Once it felt like it dropped out of vtec. If I was dropping out of vtec would that cause the early redline?

How do I test for oil pressure?

I took the VTEC solenoid off to check the screen and it is very clean. The oil pressure switch I noticed had some oil in it. Could the switch be leaking? I did clean the oil off.

It's really hard to diagnose over the internet but if it drops out of vtec the low speed cams won't make any power at 8500 rpms and you could be running into a wall power-wise. I don't know if the ECU has some safeguard in case vtec disengages at higher rpms either. With detonation the engine reduces power to keep it safe, but if you weren't leaning out the fuel settings in that video you were likely safe from detonation issues.

If you are finding oil in the vtec switch that will short the switch and cause vtec to disengage in cerain conditions, that could be the issue.

Yea I know it is. I appreciate your continued effort to help me out.

Also it is only under load. In neutral I can rev it right to the 9k limiter.

Are those switches known for letting oil in? should I replace it or would that not resolve finding oil?

It started happening on its own without me changing or adding anything So I am guessing it must be something that just built up.

Where do I hook up a gauge if I want to test oil pressure?

I have read some posts recently about guys finding oil in the vtec switch. I think the fix is to replace the switch or find a good used vtec solenoid unit.

You have to remove the oem oil pressure switch and put in a proper sized oil pressure gauge to measure the oil pressure. But since you have mentioned finding oil in the vtec solenoid switch I am starting to think that could be the source of your issue, definitely the first repair to pursue. The low speed cam might not have enough power to accelerate the vehicle in motion but can rev the engine to 9000 rpms stationary ?, just a guess. Someone like Billman250 is better able to tell us if this is a possibility and how oil in the vtec switch might be related to your issues.

Replacing the switch should stop the leak? dont wanna ruin another one of these.
Hopefully Billman can chime in on that.

I will be ordering one here soon. hopefully that does the trick.

http://www.hondapartsnow.com/genuine...0-PCX-A02.html

^^thats the correct part correct? Cheapest I found with shipping. Let me know if you know of a better place.

Part number 16 is the switch, and part 23 is the o-ring which go together.

I don't really know if that will stop the leak issue, I don't want to promise you that as I've never seen it before. There was a post on here a couple weeks ago where some member had changed his switch a few times and it always leaked. I don't know what the outcome was , maybe try a search for that post, and see if anyone can offer more info on this. I'd hate for you to spend money on parts and not find the problem.

I guess I will order a new one. see what happens. Should I put any sealant on the threads when I install the new switch?

Make sure to get the o-ring that goes with it for sealing purposes. I am not sure how oil is getting into the switch, if adding a non-hardening sealant on the threads like Hondabond (Permatex Ultragrey) would help. It might be worth a try if you keep it to a light skim coat.

Try to find the guy that had oil leak issues in his vtec switch within the last couple of weeks on this forum and see if he resolved his issue. I was trying to help him out too by replying to his thread, but I don't know if he got it resolved. According to him he was getting oil leakage in numerous switches that he installed, so I don't know what causes that. If I find the link to his thread I will post it up in this thread.

Here is the link to the other thread, maybe contact the original poster and see if he resolved his issue

https://www.s2ki.com/s2000/topic/100...aking-no-vtec/

sweet pmed him. Ill update here when I install the switch.
Fingers crossed for fast shipping :)

Good luck, I just couldn't understand how he was getting multiple switches with oil in them, I hope it works out for you.

So I ended up canceling my order for the switch which was 60 bucks shipped and bought a used solenoid and switch from a guy on the forum for 30 bucks shipped.
I am very happy to report that this did indeed fix the problem. I am one happy camper sitting here eating the box of milk dudes that I got after vtecing all the way to the store and back :D

I am assuming it was the switch that was bad but can not be sure as I just switched out both the solenoid and switch.

One more question, I am going to revert my VAFC back to the settings it had before. Should I be concerned with the -15 at the top end being to lean?