mxt_77

Assuming you floored it in that last little bit, your car is definitely not healthy. Even pre-VTEC it was slow to accelerate.

If you're bouncing at 6K, that sounds like the cold rev limiter (or maybe the rev-in-neutral limiter?). Search on the cold limiter, I forget what all the parameters are for engaging it, but there's a post around here somewhere. I know that one is water temp, but maybe oil pressure is also involved.

NVMY4N

I didn't floor it.
I was just being cautious, I didn't want it to bounce off 6k very many times.

But it still could be unhealthy. I dunno

mxt_77

But when you say "bounce"... do you mean like a rev-limiter? I didn't realize that was the problem you were describing. I just thought you meant that it accelerated slowly.

If it hits like a rev-limiter, then it's not the MAP sensor issue.

NVMY4N

yeah it's like it hit the rev limiter.....Jeff described it as (not a direct quote) not all the cylinders hitting vtec. (I think that's how he put it)

BUT

Now it's not even trying to engage vtec.

SenderGreen

Replace map sensor and Zip-tie it per the TSB (if it's not already). If for no other reason than to rule it out. You may even be able to get a dealer to do it for free, especially since you are having a problem that could be described as: Intermittent hesitation during hard acceleration.

yms2k

I bet your cat is clog, remove it and take it for a test run without a cat. I know its loud but it will work. I might sound stupid know, but you'll thank me later. If your cat is clog, a temp. fix would be to use a long metal bar and break out all that crap inside the cat, low budget testpipe. Peace.

NVMY4N

Thanks for all the suggestions.


tomorrow if I have time Im going to change the oil and Ill look at the cat. (its a Comptech Cat) if that doesn't work.....Ill have to seek professional help. Unfortunately that's a few states away.

RED MX5

The nature of the problem seems to have changed while you were making the video. On the first two attempts it sounds exactly like the rev limiter, only it's cutting in at about 6,200 RPM. On the last pull, it sounds as if the car just runs out of steam at 6k.

It is entirely possible that this has nothing to do with VTEC engagement; The fact that it happens at the same engine speed *may* just be a coincidence. For that reason, I'd check the easy stuff (like the MAP ) first. However, the fact that the problem is happening right at VTEC engagement may well point to a VTEC problem, so that's what I'd be looking at after the "MAP whack." If you know that the selenoid is working properly, and that it is getting the proper signal from the ECU, and also that the screen in the VTEC valve is not plugged, then you need to *measure* the actual oil pressure as described in the shop manual. If there isn't sufficient oil pressure VTEC will not engage, so that *might* be what's causing this.

OTOH, in the video it doesn't really sound like a failure of VTEC to engage, and that's what's confusing me most at this point. If VTEC does not engage the low profile cams should allow the engine to rev well past 6k, though power will fall off rather than pick up. Different fuel maps and timing maps come into play during VTEC, but I don't think the car will fall flat on its face at 6K the way yours is doing just because it's still running on the milder cam profiles. I have not actually seen this happen and am only guessing, but it looks more like your car is hitting some kind of hard limit, and failure of VTEC to engage should (I think) look more like a very soft limiter or just running out of power gradually.

LOL, I guess what I'm saying is that I haven't got a clue. My biggest concern would be insuring that the car was not losing oil pressure for some reason. Probably not the case, but I'd want to be sure, because if that *is* the cause, driving the car is a really bad idea.

ROLLINS

RedMX5, I'm not sure that Brad pointed out that he swapped the vtec solenoid the other night. While I had him on the phone he checked to make sure the solenoid valve was moving freely, and it was.

RED MX5

I wouldn't be surprised if he mentioned it and I overlooked it. Hard to keep up with all this chatter going on.

If we know that the solenoid valve is good and getting a signal, and that the oil screen isn't plugged, then there is only one thing I know of that would keep VTEC from engaging, and that's insufficient oil pressure. However, after watching the video I'm not sure this is a VTEC problem, so who knows? Anyway, if the valve is opening and the oil passages aren't blocked, and there is sufficient oil pressure, then the oil pressure WILL pin the rockers and engage the more aggressive cam lobes.

I'm wondering how the car behaves when the ECU goes into "limp mode" and also trying to figure out what could be going on (other than a VTEC engagement problem) without throwing a CEL.

We need to bet Billman or one of the other Honda Techs involved. One of them may recognize the symptoms from the video.

Billman!!!