Need help diagnosing - Honda Prelude Forum

Gmachine · 08-19-2006, 06:54 PM

I've made an appointment w/ the Honda dealership to look over my Lude on Monday, but decided to tear into it today and see if I can't find something myself.
It spuratically gives me a CEL and the Vtec doesn't seem to be working.

I have a Helms and going throught the steps to check the Vtec Solenoid I found it to be faulty so got a new one.

Today I went through hooking air up to the Vtec system around 36 psi with the hole blocked off & cylinder at TDC and couldn't get the mid rocker to engage. I assume this to be a problem.

I did adjust the valves about two months ago. Only three were out and only by a few .001-.003 each.

I tried doing a leak down, but without the fancy snap-on gauge. I don't know if I did this right as I am only able to reach 170 psi here at home, but I could never get it to leak harsh enough to listen or even see the gauge move much. It would drop after a few minutes, but nothing quick for sure.

I've replaced:
Front 02 (which keeps fouling out and throwing a CEL) Seems ok after cleaning and reinstall. Lasts about 700 miles before it throws CEL again
Cleaned a very dirty EGR (that threw some kind of future problem code)
Did a compression test 190-210 all 4

I'm going to hook up an oil pressure gauge and see what I've got there. I just don't understand what else I need to look at. I still don't feel that Vtec is working properly and don't know what could cause my driveability issues. I'm commuting 100 miles a day and don't want a serious problem to arise in the future.

Gmachine · 08-20-2006, 11:11 AM

I just checked my oil pressure and it seems at idle its at 12 lb. and at 3000 rpm it around 65-70 so that looks good.

So far it looks as though my rocker arm assemblies are bad or need cleaned and freed up. I checked Majestic and they want $98 per assembly!! being I couldn't get any of them to work it's going to cost me $800 or so? I did notice that air was escaping between the rocker arms as I was testing it yesterday. Would the oil have drained and caused me to loose what has to be in the rocker arm assembly? I also couldn't seem to check the oil pressure from the passenger side front bolt that the Helms told me to hook up to?? It did allow air to enter though. Maybe a check valve in there? I'm using just a basic interior oil pressure gauge.

Any suggestions?

Gmachine · 08-20-2006, 02:46 PM

Well I did the redneck thing and hooked up the oil pressure gauge to the bolt in the front of the head, pass/ side and taped the gauge to the windshield. Drove down the road and nothing! I thought maybe I had to run the car above 5200 RPM w/ load, but that didn't get me anywhere either.

Gmachine · 08-20-2006, 07:49 PM

Is everyone as clueless as I? 40 views and no reply? Or do I have to go through some sort of innitiation?

I've done searches and didn't come across any info. similar to this. I'm not asking for random guesses either.

I'm not upset, but I come from the Turbo Buick world that was close knit and very specialized when it came to that model. We either figured it out ourselves or bust because GM wasn't willing to lend much support. We only had to worry about going straigh quickly

We didn't even have to shift as all are autos!

98PreludeSHDrvr · 08-20-2006, 08:35 PM

What is the check engine it gives you? Is it the O2 sensor? If you replaced the primary O2 sensor only to have it fail a few hundred miles later it means that something else is the problem. I'd start with checking ignition cap, rotor, wires, ICM and fuel pressure first. Also, I believe that if you are throwing a Check engine light Vtec will not engage.

Gmachine · 08-22-2006, 01:36 PM

Yes, it give a CEL for a rich condition I foget the number, 1259 or so. My main concern is why I'm not getting any oil pressure from the point that Helm says I should. I even hot wired the Vtec Solenoid while above idle and couldn't seem to get it to work that way either.

Any ideas?

I've ordered a fuel pressure gague I'm going to put on the end of the rail to be able keep an eye on that.

I'm stumped!

98auto · 08-23-2006, 03:16 AM

have you reset the ECU?

BBYlude · 08-23-2006, 07:14 AM

If it helps, my car always has a CEL (flashing or solid) lit up and I can run Vtec as often as I want all the way up to redline. With that in mind, the computer shouldn't be disallowing vtec from engaging unless it is objective to certain CELs, which I wouldn't know. I would think that if your Vtec solenoid is good, then it is either oil pressure or your oil passageways. It looks like oil pressure is good, so might there be a blockage? Is that screen on the Vtec solenoid clear?

Gmachine · 08-23-2006, 08:14 PM

Yes, the screen is not only clear, but new as I ordered a new gasket and screen. The old one wasn't clogged or anyting, but I did replace it.

I just don't know where to start to look for a blocked passageway? Any time I've had the vavle cover off there was plenty of oil sitting around, but there's obviously a block somewhere as I'm not getting oil pressure where I should and Vtec isn't working.