Hello,

I recently replaced the head gasket on my 1995 2200 5SFE Camry LE and I was able to place everything back the way it was, except for the vacuum switching valve. This is the only piece that I did not mark the lines to and so I am not sure if I have the lines in the right spot, or if I put it in backwards. It also seems to be in an area of the engine where there is alot of tension on the lines to it, so I am not even sure if it is in the right spot.

The reason I suspect the vsv is that ever since I put the engine back together, I seem to be getting some unexplained knocking (code 52) and I have to retard the timing back to about 2 ATDC to get it to stop, as opposed to the standard 9 BTDC. Since my homeowners association has an affinity for towing my car when I try to fix it, and it is impossible to get to the vsv while the car is hot, I was hoping that someone out there would be able to shed a little light on the situation before I risk getting my car towed.

Anyways, the car never knocked before I changed the head gasket and I was wondering if this vsv problem could be causing it. Also, if it is not the vsv, what else could be causing the knocking? I used an octane booster in the fuel last time I filled up, so I do not think it is bad gas.

I know this is a long post, but I basically have 3 questions:
1. What is the proper location and way to plumb the VSV?
2. Could a backwards VSV cause the engine to knock?
3. What beside gas could cause the engine to knock after replacing the head gasket?

Any help I could get would be most appreciated.

Thanks,
The Dude

 

Code 52 is the knock sensor circuit. The computer tests the knock sensor for an open or short circuit. Is the wire to the sensor connected?

The sensor should have an ohm resistance greater the 1M ohm.

There should be 2 hoses going to the VSV. The valve has a vent on one side that looks like a little ****, a pipe on the opposite side of the valve and another pipe in the middle of the valve.

The hose from the vacuum modulator goes to the pipe on the opposite side of the ****. The hose from the EGR valve goes to the pipe between the **** and the pipe at the end.

The EGR looks like the photo in the link below:

http://www.rockauto.com/catalog/moreinfo.php?pk=444177

 

Well, I'm not sure if anyone is going to read this, but I figure that I would give a follow up anyway.

First of all, I figured out what was causing the knock sensor code. I talked to a mechanic who works mainly on Toyota and he said that the 5sfe knock sensor connection likes to corrode rather bad over time and that if it just barely gets brushed, it can make the computer think there is a knock. He suggested to replace the sensor and the wire leading to it, but I found that a generous application of WD40 along with scrubbing with a Q-tip is enough to get rid of the corrosion and fix the problem.

Second, I DID have the VSV installed backwards, and it did cause a few problems. First, it somehow caused the car to idle low/rough. Second, if the car was revved up while in park, then let off the throttle completely, it would die. Finally, it made the engine lose much of it's power, and after correctly installing it, the power went back up, as well as getting more miles to the gallon.

I have not had any of these problems come up again, and I have since driven from Texas through Oklahoma, Colorado, Wyoming, Utah, Idaho, Oregon, Washington, Oregon, California, Nevada, Arizona, Colorado, Utah, Idaho, Oregon, and back to Washington. After solving these problems, I went from a 12.6 second 0-60 to a 9.8, and from 27 mpg to 32.