OK, getting ready for the bi-annual smog check. How do you tell if the VSV is working correctly? Haynes manual I have doesn't go into much detail...

Any help appreciated.

They vary a bit among the different years. Assuming it is a 74-78 FJ40, if you listen carefully, you should hear the VSV click when you turn on the key. You should also notice your throttle positioner working as it will hold the RPM above 1200 until the speed drops below 10-15 MPH. You should also see vacuum on the EGR line with the engine warm when you rev up the motor to 2500. It will also retart the distributor under high speed cruising, but this is harder to check.

Thanks Pinhead. I think this helps narrow things down a bit. Yeah, the Throttle positioner doesn't appear to be working. The vacuum diaphragm is working as evidenced by sucking on the line. Looks like a wiring issue.... hmmmmm.

Depending on the year, the VSV is basically just a bunch of solenoids. What you need to do it put 12V onto the one of the connectors (my 78 was pin 6) and then ground each of the other pins one at a time to hear the solenoids click (mine has 4 solenoids). Make sure your EGR works, they will check it. When your rig gets up to temp and you rev the throttle, the VSV should open, pulling vac from the BVSV and create a bubbling noise in the carb. This is the EGR opening and letting exhaust gasses back into the carb.

I just went through all of this and finally got my rig smogged last weekend. Let me know if you have any questions. Oh yeah, get yourself a Mighty Vac if you want to check the functionality of the system and/or the individual components.

Thanks Eric. I'm getting some great info here. For a Mighty Vac, I'm planning to use my lungs!

Clark

Lungs work too! LOL

I have an emissions manual for my 78....so if you need some test procedures, I can help. What year is your rig?

If the TP isn't working, it is stuck on high idle unless someone has adjusted the high idle screw on the TP to compensate. TP line should have vacuum when stopped at idle. Check for vacuum on the EGR line too when you rev it up when the engine is hot. Like Eric says, the VSV is a bunch of solenoid valves that generally don't go wrong and are easy to check. The most common problem is with the pea brain computer (especially 74-77). The computer is inside the cab on the firewall next to the clutch. It has a large electrical connector on it. The vibration of this connector cracks the traces on the printed circuit board. To check for this, turn the key on and wiggle the connector. If you hear the solenoid vavle clicking, then you may have a bad connection. Take the PC board out and resolder all the connections.

Yeah, what Pin Head said.....take your computer out and resolder all of the connections. My VSV worked just fine, but there were a few cracked solder joints on the computer that prevented the VSV from switching. After I soldered up all of the connections, the VSV worked just like it was supposed to.....except for that carb temp sensor that activates the EGR switch.

Damn! This is great guys. This is for a '76 FJ-55 California Spec vehicle. Any chance I can get test procedures from an Emmissions manual? I can probably work with wht ya'll have provided, but the more info the better!

Clark

When your rig gets up to temp and you rev the throttle, the VSV should open, pulling vac from the BVSV and create a bubbling noise in the carb.
Great info so far. Check your Haynes or factory manual for info about your particular year. On my '75, the computer is not only temperature dependent but also speed dependent. The speed signal to the computer comes from the sensor on the speedometer cable cable at the firewall. Just reving the engine will not activate the VSV. It has to be in gear with the speedometer turning.

The bubbling noise that Eric mentioned is very important too. Most of the technicians at the smog shops that I've been to are not familiar with the older EGR system on the cruisers. Opening the EGR will not stall the engine like in most cars nowadays. I've had techs try to fail me in the past because the engine didn't stall, until I showed them a copy of the factory emissions manual which shows that you need to listen for the bubbling noise.

Originally posted by Screwzer
Damn! This is great guys. This is for a '76 FJ-55 California Spec vehicle. Any chance I can get test procedures from an Emmissions manual? I can probably work with wht ya'll have provided, but the more info the better!

Clark

Save yourself lots of potential headaches and order an emissions manual from SOR. It will have the diagrams, schematics, test procedures, and trouble shooting sections. Money well spent if you plan on keeping the 2F.

http://www.sor.com/sor/result3.tam?xax=32263&uu=1489830
It looks like there are 2 manuals for 76....
#223-06-76 $12.99
#223-06-76-CA $19.99

I would call them and ask which one is the correct one (they will probably say both...LOL). The CA one is a suppliment manual so you may need both.

I hope this helps some.

Originally posted by Shipwreck

Just reving the engine will not activate the VSV. It has to be in gear with the speedometer turning.



That is what I used to think about my '76 too until I watched my smog technician test it in N w/o the dyno. It has a vacuum even when the speedo is not turning. Maybe the '75 is different?

I have a copy of the Toyota '76 CA emissions manual if you need copies of the relevant pages, just give me a shout.

'76 California Emission Manual pages would be great! What works for you? Fax or e-mail? PM me for specifics.

Tanks

Clark