Re: 79 C10 Can't find EGR Thermal Vacuum Switch @

Posted by Bob on November 27, 2005 at 10:08:34 from (64.21.249.40):

In Reply to: 79 C10 Can't find EGR Thermal Vacuum Switch @ Stor posted by Curt on November 27, 2005 at 08:41:53:

First of all, is it definitely the TVS (temperature-vacuum switch) for EGR, and NOT involved in EFE (early fuel evaporatation)... the vaccum-controlled valve on the exhaust manifold?

Is the TVS you're looking for located in the thermostat housing above the thermostat, or screwed into the intake manifold itself?

EFE=Good for the engine... heats the intake manifold up upon cold starts for better vaporization of the gasoline=cleaner burning, less oil contamination.

EGR=BAD for the engine, GOOD for passing emissions testing... makes the engine eat it's own exhaust.

What will happen to your engine without EGR? Well, it will run cooler, cleaner, and happier without EGR.

The only exception is if it is carboned up a bit, and has higher than normal compression. In such a case, the lack of EGR may tend to cause a bit of ping, or spark knock under heavy acceleration.

The purpose of EGR is to reduce NOX emissions. If you are not subject to emissions testing, you will be just fine without the EGR working.

If you NEED to have EGR, or are simply determined to ifx it, what engine do you have?

If your engine is the common 350, and you need the TVS on the thermotat housing, here's some links:

ACDELCO Part # 21264, GM part # 52499519 (W/O California emissions)

http://www.rockauto.com/ref/ACDelco/Detail.html?212-64.jpg

ACDELCO Part # 21245, GM part # 52499498 (California emissions)

http://www.rockauto.com/ref/ACDelco/Detail.html?212-45.jpg

Does this look like the TVS you need, or are your vacuum ports on a more square pattern?

If this looks like what you need, you can order it on-line at Rockauto.com, or use the part numbers at a local GM or AC Delco dealer.

If you need the other style, or for a different engine, post back, and I'll try to dig up some other numbers.

Follow Ups:

• Re: Re: 79 C10 Can't find EGR Thermal Vacuum Switc Curt 05:56:09 11/28/05 (1)
  • Re: Re: Re: 79 C10 Can't find EGR Thermal Vacuum S Bob 08:37:41 11/28/05 (0)

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