In the middle of my engine swap, and today i was assembling the intake. Yeti had to abruptly stop becuase i then relaized, whoops, i am removing egr, not putting it back on.

So my question is the stock EGR valve assembly, does it come apart, or am i going to have to saw the actual valve part off? I am going to fill all the holes with JB Weld and just use it for a temporary solution until i get an egr blockoff plate.

Does anyone have any pics of the way they removed EGR?

Oh and one more question, on the front of the intake baseplate there is a colant sensor, and another sensor/switch. which one is this? It has the connector like a fuel injector connector. And the fitting is huge, i used a 1" wrench to remove it, and i still broke the ceramic ending off. So what does it do?

 

i made an egr blockoff plate, dont worry.

went to home depot and got a seemingly thick piece of aluminum. cut it with my dremel to size, tjhey wern't the curvious turns, but they worked. And Drilling my new holes. works great.

 

what will happen on a MAF car if you remove the EGR valve? will it run bad? i might be switching to HSR which doesn't have EGR

 

If you yank the EGR, you'll start throwing codes. The EGR valve has a sensor that detects gas flow. If the computer is commanding the valve open, and it doesn't detect flow, you get a code.

 

What sensor is this that detects gas flow? I've never heard, nor seen it.

Ran my HSR when I first got it without EGR, and had EGR enabled in the chip still... no codes, no problems...

 

There's no gas flow detection, only temperature via a bi-metal temperature switch screwed into the base of the EGR valve.

 

That one wire porcelain thing? That wire broke off when I still had TPI and never caused a problem. Weird. My 4.3L Jimmy doesn't even have a wire for it. Maybe it's a TPi vs TBI thing.

 

EGR prevents The formation of Oxides of Nitrogen (NOX)
by taming the combustion event and limiting peak combustion tempertures during cylinder combustion.
Becuase exhaust gas cannot burn twice the fuel burn rate is slowed by EGR flow at part throttle cruise.
Because the burn rate is slowed by egr the computer or distributor is set up to add additional ignition advance at part throttle to correct the burn timing.

If the EGR is disabled the motor will likely ping at part throttle and or while rolling into the throttle to pass a car.
The cure is to reduce ignition timing at part throttle to correc t the now over advanced ignition timing.

When egr is functoning right it actually results in a slight gain in fuel mileage overall along with reducing NOX emissions.
Egr does not affect idle quality or WOT performance as it only works at part throttle cruise mode while driving.

EGR is your friend.

 

hmmn so that makes the HSR a crappy intake for our cars (if i want to be streetable and pass emissions while not spending another $500 reprogramming the chip). okay i guess teh HSR is out. what pther intakes have egr provision besides superam.

 

addendum: on some, but not all. Still haven't seen the why or a concise list of what came with what, but it does seem that most '89 TPIs had the switch... which as mentioned detect temp change not gas flow.

The EGR doesn't itself prevent the NOx formation, it keeps the potential peak combustion temps low enough to prevent those oxides from forming, though you can tune the engine to acheive the same result through various means. Nor will you get a ping at part throttle depending on tune, cam, etc.. Oddly worded I gess, or I read it oddly. :shrug: Though, yes, the EGR is your friend and I need some sleep.

 

True some engines with long cam timing ( overlap) tend to have a sort of built in EGR ( exhaust backflow at low rpms) This is what causes the "rough racy idle". But too much combustion taming results in incomplete combustion raising HC and CO content in the exhaust. As well as reducing fuel mileage.

Its a fine line. Not cut and dry.

Holley should have made the SR manifold with a spot to mount the EGR valve at least so it would pass a visual inspection during emissions testing. Then you could have a choice wether to plug the EGR passages or.... to suite your needs.

 

agreed,

 

So make an EGR valve flush, mock some bolt heads, glue it to the manifold, hook a vacuum line. Bam visual inspection.

the HSR is a GREAT manifold for ANY car, as long as the engine is matched. Put it on a stock 305 like a guy I know did, and see no gains + a tuning nightmare. Put it on a built 350 and you've got 12 second runs all over it.