Should the vacuum line going to the EGR hold a vacuum? With the engine cold and not running if I pull the hose coming from the carb to the EGR valve and attempt to pull a vacuum the EGR valve leaks at the holes under underneath. If I blow smoke back into the hose the smoke comes from the bottom of the EGR also. The vacuum solenoid does not appear to be leaking.

Thanks,
Andy

 

Yes, your EGR is bad. If it doesn't hold vacuum it will never open.

 

Thank you, I thought it was bad but just wanted to make sure. I have never had one go bad before.

Andy

 

Make sure you get the right one. I can't remember off hand if ours positive or negitive pressure but there is a difference.

Jim

 

Getting the correct one is turning out to be somewhat of an issue. The old valve has a white sticker on top that says OEM but it looks like the number was never there or may have worn off.

Would someone happen to have the correct EGR valve OEM number for a 82 with standard emissions?

NAPA online shows several
http://www.napaonline.com/Search/Res...word&Nty=1&N=0

The local NAPA store says they have one type in stock that will replace OEM numbers 1782807 or 17078423.

Andy

 

If it has a white sticker it's probably an aftermarket valve - your guess as to whether it is correct for your 82 is as good as mine. RockAuto shows a couple of different valves for your car...

AIRTEX Part # 4F1025 is listed for w/Man. Trans.; for 17078423, 17082807. They list it at $48.89. Why they have a manual trans listed is beyond me.

They also have a budget one from KEMPARTS Part # 130238 EGr Valve Except AUTO TRANS,OE #17057407, 17084818 [Wholesaler Closeout -- 30 Day Warranty] (Only 10 Remaining) for $24.79

I'm not sure what the difference between a valve for a standard and automatic would be except maybe a stiffer spring on the standard to reduce occilations while the clutch is being pushed in... I dunno.

Good luck!

 

Thank you for the leads on the valve. In case someone else has this issue, according to GM the OEM number for the EGR is 17078423.

Andy

 

This is not always true. Many ifnot all late C3's use a positive backpressure egr which does not hold a vacuum. http://www.asashop.org/autoinc/dec97/egr.htm

 

Great article. Thanx!! It explains a lot. I had a hard time finding the correct EGR. I have several wrong ones

Jim

 

Good reading - however, it stands to reason that if he can apply vacuum AND pressure to the valve without effect, the valve is bad. The article information does not imply that postive back pressure will open the valve by itself without a soleniod or temp switch (or ECU) modulation "Once the control valve is closed, it allows applied vacuum to pull up on the diaphragm.".... no?

 

Once the control valve is closed, yes vacuum will pull up the diaphram, however the control valve will never be closed "With the engine cold and not running" as noted by the OP, in such a case the EGR will allow air in or out.

All I am saying is, simply applying a vacuum to a positive backpressure EGR is not an effective test to determine if it is still good. I bought several myself until I discovered there was a difference.

Your comment that "Yes, your EGR is bad. If it doesn't hold vacuum it will never open" is 100% accurate when dealing with a single diaphram EGR valve, it isnt as accurate under the testing conditions mentioned by the OP is all.

 

As it turned out I had to order a EGR valve from NAPA so as soon as I get it tomorrow and install it I will post the results.

I have been chasing a code 44 error that came up about a week ago. I replaced the O2 sensor (easy thing to try) but the code still came up. I followed the troubleshoot procedures in my GM shop manual, searched this forum for code 44, and it seemed to come down to a vacuum problem. As a test I plugged the vacuum line from the intake to the PCV valve and the error 44 did not come back. That told me it was indeed a vacuum issue. I have checked the bolts around the intake manifold and all seems good, the brake cleaner sprayed around the manifold and TBI’s with the engine running showed nothing. I also checked all the vacuum lines I could find. The only suspect part I could find is the EGR valve. I hope this is the problem, we will see.

Andy

 

Its a lean condition sensed by the O2. Your O2 is still sensing a lean condition. Try the EGR. I'm not sure that will be the problem but you never know. If you start the car and push up on the diaphram from below it should bogged down and almost stall.

When you have it off. Use some decarbonizer to clean the port in the manifold. That should wind through to the passenger side TBI. There is a little pin size hole under the throttle plate in that TBI. It has to be clear.....I guess this could cause your lean condition....

I started my car after spraying decarb in there with the EGR of I started the car. Look out!!! The decarb liquid and carbon come flying out pretty fast. Cover the EGR opening with a cloth if you intend on doing this. If your port is clear and not clogged it should sound like a massive exhaust leak on start up.

Let us know how you make out.

Jim

 

I finally got the EGR valve replaced and it did not correct the code 44 problem, back to the drawing board.

As far holding a pressure or vacuum the new valve works the same as the original one did. The valve will not hold either pressure or vacuum so the test I was doing is invalid.

In the cut sheet that came with the valve it states “Due to the internal design a vacuum pump bench test is meaningless if performed on this valve”.

Andy

 

Is the port clear? did you try starting the car while you had it off...it should have been real loud? Secondly I you blep the throttle does the diaphram rise?

If that all doesn't work out. You will need to provide more information. Whats the idle at? Is it stable. Any hesitation on excelleration?

Jim

 

Jim,

Sorry it is taking me so long to reply. When I removed the old valve I was surprised at the lack of carbon buildup. The ports had a thin lining of dry carbon powder it looked like. When I cleaned it off it came off as powder not flakes as I would have thought. First I used a shop vac to remove all I could see. I did crank it with the valve off and got a blackish brown cloud for about one second that went to the garage ceiling, also yes on the loud exhaust sound. I do not know if this could be the reason for the lack of buildup but I do use Seafoam in the gas every fifth tank.

The new valve works as it should with the diaphragm does move under acceleration. I suspect the old valve was working properly also.

It typically takes between 11-12 miles for the CE light to come on. Most of the time it is predictable.
It seems to happen when the car is run at a low speed for or idling for a couple of minutes, red light or coming into a subdivision.
Even with the CE light on (code 44) after being ran, when I back it into the garage there is a smell of the car running rich. The slight smell of a engine flooding but it still runs smooth
The car always seems to run good for a engine with close to 170K miles on it. I bought it in 97 and while I have had it the engine has not been into anymore than valve cover gaskets. . If you pull the oil cap with the engine running there is no blow by that you can tell.

One thing I did not tell you was the catalytic converter was gutted last summer but this code 44 started around two weeks ago.
The O2 sensor voltage and other checks according the GM shop manual test good with the exception of the fuel pressure which I have not checked yet. I replaced the O2 sensor just to make sure.

What I do not understand is around a year ago the motor started idling high, started with just a couple of hundred RPM and quickly got worse. I found several bolts around the upper plenum (intake) was loose. After tighten them the idle returned to normal but I never got a CE light on during that time. I have to wonder why I am getting one now with idle normal?

I am beginning to think I need to go ahead with a total rebuild or a crate engine due to the age of this one. I do have front and rear seals leaking a drop or two when I park it but I figure it is just marking it’s territory. It will be a few days before I can get back on this problem but all suggestions are welcome and appreciated.

Thank you,
Andy

 

The stock 02 will not work propery with a gutted cat. The 02 sends a signal to the ECM to adjust fuel air mixture. They say if you go duals or gutted cat you need a heated 02. That could be problem one. They do sell heated 02's for this reason. Stange that it took a year to trip a code 44.

It sounds like your problem is minor. You could chase it for a while tough.

Try changing to a heated 02 first.

If you had a big leak in the top plate your RPM should have climbed to about 750 or higher at idle. The ECM should bring it back to 550 in gear but the car will not run right if there is a vaccum leak. The ECM will continue to try compensating for too much air in the mix.

It could also be the fuel pump. I chased a similar problem for months and thats what it turned out to be. Thats not a cheap fix....couple of hundred bucks if you can do it your self. You need to eliminate everything else fist though. It could also be the rubber hose on the fuel pump in the tank.

When you turn the key to on you should hear the pump kick in...buzzing sound from behind you for about 2 seconds. Followed by the prime pulse from the injectors...another noise for a second. The pump has to maintain a constant 9-12 psi or the system will not work right.

You need a fuel pressure reading between the TBI's. Thats where it counts. The problem for me as getting the parts to make something up between the TBI's. Expensive. So I order one put together by one of the guys over on the crossfire forums site. http://www.crossfireinjection.net/

Try the heated 02 first.

Jim

 

That is worth a try. A quick search of Ecklers, NAPA and Autozone did noty show a heated O2 sensor for a 82. Could someone please point me in the right direction or a link? I am guessing going to a heated sensor will require 12VDC run to the sensor?

Thanks,
Andy

 

Try this site. these guys mention it from time to time.

http://www.crossfire.homeip.net/

 

I found the part number and a cross to other manufactures.

3 wire heated o2 sensors cross reference.

AC Delco: AFS-74

GM: 25312179

Borg Warner: OS120

Bosch: 13077

Now hopefully I can get it wired correctly.

Andy