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| Just cleaned My EGR passageways; EGR Question | |
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| Tweet Topic Started: Jun 1 2010, 10:51 AM (1,295 Views) | |
| rmorman | Jun 1 2010, 10:51 AM Post #1 |
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Dangerously un-informed
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Morning all, After reading several posts on the problems with EGR clogging issues, I decided to clean the EGR valve and passageways (I was also hoping to return some efficiency to my motor as it is getting 38-42mpg). Took off the valve and it didn't seem nearly as clogged as some of the posts I read. Took the exhaust manifold off, used the aircraft cable/drill method for cleaning the passageways. Went through 2 x cans of carb cleaner. Put it back together and now I have a couple questions. 1. I read a post that stated that you can leave the EGR valve off and fire the engine to see if you got the passageways clear. However, with the EGR not connected to the motor, the car wanted to rev a little higher than I was comfortable with. I could hear the exhaust port, but no idea if I got the intake port cleared. I THINK it is clear, cause it took some cranking to get it to fire as I assume the intake had carb cleaner in it. Is there any other way to be sure I got it clean? Is it normal for it to rev like that with the EGR off. I also had the air cleaner off which means the pcv valve was open as well. 2. From:http://geometroforum.com/topic/678529/1/
When I depress the diaphram, the car stalls. How much should the diaphram move when I rev it? Mine does not seem to move much at all. The diaphram didn't look to have any holes in it. 3. Of the 2 x ports on the EGR, is one of them "cone shaped"? Meaning does it narrow as it goes into the valve? Next I'll be moving to timing and oil burn issues. Car has 122K on it. Guy I bought it from said he tested the compression and it was fine. I am planning on verifing that. I am burning over a qt/tank. Also, it looks as if the timing is REALLY advanced. (see pic) There is pinging under load. I'll be getting that set as well. What all do I need to be checking to discover the cause of the oil burn? Thanks! Russ ![]() |
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| mwebb | Jun 1 2010, 12:03 PM Post #2 |
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FOG
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..."When I depress the diaphragm, the car stalls. How much should the diaphragm move when I rev it? Mine does not seem to move much at all. The diaphragm didn't look to have any holes in it."... this means that your EGR passages are mostly open to see if the EGR opens when you drive the car T in a vacuum gauge to the vacuum nipple on the EGR diaphragm , use a long hose so you can put the vacuum gauge in the car while driving. drive the car , hot by about 45mph at cruise NOT WOT , the vacuum gauge should show around 5" of vacuum , if yes your EGR system is functioning Edited by mwebb, Jun 1 2010, 12:08 PM.
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| Bad Bent | Jun 1 2010, 06:32 PM Post #3 |
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Facetious Educated Donkey
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Yes, one of the ports on the EGR is cone shaped. It's a Venturi effect that speeds up the air flow. When I started the engine I was able to place one finger near the exhaust port and felt very hot air and the other had vacuum. It was on for less then 10 seconds. You had a vacuum leak so the engine would rev high. Yea, time to move on the timing and while you are at it spark plugs and plug wires. Are they oily? I suspect with as much oil as you use they may be. The wet compression test will tell you something about your rings. If you don't time it today, at least back off the timing a few degrees until it stops pinging. IMHO |
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| mwebb | Jun 1 2010, 09:50 PM Post #4 |
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FOG
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>..." Also, it looks as if the timing is REALLY advanced. (see pic) There is pinging under load. I'll be getting that set as well. "... < base ignition timing should be set to 8 degrees BTDC if the engine pings on this setting , try switching to Top Tier Fuel 87 octane in a geo metro engine with "stock" compression values , never use fuel with higher octane value than 87 unless diagnosing carbon buildup in the combustion chamber... if the engine pings with 87 octane top tier fuel and Base ignition timing is set to 8 degrees BTDC and the EGR is functioning as designed ... try one tank of 93 octane mediocre fuel if the ping goes away , most likely you have extreme carbon buildup in the combustion chamber s search this forum under "seafoam" for the solution Edited by mwebb, Jun 1 2010, 09:55 PM.
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| Woodie | Jun 2 2010, 07:57 AM Post #5 |
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Sounds as if your EGR is working fine, the important test is if it stalls or stumbles when you activate the diaphragm. You can't really get it to move much by revving the engine at rest. EGR isn't going to have much effect on gas mileage but it is a good idea to have it working. Back off the timing just enough to get the ping to go away. Definitely get a compression test, you've got to figure out where that oil is going. It's not helping your mileage or emissions and will kill your cat if you keep on driving it. A quart a tank is a lot of oil use. Don't expect magic, your mileage is not that bad. 95 and newer Metros don't get the mileage the older cars do. I would expect 45 mpg at most unless you do some mods and drive for extreme mileage. |
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| starscream5000 | Jun 2 2010, 08:46 AM Post #6 |
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Got 70 MPG?
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Like moi
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| Coche Blanco | Jun 2 2010, 10:37 AM Post #7 |
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Troll Certified
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Don't you drive 35-45mph? |
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| starscream5000 | Jun 2 2010, 12:08 PM Post #8 |
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Got 70 MPG?
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More like 50MPH |
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| Coche Blanco | Jun 2 2010, 12:14 PM Post #9 |
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Troll Certified
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Just wondering. lol |
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| rmorman | Jun 4 2010, 10:13 AM Post #10 |
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Dangerously un-informed
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Thanks for all the great help!! Would like to get the timing thing settled this weekend, but The Hot Rod Power Tour starts this weekend and the car will have to sit until after that. I'll back the timing off a bit just to stop the pinging. Then get a gun on it ASAP. I'll also check the plugs and do a compresstion check. As I beilieve I read in some other posts, the compression test is done with a warm engine, all plugs out and WOT. Correct? Timing. Warm engine. Jump those two wires. Set at 8deg. Correct? RPM? Cyl 1 on a 3cyl is the one on the pass side? I ASSUME my gun I use on my V8 will work fine? Its a nice digital one. I'll let you know how it goes. Thanks again!
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| Coche Blanco | Jun 4 2010, 10:22 AM Post #11 |
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Troll Certified
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Timing light would work. Yes that's how you check timing. |
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| Woodie | Jun 4 2010, 10:24 AM Post #12 |
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Everything you said there is right, no need for us, I guess. I would just back off the ignition timing until the pinging stops, then get on with life. Some say as much timing as it will take without pinging, some say 8 to 10°, EPA says 5° in order to pass emissions. |
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| rmorman | Jun 4 2010, 10:38 AM Post #13 |
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Dangerously un-informed
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Luckily here in fly-over country, emmissions tests are not an issue. I know a small block Chev likes as much timing as you can put to it. I'm hoping the timing advance isn't hiding anything else. I get the timing and compression check completed, I'll do the Seafoam clean. Bought a few cans extra as my mowers, chainsaw and weed wacker all use it too. Interested to see how much smoke the 1/3 can down the intake produces!! |
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