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Discussion Starter · #1 ·
Hi,

I don't run EGR on any of my hot rods but I do have it working on my wife's daily driven rice burner, (1.0 liter 16 valve Suzuki Alto) the thing is that it has began to ping badly latelly, I have checked everything and the only cure seems to be premium gas, it used to work fine with regular and I don't want to pay for premium everyday.

The only thing besides lowering compression that comes to my mind that will reduce or eliminate pinging is blocking off the egr passageway, we don't have emissions laws here so it won't matter.

The ECM will not know if the egr is blocked off, there is no feedback for it.

I already have the head off and my hands itch to grab the dremmel and grind off some aluminum to lower that 10:1 compresson ratio, but it used to work fine with regular before, besides there is not much to grind, the 4 valves use pretty much all the combustion chamber's room, there is a very small flat squish quench area, not much to be gained if I grind it off...

the question is, egr mixture dilution increases pinging with low quality fuel or diminishes it.

please comment.

thanks

Augusto.
 

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Discussion Starter · #2 ·
it is working, I can see traces of spent gases in the egr passageways, and the valve's diaphragm is ok and the stem moves freely.

if it helps, why mostly everybody wants to disconect it? of course for top engine performance I don't want it but for a dayly driven conmuter what damage could it make?

doesn't diluted mixtures with egr gases burn slower thus less timing lead is needed?

Augusto.
 

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a lot of people see them as 'emissions devices' and so they arn't nessasary.. EGR's replace some volume in the intake with inert gas. it doesn't re-burn, but just takes up space.. this in turn lowers the cylinder head temps and thus reducing NOX, and pings
 

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Augusto said:
Hi,

I don't run EGR on any of my hot rods but I do have it working on my wife's daily driven rice burner, (1.0 liter 16 valve Suzuki Alto) the thing is that it has began to ping badly latelly, I have checked everything and the only cure seems to be premium gas, it used to work fine with regular and I don't want to pay for premium everyday.

The only thing besides lowering compression that comes to my mind that will reduce or eliminate pinging is blocking off the egr passageway, we don't have emissions laws here so it won't matter.

The ECM will not know if the egr is blocked off, there is no feedback for it.

I already have the head off and my hands itch to grab the dremmel and grind off some aluminum to lower that 10:1 compresson ratio, but it used to work fine with regular before, besides there is not much to grind, the 4 valves use pretty much all the combustion chamber's room, there is a very small flat squish quench area, not much to be gained if I grind it off...

the question is, egr mixture dilution increases pinging with low quality fuel or diminishes it.


please comment.

thanks

Augusto.
I read your other entry about residual exhaust gas being present; but your symptoms are classic for EGR valve failure in the closed position. This results in a loss of inert gases which volumetrically is replaced by air, Air needs fuel, the ECM may not know the failure and doesn't add fuel to bring the mixture back to correct from lean, so you get pinging.

Bogie
 

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Does the pinging go away at full throttle? EGR normally does not function at full throttle, so the part-throttle-only pinging is kind of diagnostic for EGR problems.

Sometimes the EGR valve is, or seems, OK, but a passage will be clogged with exhaust deposits, and the exhaust gas can't get through , and the car will ping at part throttle, mimicing a faulty EGR valve. If that's the case, drill through the carbon deposit, or wallow it out with a small screwdriver, whatever it takes to open up the passage.
 

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Discussion Starter · #6 ·
yes pinging is at part throttle, usually worsens when driving uphill which is the usual here, our lands are not flat at all, I must downshift to reduce pinging, if I just floor it the engin sounds like it's going to blowup.

I thorougly cleaned the head and manifolds today but there were no clogged pasages, there was some carbon buildup in the combustion chambers and piston crowns, the intake manifold was very very dirty ( I wonder if this carbon and wettish sooth came from theEGR? )

I'm definitelly considering lowering the compression ratio, what do you guys think?

Augusto.
 

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Hates: Liver. Loves: Diesel
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Quick recap even though most of this was covered. EGR lowers NOx emissions by sending some exhaust back into the intake. It only functions at part throttle, so it doesn't affect peak power, or idle quality. The reason people think its evil is because they are still stuck in 1970. For 40 years, people have blamed low power on emissions equipment and those terrible "miles of vacuum hoses." The truth is, low compression and tiny cams are what made low power. That, plus the change from gross HP ratings in the 60s to SAE Net HP ratings in the 70s made hotrodders think the sky was falling, and they mistakenly blamed it on the new complexity of equipment under their hoods.

You can alter your wife's engine, but it will be a band-aid fix. The bottom line is that its pinging because something is wrong. Completely altering the engine for lower compression is not the solution. The solution is to fix whetever is causing the detonation. EGR is a likely culprit. The EGR valve gets caked with carbon and ceases to properly operate. Sometimes it stops opening, other times it won't close. If its not opening, it will cause what you describe. If its not closing it will cause terrible idle and part throttle surging/bogging. Suzuki spent lots of money engineering that engine to work right, so altering it to mask something that isn't working isn't the issue.
 

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Discussion Starter · #9 ·
Ok guys, I think I've found te problem, the EGR isn't it, everything seems fine and I'm leaving the engine alone, just the way mr Suzuki designed it, those tiny engines make 65 hp out of only 1.000cc, about one quart and goes 42.5 miles for every galon of gas in city trafic.

I realized that my daily driven 4.0 Explorer was pinging as well latelly and mine does not have EGR (it's assembled in Venzuela and didn't come with emission controls) it didn't ping before running on regular gasoline, so I switched today to premium and the pinging dissapeared, I grabbed the phone and called this friend that owns a gas station and he told me that the government (who makes the fuel for all the retailing brands) in a movement to avoid raising the prices of regular gas opted for lowering the quality of it, unbelievable but since we live in a country ruled by "21st century socialist" as* #oles there is not much we can do, well filling up with premium we still can...

So problem found, I'll put the engine together again, and work harder to buy more expensive gasoline.

thanks a lot for concerning and giving me help.

I'll consider seriously F-BIRD'88 's idea of water injection, I own a liquors factory and have 98% pure ethanol wich will do wonders in a water injection system.

Auguto.
 
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