Mechanics

CHECK ENGINE LIGHT 25,26, AND 71.

1995 Toyota Camry • 257,000 miles

I already replaced of new Distribtor system, ECU, MAP, Idle control solenoid, coolant temperature sensor, spark and spark wire, ignition module. Anyway, my car seem no good idle and misfire, but it drive as speed very good after blue smoke gone few second (valve stem leaks bad). So, how do I test the fuel injection, 1 heat oxygen sensor and 2 oxygen sensor? I allways looking for scanner test. But 1995 Camry had no scanner of OBD2 plug, it a Diagnostic system not easy way to test. It like no reading live Data information, only trouble read code. I hate that, and I can't find clue of engine idle rough still.
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Iancarvalho
October 3, 2012.



Intake valve clearances are withing specs but for exhaust, # 1 and ! 3 are out of specs.

KHLow2008
Dec 8, 2012.
Wow, I never seen like that of my car's no adjustment valve, same like a Honda motorcycle's engine. Why Toyota made 5S-FE engines without valve adjustments? Only shims can replace for different size.0984" to.1299". So, I will reduce size for adjust. I must remove shims to measure size to reduce for valve clearance.

Tiny
Iancarvalho
Dec 8, 2012.
Clearance adjustment is by changing the shim thickness and this is the way it is designed to be adjusted. This system requires minimal maintenance and valve adjustment is seldom required.

Each design has its advantages and disadvantages. Even hydraulical self adjusting system has its problems so I would not fault it on Toyota.

KHLow2008
Dec 9, 2012.
All right, this is time for not easy to find anything what wrong with Toyota Camry. I done to change current size of valve shim. Then to start engine few minutes, idle seem look good for high rpm for cold start engine. So, I drove the car, few minutes smooth and then stop at stop sign. It still misfire idle few sec, then no misfire 5 sec, and agian misfire few sec. I don't know why these car go same things, I done to replace valve shim already. Last night, I saw the engine light come out one time, it say Code 71. My god, why? I already cleaning and EGR seem good seal and took off EGR valve out of unplug nothing on mount of air intake body plus block the hole with plate with test idle still same things. It misfire something.

Tiny
Iancarvalho
Dec 18, 2012.
What you have now seems to be the code 71 causing the intermittent misfiring.

Code is set when EGR gas temperature is 158°F (70°C) or less for 50 seconds when engine coolant is 176°F (80°C) or more. Possible causes are: l EGR gas temperature sensor open circuit.
L EGR VSV open or short circuit.
L EGR vacuum hose disconnected.
L Clogged EGR passage.
L ECM.

KHLow2008
Dec 18, 2012.
I look online of many people of world, they do have problem same thing happened to me, that reason why I trying to find out what with Camry's engine wrong. Look and read online.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
"Well. I love my Camry. But the engine light has been on forever now. The code reads Exhaust Gas Recirculation, but I had a mechanic check it and say it works fine."

There isn't anything wrong with the car but the check engine is definitely annoying. Also it seems like a common problem among Toyotas. Replacing the EGR valve doesn't seem to solve it.
- Omar R, Kanata, Ontario, canada

Tiny
Iancarvalho
Dec 21, 2012.
There are 5 possibilities as listed in my previous replies and any of them could be the cause.

Not many mechanics are well versed in this systyem and don't even know how and where to start so it is not surprising that the problem is not resolved.

KHLow2008
Dec 23, 2012.
1. EGR gas temperature sensor was a wrong measure of ohms, Failed. Too early 150' degree at 4 ohms reading. That must be over 300' degree at between 2-4 ohms.
2. EGR VSV was good voltage, but still not good and clog so bad inside of air flows from E to port G, Failed and stuck in holes.
3. EGR vacuum hose was all good connection hoses with all current lines.
4. Clogged EGR passage was clean all the parts done.
5. ECM was replaced at last year.
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I already to order the EGR gas temp sensor, VSV switch and EGR Modulator too. Because EGR Modulator very bad cloged too. Wow, it so crazy problem of Toyota techonlogy as grasp !

Tiny
Iancarvalho
Jan 2, 2013.
The VSV should be initial cause and start of the problem. When vacuum is not available or insufficient, it can cause a lot of problem.

This is not Toyota technology alone, almost all other makes have a problem with or are difficult to diagnose emission controls, especially for the earlier pre-Y2K models.

At least we are getting somehwere and the answer should be close.

KHLow2008
Jan 2, 2013.
Happy New Year.

KHLow2008
Jan 2, 2013.
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