11-11-2021, 06:24 AM
yes you have ECU that is EGR2 level or as we say Calif EGR2 was upgraded on your 1994, so is heat tested to pass test 51, egr. all looks go there.
the tests is simple when you cruise the car, the ecu knows the egr valve is open (some) and then reads the EGRT sensor for hot.(readings) just one test it does not do 2 like 1996up.
that 1 test passing means the valve did open(main) or if not passing valve is stuck closed or the exhaust path via it, is blocked.
if can push the ring EGR ring on the diaphragm and feel it move in 1/4" and the snap back finger off we know the valve is not jammed.
do that cold first, to do so and be sure the EGR main is not brick up, inside packed. as they love to do.
51 is the most common type of failure on this car, and lots of ways to fail. (exh paths, vacuum and electrics to VSV and modulator working too)
do the stall test by hand, or by hand vacuum pump more easy.
if it stalls (or 400rpm) we can then test VSV and Modulator next. to be sure that works, even clogged nipple that feeds vacuum the egr VSV can fail easy, the plenum is nasty there.
that nasty gunk there (is from PCV valve gas could and can clog the EGV VSV valve easy making it useless with gunk
but we test all that.
really the stall test is first, by finger or by hand vacuum pump. to the egr main nipple. that video above shows what happens, super low RPM and engine shacking very hard, at idle
test is on hot engine 800rpm , .
the tests is simple when you cruise the car, the ecu knows the egr valve is open (some) and then reads the EGRT sensor for hot.(readings) just one test it does not do 2 like 1996up.
that 1 test passing means the valve did open(main) or if not passing valve is stuck closed or the exhaust path via it, is blocked.
if can push the ring EGR ring on the diaphragm and feel it move in 1/4" and the snap back finger off we know the valve is not jammed.
do that cold first, to do so and be sure the EGR main is not brick up, inside packed. as they love to do.
51 is the most common type of failure on this car, and lots of ways to fail. (exh paths, vacuum and electrics to VSV and modulator working too)
do the stall test by hand, or by hand vacuum pump more easy.
if it stalls (or 400rpm) we can then test VSV and Modulator next. to be sure that works, even clogged nipple that feeds vacuum the egr VSV can fail easy, the plenum is nasty there.
that nasty gunk there (is from PCV valve gas could and can clog the EGV VSV valve easy making it useless with gunk
but we test all that.
really the stall test is first, by finger or by hand vacuum pump. to the egr main nipple. that video above shows what happens, super low RPM and engine shacking very hard, at idle
test is on hot engine 800rpm , .
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