1996 GEO Tracker "EGR" valve???

[jtgh]

P0400-disected

i added my P0400 monitor page today.

i sent gm a question,
what is the actual pass fail points on the MAP ,during the test.
the "guestimate is 6-8 inches HG drop" but no formal spec."

[automated11]

Now I have my TPS issue resolved (no more code) it is throwing 2 P0400 codes, I am going to clean the intake manifold this week. Once that is complete is there anything incommon with both codes that I might want to look out for? As i said before the egr valve works and the valve / metal pipe is clean which only leads me to clean the intake. Thanks for help in advance.

Jason

[jtgh]

if forget does it pass the stall test.?

[deeznutts77]

i just got an obd2 reader today that reads live time and freeze frame. how do i up load to show results??

[jtgh]

sure as my link shows.

if the TPS is lying its booty off , the ECU can not tell if the throttle is steady.
all sensors must be good and no air leaks, in induction or exhaust blockages is the
prerequiste for running the EGR test.


a bad TPS,can:
cause the EGR monitor to FREEZE ( i call it stall) the software just waits forever for you
to stop wiggling your foot (created by TPS noise)
or
the monitor starts and tps messes up the results.


THE egr test is an advanced monitor.
It uses the MAP sensor to detect an exact amount of manifold pressure drop , at the
moment the ECU POPS open the EGR main valve.
it it dont see the exact minimum drop in vacuum( increase in pressure is what MAP does) then the monitor fails.
(drop ,rise, dont let that confuse you, your vacuum gage will drop, but the map shows and increase, that is because IT measures absolute pressure, where a vacuum is 0 inches)
Look at your weather barometer, it works just like the MAP.
WOT = zero vacuum or max BARO MAP pressure.

we think the pressure drop (vacuum) is 6 inches minimum but SUZ does not tell.
6 inches is an industry avg. best i can tell.

Alldata might have the exact num for each car, but they no longer have a single monthly subscription option, so heck with them. "greed"

stall test.
does it pass?

cheers.

[jtgh]

there are other players here.

the TPS is the key sensor for the HOT ROD effect (jack rabbit starts)
when the TPS says to the ecu , the driver is moving that darn gas pedal really fast.

the ecu drops closed loop and gives you enrich mode
This creates extra power and a change in RPM ,upward. (due to richer AFR)
this increase, will wreck any EGR test in progress.
so TPS noise (as all do at end of life) will trash the EGR monitor , and will stop the monitor from even starting.

remember the old carbi accelerator pump? that is what the TPS does today.
and extra shot of gas.

[deeznutts77]

ok got my code reader
idle
map=21kpa
rpm-1560
iat=18c
load val=12.1%
ect=101c
mas=004
tps=007%
wot
map=94kpa
mas=55g/s
tps=100%
these are the readings i get now i wait for light to come back on:-c
no other codes pending or current
got new black and blue sensor for the front of motor think vsv and evap hope it works
any suggestions???

[automated11]

I just got a code reader also but I have a few questions first.

I resumed cleaning the egr system. I got a 1/8" steel cable and began cleaning the manifold. (1996 16v tracker) anyway it only seems to go in about 2 " and I can get it to go any further. Could you explain the exact tract how the cable is suppost to travel? I cleaned the port inside the throttle valve also but a zip tie only went in about 1". If i knew how the things travel I might be able to clean the system better. Anyway after cleaning i put compressed air through the system to make sure there was some sort of flow. I put it in the one side of the intake manifold and it i did have alot of air comming out the hole inside the throttle body (right after the throttle plate?)

On a second note I did a stall test and the engine tries to stall but doesnt at the last minute then idles really rough until I take the vaccume off the egr.

Could anyone give me some more info to see where to go from here?

Here is my scanner info:

DTC for which Freeze Frame was Stored P0400
Fuel System 1 Status Closed Loop
Fuel System 2 Status Not Supported
Calculated LOAD Value 30.98 %
Engine Coolant Temp 192.20 °F
Short Term Fuel Trim - Bank 1 -0.78 %
Long Term Fuel Trim - Bank 1 -6.25 %
Intake Manifold Absolute Pressure 12.44 inHg
Engine RPM 2,349.50 rpm
Vehicle Speed Sensor 25.48 mph

Thanks,

Jason

[automated11]

to the top

[jtgh]

bump.

it only seems to go in about 2 "

where are you inserting this cable?
are you inserting into path "A" Alpha shown below.

as you see it turns 90 degress to left so you must match that and try to get cable
going all way to the exhaust side. (IIRC)