what would cause the base timing to change
08-10-2013, 08:01 AM
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what would cause the base timing to change
I have a 1990 4runner with the 3.0 and the past week the truck has been starting to bog down on acceleration and the mpg are getting terrible. Two days ago i has driving home from work and i pretty sure it back fired, so i checked the timing. The timing was at 5, while i usually run it at 11. timing belt was done 6 months ago and it has a new distributor, plugs,and wires.
Could this be a problem with the ignitor? the coil all test fine, but i dont have access to a spark test.
the distributor checks out, coils and air gaps are in spec.
the tps resistances or good but i dont hear a change in engine speed when i jump the diagnostic pins to do timing? (this has all ways bothered me)
Could this be a problem with the ignitor? the coil all test fine, but i dont have access to a spark test.
the distributor checks out, coils and air gaps are in spec.
the tps resistances or good but i dont hear a change in engine speed when i jump the diagnostic pins to do timing? (this has all ways bothered me)
08-10-2013, 08:31 AM
#2
Converter getting stopped up? Your igniter won't affect your base timing. Maybe check for distributor shaft play, although I believe that just makes the base timing jump around a little. Set it back to 10 or 11 and tighten the screw down good, and keep on driving.
08-11-2013, 02:44 AM
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Yes the shorting of the connector cuts out input from the coolant temp sensor, tps, and afm so there input does not advance or retard timing. Knock sensor is not on the e2 circuit, which is what is cut out when the connector is shorted.
08-11-2013, 11:49 AM
#7
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Did you check your distributor sensors per the FSM?
If not, that could be your problem. Makes timing jump around.
Reman distributors are known to arrive w/ bad pickups...
If not, that could be your problem. Makes timing jump around.
Reman distributors are known to arrive w/ bad pickups...
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08-17-2013, 07:53 AM
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08-19-2013, 10:42 AM
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ok you might be right i just pull code 22 and 41 off the ecu both the tps and the coolant temp sensor's resistances test fine at the ecu but they have no voltage. All the ecu's powers and grounds check out so im thinking the ecu could be the problem. The fun thing is after plugging the plugs back in after test the tps and coolant temp sensor have voltage now and the codes haven't returned. In the meanwhile i wired a dmm to the coolant temp sensor so i can observe the voltage as i drive it around.
08-19-2013, 04:13 PM
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Sometimes on these old electrical connections, plugging and unplugging does fix the issue... Not sure why. Maybe removes enough invisible corrosion to make a good connection?
08-20-2013, 05:15 PM
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OK code 22 and 41 came back today truck is still getting horrible mpgs and drives like crap.
all the voltages and resistances test in spec so im guessing its safe to say the ecm is crap.
Time to start looking for a replacement
all the voltages and resistances test in spec so im guessing its safe to say the ecm is crap.
Time to start looking for a replacement
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