G
geronimo
THe brother says its running fine since I repaired it (no
idle...had an air line to the intake manifold that had come loose),
but it is getting mileage like his truck, around 12 MPG. I read out
the codes, and it is only setting a code for "speedometer" sensor.
Well, I really didn't even think that was monitored by the Jetronic
system, as I thought it only provided the signal to the speedometer.
The wires to the differential-mounted speedo sensor were found broken
when I repaired the vacuum leak, so I repaired the connections.
However, the speedometer was still inop....once in a while it starts
working, but not for long. SO I am thinking the bad connection may be
at the instrument cluster, or the speedometer itself is bad.
So I am wondering, since the ECU is picking up a fault with the
speedo sensor, if I am wrong and it *is* a part of the control
system....and maybe keeping the engine from going "Closed-loop" when
up to temperature.
I need to check to see if the engine is maybe stuck in closed-loop,
because that might explain the poor gas mileage. How do I test for
this? Hook up a timing light and see if, after the engine gets up to
operating temp, if the timing is fixed in spite of revving engine,
maybe?
I think he mentioned it eating gas before it went down with the vacuum
leak, actually! It may have never had normal gas mileage since he got
it over a year ago.
Thanks Geronimo
idle...had an air line to the intake manifold that had come loose),
but it is getting mileage like his truck, around 12 MPG. I read out
the codes, and it is only setting a code for "speedometer" sensor.
Well, I really didn't even think that was monitored by the Jetronic
system, as I thought it only provided the signal to the speedometer.
The wires to the differential-mounted speedo sensor were found broken
when I repaired the vacuum leak, so I repaired the connections.
However, the speedometer was still inop....once in a while it starts
working, but not for long. SO I am thinking the bad connection may be
at the instrument cluster, or the speedometer itself is bad.
So I am wondering, since the ECU is picking up a fault with the
speedo sensor, if I am wrong and it *is* a part of the control
system....and maybe keeping the engine from going "Closed-loop" when
up to temperature.
I need to check to see if the engine is maybe stuck in closed-loop,
because that might explain the poor gas mileage. How do I test for
this? Hook up a timing light and see if, after the engine gets up to
operating temp, if the timing is fixed in spite of revving engine,
maybe?
I think he mentioned it eating gas before it went down with the vacuum
leak, actually! It may have never had normal gas mileage since he got
it over a year ago.
Thanks Geronimo