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car running rich

Posted: Tue Mar 22, 2005 3:43 am
by inbed79
hi
can any one help my sportrak 1993 efi is running rich
black smoke
i have replaced the oxygen sensor
the car has no malfunction codes in the ecu's mem

any help please

thankx

Posted: Tue Mar 22, 2005 7:45 am
by murcod
Have you had the fuel pressure checked at all (while it's running)?

Posted: Tue Mar 22, 2005 9:47 am
by inbed79
no murcod i have not
how do i check that?

thankx

Posted: Tue Mar 22, 2005 10:32 am
by murcod
You'll need to find (or borrow?) a fuel pressure guage with a Banjo type fitting. Then undo the fuel line on top of the fuel filter and fit it ( careful there'll be pressure in the line. Alternatively you could get an 8mm "T" junction and cut into the fuel line and run the guage off that (and rejoin it later with a barbed joiner.)

You'll need to measure the pressure with the engine idling (ie lots of vacuum in the manifold) and then just with just the igntion "ON" (ie. no vacuum).

It should be higher with no vacuum- the specs are in the Service Manual.
The fuel pump will run for a couple of seconds when you switch the ignition on- should be enough to get the reading without the engine running. There's also a way to get the fuel pump to run without the ignition on via shorting out a link in the diagnostic plug IIRC?

Posted: Tue Mar 22, 2005 5:41 pm
by lay80n
Check the fuel pressure reg. Make sure that it is not leaking. When the engine is running at idle, pull the vacum line off it and check that fuel is not pissing out.
Layto....

Runnin ya car rich will also screw ya catalitic converter as well as other trouble, so best to look at it.

Posted: Thu Mar 24, 2005 2:59 pm
by inbed79
hi all iam finding it hard to come across a fuel pressure guage
i have pull the vacum line off no loss of fuel
i have checked the water temp and air temp sensors both seem fine
when it ticks over no black smoke but if you rev it then thery is
if i pull the plugs of the air temp/water/tps/ then i get a code on the ecu
but if i pull the oxygen sensor plug of i dont get any codes on the ecu
is this right? could it be that i have a broken lead from the oxygen sensor
to the ecu could it be the injectors

thankx

Posted: Thu Mar 24, 2005 5:22 pm
by lay80n
You could check the readings from the O2 sensor. When its warmed up (the sensor) it should cycle between .1 and .9 volts if working properly.
Layto....

Posted: Tue Mar 29, 2005 6:23 pm
by murcod
Have you checked that your oxy sensor body is earthed? They don't always log faults if disconnected or the earth is open. ;)

Posted: Wed Mar 30, 2005 11:03 am
by inbed79
hi all
have you's had a nice easter

the earth is fine
but how good are these universal 02 sensors

i put a universal one on (new) and the volts was running
at 0.78v when the engine was at running temp
volts was not moving much so this can not be right
i had a spare 3 wire one (new) so i have tryed this
just using the one wire and now the reading
is up and down when it gets to 0.80v it drops
back of to 0.20v and back up to 0.80 average
when the car is ticking over
i have road tested it is runnig around the same
i know its burning a litle oil no smoke until
3500 revs (blue) but if i hit the throtle hard and let go
it chucks out black smoke over rich
i have had a emission test done co and hc are high
it looks like the 02 sensor is attempting to compensate
for the rich mixture now it was not before

does any one in the uk know were to buy a applause 02 sensor
apart from daihatsu all i can find are these universal ones

thankx