raverx3m

iTrader: (1)

93 del sol d15b7 engine all stock.

the car is running good no noises of any kind.
i took it up to 5-6k few times to check. and it revs up all the way to redline with no funky noises or clicks in neutral.
when i drive on the freeway the chek engine light comes on after about 10-15 minutes of driving.
when i accelerate from 2000 rpm untill about 4k the car has no power and at 4000 it just kicks and starts accelerating normally.
today took it to emissions testing and failed.
at 3000 rpm
the HC was over 200 norm is 100 something
the CO% was over 10 and norm is around 1.3
didnt even test the idle

heres what happened before that.

car threw 2 rods #2 and #3 2 holes in the block.
i bought a block and head that had a bad oil pump.(brearings were shot)
rebuilt that one and replaced the bad bearings(crank wasnt damaged)
it is running smooth no noises from the crank or bearings.
oil/water pumps all seals/gaskets and belts were replaced as well. so its all fresh except for rings and main bearings.
reused the intake and exhaust manifold from original blown engine.


heres my problem. the service manual shows the connector as 1234 pins but its hard to tell which way is up on the diagram.
and they dont list the wire colors.


i tested my O2 sensor green and white open circuit.
i tested the 2 black wires it whows 15 ohm resistance.

so which wires are the sensor and which are the heater?

and what else besides O2 sensor should i check?
(i put new fuel pump, new spark plugs,checked cap and rotor and wires they were within specs, injectors looked ok but havent tested them yet)
could a faulty injector cause such high CO readings?

Former User

The two black wires are for the heater element of the O2 sensor. It's the other two that would cause code 43. Does unplugging the O2 sensor eliminate the performance problem (no power)? If not, then concentrate on the fuel system. Measure the fuel pressure and test the FPR.

raverx3m

iTrader: (1)

strange. because i ran around and tested a few sensors at the junkyard and they all had no resistance on the colored wires but had 15-16 ohm on the black wires.
can they all be blown? i checked like 4-5 different models and even toyotas.
if it was fuel pump the car would choke on higher RPM instead of midrange.

it accelerates fine all the way through if i accelerate lightly. once i step on it a little bit it sounds like a wrx kinda. and then starts moving at around 4000.

almost forgot i retarded the timing a bit as well.

Former User

As I said, the two black wires are for the heater element, which can be tested by making a resistance measurement. Proper resistance is 10-40 Ohms, so your 15-16 Ohm reading indicated that the heater element is fine. However, code 43 would not be thrown by a bad heater element, but instead by a bad O2 sensor element, which cannot be tested by resistance. The O2 sensor is tested by making voltage measurements.

Set the ignition timing to spec and test whether unplugging the O2 sensor eliminates the problem. If not, measuring the fuel pressure is still a good idea because this will also allow you to check whether the FPR is working properly. You also may way to check your fuel injectors.