Negative numbers in fuel trim means rich, not lean. -50 is VERY rich (probably the limit of what can be displayed), so the smoke coming out makes sense. When under load, the engine needs the extra fuel, but when the load is removed, it makes things very rich. You say you replaced all four injectors. OEM? Correct part number? Were you getting these symptoms (very rich, smoke) before replacing the injectors?

 

thanks for the correction it makes a lot of sense now. I am unsure of the part number id have to go look at the box but before were after market generic injectors which were doing the same things as these OEM style injectors are doing. I didnt have these issues until after the rebuild before it ran like a cherry even with a blown headgasket now all of the sudden its doing this. I had my boss at my job double check my work and he says everything is good regarding timing, compression, and oil pressure. When replacing injectors i did not replace the injector harness but i dont believe that would make a difference in this situation. Also it still smokes a lot even under heavy load. I unpluged various sensors to see if it would act different and ive unplugged all but the knock sensor one at a time and nothing changed. If it makes a difference i also do not have a catalytic converter and both O2 sensors are present. Once again no codes or anything it wont give me any sort of hint except the rich running. Thanks for the help btw!

 

According to the FSM, the ECM regulates the injector pulse (amount of fuel delivered) based on engine coolant temperature (ECT), manifold absolute pressure (MAP), and throttle position (from TPS), in all modes of operation -- start, open loop, closed loop, idle, WOT, etc. If the engine is running very rich, it's either the injectors or the ECM that is controlling the injectors. For the injectors, check that the fuel pump is delivering 50-60 psi. Each injector should ohm out at 11-14 ohms. And there is a tester called a fuel injector balance tool that checks injector output, but this is pretty pricey -- you can check with a shop if everything else checks out to have this test done. And because the ECM relies on ECT, MAP, and TPS, make sure each of these is good. If your scan tool reads atmospheric pressure, it should be reading between 96 - 104 kPa (13.9 - 15.1 psi) at sea level with the engine off. (Pressures will decrease slightly with altitude.)

I've not had any drivability issues at all with my 2.2, so I learned a lot looking up this information. Good luck on running down the issue and correcting it.

 

Thanks for the info ive given it a good look over and i am thinking of taking it to a master tech i know to look at it but from what ive seen and the fact those are new injectors and the old ones did the same thing im going to assume the ECM is the issue i can read everything and everything checks out on the scan tool and from what ive tested electrically so it seems i may have a failing ECM which is unfortunate. Any idea if it needs to be programed or if its PnP?

 

I'm pretty sure it's not PnP. It would have to be programmed with at least your VIN so all appropriate systems and accessories are covered, and I think they have to put in the mileage also.

 

I have had a fuel pressure regulator cause extremely rich conditions. The fuel pressure would spike to 100 psi and the car would be over rich.

 

I'm sorry, but the air-to-fuel mix must also depend on the front O2 sensor. If the sensor is there, it doesn't seem to be sensing any oxygen so I would get the reading off that. I'm thinking it's near zero. That would tell the ECM to richen the mixture.

If you don't have a cat, you probably don't have any back pressure either in the exhaust, which means the exhaust will not spend enough time around the front O2 sensor for it to read properly.

Did you have a cat before you started the rebuild?

Suspect the ECM as the last option.

Andy's comment about the fuel regulator is something you must check. There is a Schrader valve on The fuel line leading to the fuel rail. Hook up a fuel pressure gauge. The average fuel pump will put out 90 to 100 PSI into the regulator which brings it down to the 40s or '50s. The regulator for these third gen cars is integral to the fuel filter. So checking fuel up by the engine will tell you if it has failed.

Is there anything else about this build, component-wise not on the car extra on the car etc, that you have not told us about? Does it have a muffler or is it straight piped? Are you bypassing anything? Have you adjusted anything on the throttle body?

Please share the information now so that we may help you. Otherwise we're chasing a ghost with three arms, two heads, and an ****

 

You're exactly right if the ECM is operating in closed loop mode. While still in open loop, it disregards input from the O2 sensor. I didn't mean to imply that ECT, MAP, and TPS were the only sensors the ECM used to calculate injector pulse width, just that those sensors are used in all modes. I read the original post to mean he is experiencing the issue at all times the engine is running.

But I defer to your experience and guidance.

 

No, you are exactly correct. It ignores 02 sensor reading in open loop since the sensor is usually not heated up yet. But he would definitely get a code for not being in closed loop after x amount of time, one would think. Something like a failure to reach closed loop operation. No I have to look up what constitutes closed loop. Keeping me honest, sir.

 

Here we go

Open/Closed Loop Operation

Open Loop

When the engine is first started the system goes into open loop operation. In open loop, the ECM calculates the Air/Fuel ratio based on inputs from the coolant and MAF sensors. The system remains in open-loop until the following three conditions are met:

• Coolant temperature above 105°F.

• Oxygen sensor has varying output voltage (indicating it is hot enough to operate properly).

• A specific amount of time (preprogrammed into the MEM-CAL) has elapsed.

Closed Loop

When all of the above conditions are met, the system goes into closed loop operation. In this mode, the ECM calculates the Air/Fuel ratio based, mainly, on input from the oxygen sensor and maintains the Air/Fuel ratio at the desired 14.7 to 1.