Topic: Message #1160157

[Jason E.]

I'm no expert on anything but aren't the knock sensor and O2 sensor kinda important-ish to making a fuel injected engine run right? I've been told that a 22RE will not run well without a knock sensor

It ran without a knock sensor. But yes. Not well. Ran brand new wire and sensor this morning

From what I believe the ECU does if the mama ECU does not detect the signals that she is expecting  to get, she's not going to be happy and the question is what is her default position regarding Fuel and ignition timing to that engine when she does not get all of her sensor inputs.

I agree completely. Thats why im back tracking my issues as I see them come up

just to make sure, you said you are running a 93 22re. are you also using 93 injectors, sensors and a 93 ecu?

Yes. 1993 Red Top Injectors, ECU, and Harness

How do you know FOR SURE that it is running overly rich? Backfiring and poping could be from running lean, and the fouled looking plugs could be from the rings not seated. I don't know the spec but if you say your fuel pressure is low, and you run a ported head, bigger cam, header a bit higher comp on the stock ECU it would be obvious to me that it is running in fact lean. You say you are throwing more fuel with the cam and ported head but you are in fact allowing more air, and with a primitive ECU to control air/fuel ratio, it has narrow parameters to adjust, even though MAF (mass air flow) equipped EFI is usually more forgiving of increased airflow. Have you checked for a vacuum leak with brake cleaner or similar fluid? Does the ecu throw a code?

If you are indeed overly rich, the only sensors that I can think of that have a big impact on a/f ratios are, in that order, ECT (engine coolant temperature) and MAF. I donk't think a faulty o2 sensor or IAT (intake air temperature sensor) could make it run that bad. If it's not a sensor issue, it would have to be an injector stuck open (a different looking spark plug would give a clue), or the 4 injectors were damaged when cleaned or since the last time they ran.

Once the fuel pressure issue is solved, if you are not interested and a tunable ECU like megasquirt or microsquirt, I would at least suggest an adjustable fuel pressure regulator to keep the a/f ratio around 12.5:1 at full throttle, and to fine tune the timing. A tunable ECU would however give the best results, bring out the full potential of your build, and give you the best fuel mileage.

Thats great to head. And as you said it might be running lean I started looking in that dirrection. Lone behold you were right. The AFM was not reading as I would up the throttle so It never told the ecu I was getting more air.

What Adjustable FPR would you suggest? I have direct intake supplied to my FPR currently and I dont think it likes it.

With the ecu not getting a signal from the O2 sensor, the ecu will run the engine rich to prevent a lean condition.

When you pulled the knock sensor, did you do anything to full the ecu into thinking the KS was still there?

With you removing the KS and O2, and with just two vacuum lines, pretty much everything else, you should be running a stand-alone ecu.

http://www.lcengineering.com/LCTechPages/fueltech50.html

I would Love to go stand alone and that is my plan. But for now Im going to avoid that dirrection.

I would argue the knock isn't really important in most applications, but the 02 is the single most critical sensor!

I will be installing my 02 this weekend.

Not having the O2 and knock are causing the problem. Quit chasing your tail.
The ecu cannot time properly without the knock.
It cannot control fuel without the O2.

Knock is Installed. 02 will be soon. It cant control it. no. But can run off of a base tune the ECU has stored in its memory.