10.5 afr at 2k cruising speed? Is my ecu shot?

mrhalfwitt

I just got done installing my wideband and took the car around the block just to see what my afr's look like. The best afr I got was 14.12 pulling in my driveway when I just about stalled it. I don't have anything installed to datalog yet but i'll tell you what I did and what I saw.

I'll go rpm and afr under acceleration, Remember my clutch is still slipping so I wasn't hard on it maybe 30% load slowly stepping into it to max rpm.

2000-10.5
3000-9.7
4000-9.4
5000-9.2
6000-9.0
7000-9.0

and cruising 2000 10.5

I was reading the MPG thread and was wondering why i'm only getting 18mpg. Now I know why.

I do have an adjustable fuel pressure regulator set at 40psi, should I lower it?

I forgot to mention it's a dohc ZC and I have no idea what ecu is in there. They told me it's from an accord.

And I have code 6 bad temp sensor and code 9 bad cam angle sensor.

mrhalfwitt

I just got back from the corner store and I tinkered with the fuel pressure regulator. I got my AFR's in check, the pressure was way to high. The problem I'm having now is acceleration enrichments. When I first get in to any gear for the first few seconds it's going as low as 17.0 AFR. Can I adjust the TPS or something to tell it it's under a load? I'm fluttering the gas peddle and riding the clutch for now until I figure this out since I need a clutch anyhow.

ragenasian

Seeing as how you already know you have a couple of issues with the codes you should get those fixed first.

mrhalfwitt

I can get the temp sensor at my local parts store, and from what I read the computer only needs it during warm up.. As for the cam sensor the guy I got the car from who is a honda tech told me I can only get a used one from japan.... with a good luck. I have a megasquirt i want to put on this car and I found most of the resources I need to make that happen. This will eliminate the need for the cam sensor all together.

But for the time being I think my regulator problem will help with my fuel mileage problems. One way to work is 35 miles, there is no way it should cost me $5 one way in a honda civic. I was spending that in my chevy c1500 work truck with a 350.

Jaker

If you have a bad temp sensor, the ECU goes into a limp mode and dumps fuel to protect the engine from blowing up. By dropping the fuel pressure, you've leaned out the motor, and now when you "get on it" there's not enough fuel for the acceleration. It's going lean. Change your bad temps sensor, and change you bad crank sensor (just change the distributor), set your fuel pressure to OEM, and go from there. I'd be willing to bet that your O2 sensor is probably cacked as well if you've been running that rich for any great length of time.

Last, are you 100% sure your wideband is correctly calibrated? What brand is it?

mrhalfwitt

Jaker wrote:

If you have a bad temp sensor, the ECU goes into a limp mode and dumps fuel to protect the engine from blowing up. By dropping the fuel pressure, you've leaned out the motor, and now when you "get on it" there's not enough fuel for the acceleration. It's going lean. Change your bad temps sensor, and change you bad crank sensor (just change the distributor), set your fuel pressure to OEM, and go from there. I'd be willing to bet that your O2 sensor is probably cacked as well if you've been running that rich for any great length of time.

Last, are you 100% sure your wideband is correctly calibrated? What brand is it?

The lean thing is just the first split second I apply throttle going into first gear. Driving it to work today showed me alot. cruising on the highway to work at 4000 rpm doing about 80 mph the gauge was showing 8.6afr. And again another half a tank round trip of 70 miles.

I'm using the oem naw from 14point7.com. I have been using his products for 4 years now and I have never had any problems.

But I will get a new temp sensor, if what you are saying about the limp mode is true that explanes alot.

mrhalfwitt

I just got back from road testing the car with a new temp sensor installed. The code 6 went away and now it's flashing 5 and 9. I see where this is going to lead me.... Been down this road before with the mazdas.

ragenasian

Yeah I have been down that road also, but just check the connections. Little corrosion or a loose wire can throw a code too.

By the way every crx over here had a DOHC ZC so if I can figure out what the part is in German I can probably get a cam sensor for you.

mrhalfwitt

ragenasian wrote:

Yeah I have been down that road also, but just check the connections. Little corrosion or a loose wire can throw a code too.

By the way every crx over here had a DOHC ZC so if I can figure out what the part is in German I can probably get a cam sensor for you.

That would be cool, It's the cam sensor or also called the cylinder 1 top dead center sensor. It has nothing to do with the distributor and is located on the exhaust cam on the trans side.

I tracked down my code 5, it was a broken vacuum T going to the map sensor. My AFR's are in check now. Thank you for the codes and what they really mean.