Ecoscort - 98 Ford Escort ZX2 ecomodding thread

[BabyDiesel]

Oh goodness! I know my write up isn't the best

I'm having a blast driving the car now! Lean burn is... Weird lol. I flip the switch and the power crashes, mpg goes from 45 to 70ish, and I am all smiles! I'm about to go put and drive right now!

Just curious, is my car suppose to stay in closed loop in lean burn?

[pgfpro]

Originally Posted by BabyDiesel

Oh goodness! I know my write up isn't the best

I'm having a blast driving the car now! Lean burn is... Weird lol. I flip the switch and the power crashes, mpg goes from 45 to 70ish, and I am all smiles! I'm about to go put and drive right now!

Just curious, is my car suppose to stay in closed loop in lean burn?

I'm not sure on your setup how Tygen set it up?

On my Talon I can run it in closed loop or open loop. Closed loop only gives me around 17:1 A/F do to the O2 cycling. This can cause a miss fire with anything leaner while in closed loop.

On my Insight, "still to new to me" but I think it runs in open loop during lean burn and drops to closed loop stioch after x amount of time to cycle the CAT to keep it happy.

[BabyDiesel]

Originally Posted by pgfpro

I'm not sure on your setup how Tygen set it up?

On my Talon I can run it in closed loop or open loop. Closed loop only gives me around 17:1 A/F do to the O2 cycling. This can cause a miss fire with anything leaner while in closed loop.

On my Insight, "still to new to me" but I think it runs in open loop during lean burn and drops to closed loop stioch after x amount of time to cycle the CAT to keep it happy.

The setup is a wire soldered into the MAF->PCM wire. This goes into a pentimometer, dividing voltage and sending part of it to a ground. The rest is what the PCM sees. So the PCM sees less MAF voltage than there actually is.

The strange thing is that after 10 minutes or so, the PCM will go into Open Loop. Power will drop off even more, and my mpg goes down quite a bit. The car is more finicky during OL, as in it does not like as much throttle as it does in CL before knocking.

I'm unsure what A/F ratios I am running. All I know is my short term fuel trims are maxxed out at +32%.

[whatmaycome14]

Originally Posted by BabyDiesel

I got a new license plate!




Amazing how it fits the car, even though the letters are blue

That matches my plate!

[pgfpro]

Originally Posted by BabyDiesel

The setup is a wire soldered into the MAF->PCM wire. This goes into a pentimometer, dividing voltage and sending part of it to a ground. The rest is what the PCM sees. So the PCM sees less MAF voltage than there actually is.

The strange thing is that after 10 minutes or so, the PCM will go into Open Loop. Power will drop off even more, and my mpg goes down quite a bit. The car is more finicky during OL, as in it does not like as much throttle as it does in CL before knocking.

I'm unsure what A/F ratios I am running. All I know is my short term fuel trims are maxxed out at +32%.

OK I see whats going on now. So the PCM is thinking the MAF single is write based on the tweaked voltage etc. The O2 sensor is showing lean and the PCM increases the injector pluse width based on STFT at 32% which is max. Did the LTFT ever kick in? I guess it didn't because you would see the STFT go more towards 0.

[pgfpro]

It looks like the PCM is thinking there's a issue with the fuel pump, or injectors, or fuel regulator because the air flow voltage is correct based on the MAF but the O2 always has the last say.

Can you toggle before 10 minutes and let everything go back to normal? The STFT should adjust quickly. Then flip it back to lean burn? Basically make the PCM happy.

[BabyDiesel]

Originally Posted by whatmaycome14

That matches my plate!

HA! I totally forgot you had that plate Zach! We representin' fo' sure

Originally Posted by pgfpro

It looks like the PCM is thinking there's a issue with the fuel pump, or injectors, or fuel regulator because the air flow voltage is correct based on the MAF but the O2 always has the last say.

Can you toggle before 10 minutes and let everything go back to normal? The STFT should adjust quickly. Then flip it back to lean burn? Basically make the PCM happy.

The LTFT.. I can't remember lol. I'll check both the LTFT and STFT tomorrow morning and let you know!

[whatmaycome14]

I think I'm missing the detailed information about what you're doing to achieve LB. I understand the idea of tricking the computer into thinking there is less air than actual going into the engine, but I don't read HOW you're doing this. How exactly are you "bleeding voltage off the MAF sensor?

[BabyDiesel]

Russell, the LTFT are at +16-17% while in lean burn. When the switch is turned off, they go back down to +11%. This is about right since I am running 17 lb. EV6 injectors in place of stock 19 lb. EV1s (11.76% difference).

The STFT are maxed at +32% when in LB. As soon as the switch is turned off, the numbers crash down to -4% - +5%.

Originally Posted by whatmaycome14

I think I'm missing the detailed information about what you're doing to achieve LB. I understand the idea of tricking the computer into thinking there is less air than actual going into the engine, but I don't read HOW you're doing this. How exactly are you "bleeding voltage off the MAF sensor?

I'll have to draw out a diagram tonight and upload it to be absolutely clear. I have a wire connected to the MAF signal wire going into the PCM. This wire runs to a switch that is connected to a penitometer. From the penitometer, a wire runs to a main ground. When the switch is on, it allows voltage to come through the penitometer, which "divides" the voltage. It takes some of the voltage and grounds it out, but sends the rest to the PCM. The PCM sees a low MAF voltage and reduces the amount of fuel injected.

[Focus-Ak]

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