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I believe if a small amount of coolant leaks into 1, 4, 5, or 8 and burns, it will read rich. Too much will put the frame out, but a little bit won’t and is technically adding an alcohol fuel. I’m not saying this is happening. Just throwing that out there.
 

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Discussion Starter · #104 ·
I did use the 1263s3 (previously and now), but this time used RTV on the coolant ports. I notice the ford performance LMR kit comes with those extra water seals -mine did not.

RE Manifold: Saying I ported the manifold would be generous, I matched the head/gasket port per Chris' instructions in his video. I wasn't going for looks and think I achieved a 100 % functional effect.

Just fired it up after re-installing the manifold. I must say - running smoother. Still rich, condition unchanged in terms of O2 sensor output. Interesting accidental discovery just now - I left one coil unplugged, and that bank leaned out from 0.8 to 0.95. Plugged it back in - back to 0.8 on that bank.

Another interesting tid bit - when I change from closed loop fueling to open loop, it idles more smoothly - not sure how to quantify but it's very noticeable. Same thing happens when I modify the injector slope - I can get the O2 sensors to lambda = 1, but it idles rough. In open loop, it just runs like a top - the only thing is O2 sensors say it's rich.

I'm starting to get suspicious of the oxygen sensors.
 

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I did use the 1263s3 (previously and now), but this time used RTV on the coolant ports. I notice the ford performance LMR kit comes with those extra water seals -mine did not.

RE Manifold: Saying I ported the manifold would be generous, I matched the head/gasket port per Chris' instructions in his video. I wasn't going for looks and think I achieved a 100 % functional effect.

Just fired it up after re-installing the manifold. I must say - running smoother. Still rich, condition unchanged in terms of O2 sensor output. Interesting accidental discovery just now - I left one coil unplugged, and that bank leaned out from 0.8 to 0.95. Plugged it back in - back to 0.8 on that bank.

Another interesting tid bit - when I change from closed loop fueling to open loop, it idles more smoothly - not sure how to quantify but it's very noticeable. Same thing happens when I modify the injector slope - I can get the O2 sensors to lambda = 1, but it idles rough. In open loop, it just runs like a top - the only thing is O2 sensors say it's rich.

I'm starting to get suspicious of the oxygen sensors.
after any repairs, I always clear the adaptives.
 

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I did use the 1263s3 (previously and now), but this time used RTV on the coolant ports. I notice the ford performance LMR kit comes with those extra water seals -mine did not.

RE Manifold: Saying I ported the manifold would be generous, I matched the head/gasket port per Chris' instructions in his video. I wasn't going for looks and think I achieved a 100 % functional effect.

Just fired it up after re-installing the manifold. I must say - running smoother. Still rich, condition unchanged in terms of O2 sensor output. Interesting accidental discovery just now - I left one coil unplugged, and that bank leaned out from 0.8 to 0.95. Plugged it back in - back to 0.8 on that bank.

Another interesting tid bit - when I change from closed loop fueling to open loop, it idles more smoothly - not sure how to quantify but it's very noticeable. Same thing happens when I modify the injector slope - I can get the O2 sensors to lambda = 1, but it idles rough. In open loop, it just runs like a top - the only thing is O2 sensors say it's rich.

I'm starting to get suspicious of the oxygen sensors.
1) I win. Mike loses.

2) Unplugging a coil should produce the result you saw. Misfire reads as lean.

3) I would agree with you that the widebands may not be reading properly. Might be fixable with a free-air calibration. They may have gotten calibrated incorrectly last time. Can’t do them in the pipes or even in a garage with fumes.

4) Do you at least see less of a discrepancy bank to bank now after the manifold re-gasketing? A vac leak will cause a lean condition, not rich, so that would be not the cause of the seemingly “rich” condition in general, but it could be the cause of discrepancy between banks.
 

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Discussion Starter · #109 ·
I'm going to verify if the MAF is correct by hooking up my stock MAF. Can anyone verify if this is the correct transfer function for a stock MAF, or know if they varied year to year? Found this one on another forum.

Voltskg/hr
0​
13.6242​
0​
13.6242​
0​
13.6242​
0​
13.6242​
0.571045​
13.6242​
0.75​
18.6936​
0.884033​
23.7631​
1.09106​
32.6346​
1.18188​
36.7535​
1.32104​
44.6745​
1.46802​
54.1798​
1.57397​
62.4176​
1.69092​
72.8734​
1.80298​
82.3786​
1.88989​
90.2996​
1.98901​
100.122​
2.15405​
120.083​
2.31592​
142.261​
2.44995​
161.272​
2.58203​
182.5​
2.69409​
201.828​
2.90991​
243.334​
3.14893​
295.612​
3.35498​
347.574​
3.54395​
399.219​
3.88599​
499.658​
4.177​
595.977​
4.44312​
695.465​
4.76807​
835.509​
15.9998​
835.509​
 

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4,031 Posts
I'm going to verify if the MAF is correct by hooking up my stock MAF. Can anyone verify if this is the correct transfer function for a stock MAF, or know if they varied year to year? Found this one on another forum.

Voltskg/hr
0​
13.6242​
0​
13.6242​
0​
13.6242​
0​
13.6242​
0.571045​
13.6242​
0.75​
18.6936​
0.884033​
23.7631​
1.09106​
32.6346​
1.18188​
36.7535​
1.32104​
44.6745​
1.46802​
54.1798​
1.57397​
62.4176​
1.69092​
72.8734​
1.80298​
82.3786​
1.88989​
90.2996​
1.98901​
100.122​
2.15405​
120.083​
2.31592​
142.261​
2.44995​
161.272​
2.58203​
182.5​
2.69409​
201.828​
2.90991​
243.334​
3.14893​
295.612​
3.35498​
347.574​
3.54395​
399.219​
3.88599​
499.658​
4.177​
595.977​
4.44312​
695.465​
4.76807​
835.509​
15.9998​
835.509​
this is a terrible idea.
 

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Discussion Starter · #112 ·
is there a 6 pin to 4 pin adapter at the maf connector?
4 pin. Why is this a terrible idea? Systematically eliminating variables to root cause a problem I’ve been working on for over a month now.

MAF calibrations are context dependent and it wouldn’t surprise me to learn that there is error at idle for one reason or another. Have you seen the guys that run this MAF in their FF cars and put a metal plate at the front of their filters because if they don’t, they get misfires? Yeah not super confidence inspiring.
In concept, I like the design. Simple, not a bunch of extra parts, quick to assemble etc. And if it works I’ll use it, just going to verify.
 

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  • engine runs well when widebands say it’s rich
  • engine runs poorly when widebands say it’s 14.7, and it gets there by removing lots of fuel from closed loop feedback.

Open loop runs well I assume based on the fact that open loop wouldn’t remove fuel?

I think you’re pursuing the wrong line of troubleshooting. All the above suggests a correct MAF and incorrect wideband reading.
 

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Discussion Starter · #117 ·
  • engine runs well when widebands say it’s rich
  • engine runs poorly when widebands say it’s 14.7, and it gets there by removing lots of fuel from closed loop feedback.

Open loop runs well I assume based on the fact that open loop wouldn’t remove fuel?

I think you’re pursuing the wrong line of troubleshooting. All the above suggests a correct MAF and incorrect wideband reading.
Yes i'm thinking along similar lines - but how to verify? Order new O2 sensors?
 

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Yes i'm thinking along similar lines - but how to verify? Order new O2 sensors?
Try another fresh air calibration in very fresh air. I wouldn’t even do it in a garage. I’d do it outside. If the sensors are in any type of exhaust fumes or propane heater fumes or anything like that, the calibration will be off.
 
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