Compression Ratio, Octane, & Timing

[ZephyrEFI]

Thanks. I did get a reman Cobra MAF, but I haven't been able to start the engine since I pulled the trans out.

Sent from my SM-G960U using Tapatalk

[xctasy]

Looks like your getting everything well taken care of Brad. Hope that helped some. The NSS thing, it was alluded to here.


Uncle Tonys Garage post (Tony de Freo, Evan Smith, Neil and the MM&FF team who with other guys like Steve Colleson and the Freehold Daves street raced these 14.7 sec cars to 13.43 and later 11.19 secs.)

28.09 to 45 minute mark on the video you tube link, you get Bernie G. Wonderful info on how the EECiv was a tight ship of mystery.




https://www.youtube.com/watch?v=HW-QM9mFXPo



"Ask Bernie" Gollick, now in his mid 80's, was Muscle Mustang & Fast Fords (MM&FF) technical guy. He has said it best. EECiv was propriety and difficult.

[ZephyrEFI]

Man, I can't believe people used to (and probably still do) buy a brand new car, take it straight to the track and start smashing regulators and stuff. I remember when I had my '02 GT, I was on Stangnet, and so many people there had all these crazy mods on their brand new cars. That's just nuts. All I wanted out of mine was for it to stand out from the crowd a bit in the looks department. So, I put a shaker scoop on it and a few other Mach 1 style appearance mods. You take a brand new engine design like that, no one knows that much about it, and start slapping parts on and hope you don't break it racing it. That was never me. I couldn't afford the car to begin with, let alone performance mods people had. I'm even to a point where I'd sacrifice just about any power gains my engine might have over stock just so it will run nicely and be reliable! I don't think it will come to that, but if it does...

[xctasy]

When I get back from my marathon run ( i do long distance running) ill post two links...the SBC engine tune hp variance, and the air fuel ratio tune on a Cessna 152. When air fuel and timing are varied, you have percentages of change which give you an idea of how drastically your populated air fuel and ignition advance tables can swing power and torque. These are Lycoming O360 and SBC details but they are very relevant to your work.

When Ford was forced to go EFi, they were forced to get very authoritarian, and the does and don't played right the hands of racers, Australians, and Australian Racers....

Reversed image sorry

https://hosting.photobucket.com/imag...080&fit=bounds



the fact that this is a cheeezeuzbbyytoast shouldnt bother you too much. Yall get over it....


https://youtu.be/HXX4zcPr9IE

[ZephyrEFI]

So, I thought I would post an update here.

Binary Editor, Quarterhorse, and my wideband are all up and running. I've got a couple of short datalogs, if anyone wants to take a look!

I moved the timing back from all kinds of crazy back to 10 degrees, since that's what the computer expects.

I did a base idle reset. I had to turn the idle screw with the engine off because it would NOT start without the ISC plugged in. I had to open it up A LOT. I'd say the idle is around 8-900 now. I'm going to drive it and see if I can get it learning. It wouldn't let me run a cylinder balance test. It gives me a code of 99, which I believe means "EEC has not learned to control idle". It seems fairly happy besides the high idle.

KOEO and KOER both come up with 11s since I turned off the Thermactor/AIR. I've heard the EEC won't let you even run KOER if it's not seeing Neutral, so we must be good there. I found a flag that tells if the NDS on the trans is seeing neutral or in gear, which is cool. I haven't found anything for the clutch pedal position switch yet though.

Current theory is that my fuel system may have some clog issues. It's showing 40 psi at the rail inlet. The trims are a tenth or so off bank to bank. I don't know if that's typical or not though. I'm going to get some more good non-oxygenated 91 and run it. We'll see where that gets us.

[Jack Hidley]

With the fuel pressure showing 40psi, what is the manifold vacuum?

[ZephyrEFI]

With the fuel pressure showing 40psi, what is the manifold vacuum?

I don't know. I see a "gauge" for it in one of Binary Editor's "dashes" but I don't think the parameter it uses exists in an X3Z. Should I rent a vacuum gauge?

[Jack Hidley]

Brad,

For your car, the fuel pressure needs to be set to 39.15psi for the EEC to run the engine correctly. This is the fuel pressure that all of the fuel calculations in the EEC assume that it is set to. You can of course change the actual fuel pressure if you also change the fuel pressure parameter in the EEC.

There are two parts to setting the fuel pressure.

1) If you have a mechanical gauge on the fuel rail, this is going to show the pressure difference between the fuel in the fuel rail and the atmosphere. With the engine idling, this might be around 30psi.

2) The vacuum level in the intake manifold measured at the same time as #1 above. The is the pressure difference between the atmosphere and the intake manifold, where the outlet of the injectors are located. There are several different units that could be used to measure this. You will need to convert those units to PSI, so that they can be added to the pressure from #1 above.

Once you add the pressure from #1 to the pressure from #2, that is the fuel pressure across the injector (between its inlet and outlet). This is the pressure that the EEC needs to know so that when it opens the injectors a certain pulsewidth, it can accurately calculate the amount of fuel that will flow through it.

The normal procedure is to remove the vacuum hose between the fuel pressure regulator and the intake manifold. Plug the intake manifold end of the hose. Adjust the fuel pressure so that the gauge reads 39.15psi. Then reconnect the hose.

[ZephyrEFI]

Admittedly, "40" psi was just me glancing at the gauge to make sure it wasn't WAY off. So, it might be at the right pressure. My gauge is on an adapter fitting at the rail inlet. I'll take a picture of what it's showing the next time I run the engine.

I don't have an adjustable fuel pressure regulator. I swapped to a stock one trying to address another issue. I'm going to the store today though, I will grab a vacuum gauge.

[ZephyrEFI]

Alright, so this is hot idle. We've got 32 PSI fuel pressure and 17 in Hg.





17 in Hg converts to 8.32 PSI. But wait... wouldn't that be negative PSI or something? Add them positive, and you get 40.32, anyway.

So, I know my FPR is stock, but does the fact that some of the non-stock parts I have like the cam that's going to affect vacuum mean that I need an adjustable one?

[Jack Hidley]

That looks correct. 40.3psi.

I really doubt that the fuel pressure gauge mounted on the fuel rail is any more accurate than 1psi.

[ZephyrEFI]

Okay cool, thanks.

I also did a smoke test for vacuum leaks. My EGR valve had smoke escaping after a little while of waiting. I guess that probably condemns it, which is stupid because I bought it new only a few years ago, and have put very few miles on the car since.