My 427 SOHC Build..... Finally the time has come!

[cobracammer]

Hey Ross.  2 hours from Cocoa and 3 hours from Orlando.  Why would it run so perfect in closed loop?  If something was off in open loop, wouldnt it also cause issues in closed loop?  Just curious

[My427stang]

Because it doesn't self adjust as much in open loop, it is essentially an electronic carburetor.

The term open loop itself indicates that it is not getting inputs from all the sensors, you can consider it "broken loop" if you look at them all being connected in a feedback loop.  Once it kicks into closed loop, it listens to all the sensors and adjusts.

[cobracammer]

Ok , so let me ask you this.  When you set this system up initially, you have to wait until its at operating temperature first.  Then adjust the throttle plates until the IAC is at about 25.  Then you recalibrate the TPS.

Now assume its ok after warming up ( like it is now)

Now since closed or broken loop doesnt work well (cold start up until it reaches operating temperature), if I make adjustments to the throttle plates to get it to 1000 rpm ( while still cold), will that screw up what I calibrated when warm?  Or will it automatically go to the original calibration settings After it warms up?  Badically, i just want to see if I start changing things when cold so it idles nice, is it then going to screw up the way it runs after it reaches operating temp? 

[My427stang]

So first, I just used the term broken loop to create a mental model, that's not a real term.  It's open loop, like an open circuit.  So when it's cold, it's open, you might have had a typo there, but just to be clear.

Think of it like this, when you close the loop with someone, everyone understands each other.  Closed loop is all the sensors being monitored by the ECM, Open loop (when cold or other odd conditions for some systems) the ECM ignores some sensors

Second, the ability for an ECM to respond is based on programming as well as the limits of the mechanical or electrical parts.  To answer your question about setting cold, it depends.  If you open the throttles too much, then the IAC will not be able to drop the idle low enough.  If you don't open it enough, the IAC may not be able to hold an idle.  If you run too much fuel pressure, the ECM may not be able to lean it enough, if you don't run enough, it may not be able to adequately atomize and also may run out on top.

So, it is critical that you set up the throttle blades the way the instructions tell you front and back, then reset the TPS.  If it doesn't work well, then talk to FAST to see if you should open the rear TB's idle screw, or maybe adjust the front TB's rear plates, or if there is another means.

Additionally, how is cold start programmed?  idle speed - can you see the IAC value to see if it's maxed or stuck closed?  a/f mixture?  Does it have an enrichment shot to help start?  All are different, but unless you are a very lucky person, just adjusting plates to meet cold requirements likely won't help

FYI just to clarify (maybe)  Lets say you have a 1000 RPM idle.  You could do that with 50% of the air coming from the throttle plates and 50% coming from the IAC, or you could have is 10%/90% or 90%/10% in each case the extremes would cause a problem in some certain environment.  You need to know where your setup is supposed to normally operate, both cold and hot, and adjust accordingly.

Likely confused more.....sorry

[Heo]

I don't know any thing about that particular EFI system but....
On a regular Bosch system, You have a Cold start system  that.
Both enriches the fuel and open an air valve that bypass the
throttle blade to give you higher rpm when cold.
If you have the problem you describe with the idle on the older
Bosch system. You most likely have a defective cold idle air valve. 
Ma by that's your problem ma by not

[cobracammer]

Hi Heo.  Nothing like that on the EZ efi unfortunately.  Talking with Ross and doing a TON of reading online to see whats happening.  Also still waiting to hear back from FAST on upgrading to Sportsman XFI unit. 

[Barry_R]

Not wanting to add any confusion - - but my experience with the EZ-EFI systems has not been very rewarding on higher horsepower builds.  I would highly recommend an upgrade to a system that provides more user interface capability.  It will pose certain challenges to learn the program tables, but you'll get a basic understanding quickly, and the ability to tune each spot on the map individually and get instant response is worth every bit of the effort.

[cobracammer]

Thanks Barry.  Working on getting a sportsman XFI system ( hopefully with trade in credit  lol)

Happy holidays everyone!!!

[Leny Mason]

Hi, Merry Christmas, I just ran it a problem on a customer's car and they installed the right O2 sensors's wiring to the left O2 sensor this took me a while  to figure this out. just a thought. Leny Mason 

[My427stang]

I did the same on my 489 when I did the EFI install, took me most of the winter to figure it out LOL

[Leny Mason]

Hi, That's a tough one but the O2 sensor's one was high and one read nothing. goofy Leny Mason

[cobracammer]

Thanks guys.  Only 1 O2 sensorwigh the EZ efi and its on the passenger side.

Still have not gotten a return call from FAST, so I will try them again tomorrow in regards to upgrading to thesportsman XFI.

Thank you all for throwing ideas out.  It helps, believe me 

[Leny Mason]

How does that work the other side may be running rich and fouling it up, sound's like they scrimped in the wrong place, most engines run way different from side to side. Leny Mason

[My427stang]

All the TB injection kits with injectors in the throttle body itself only use one O2 sensor.  Its not like you can isolate the injectors either, they fog as a batch fire into the plenum and the design of the intake determines how balanced it is. 

No doubt some cylinders are lean, some rich, at least compared to a SEFI port injection, but they still seem to work very well

[cobracammer]

Hello All,

Sorry for not posting in quite some time, but it has been a "wild" past 4 months or so.  I feel like I have aged years.  LOL  Anyway, I wanted to bring you up-to-date on the EFI decision.  I have decided to pull the FAST EZ EFI dual quad system and replace it with an upgrade in which, as many have suggested, I will be able to modify and control the system.  I must say, the FAST EZ system came close.  It is a great system (no complaints on the system itself), as it was the engine that seemed to pose the greatest challenges just based on size, cam, application, etc.

I will be uninstalling the FAST EZ EFI system and putting it up for sale on both this site (in the classified Section) as well as on eBay......  Keep your eyes out for that in the upcoming month or so.

On to the EFI I am using as the replacement; I have decided to go with the FiTech power adder dual quad system.  In addition to the ease of install (and lack of real wiring), I spend 2 weeks calling the tech hotline and just asking questions.  After hanging up, I would write down all we had discussed and try thinking of more "what if's" and "how about's".  I must say the techs were very knowledgeable and each time I spoke to someone, they would verify what the previous tech stated as well as patiently answer all of my new questions.  Here is what I found out:

First, and most importantly since I think it's really my only issue with the Cammer engine currently.....  Vacuum!

The FAST EZ EFI requires a minimum of 10" of vacuum to operate correctly.  They recommend more, but they state very clearly that 10" is minimum.  After researching a few of the systems, FiTech's systems will work on as little as 5" of vacuum! 

Another factor is that the FiTech system has the ECU built into the throttle body itself.  This means that there is no harness (same as with the FAST system) to run through the firewall.  The only item that needs to be run into the cab is the handheld controller (which doubles as a laptop uplink so the EFI can be manually dialed-in, if necessary).

I also verified that the FiTech system is both a self-learning system as well as a totally manual system...Meaning you can manually get all the parameters to where you want them, or you can just let it run like the FAST EFI system and let it do all the learning.

The techs at FiTech suggest using the MSD Pro Billet distributor (this is the distributor I have).  I am able to lock out the Dizzy and then have the EFI system control the timing curve...this was another huge plus.

In addition, there are really only 3 or 4 items that need to be wired!  They supply a new O2 sensor, a coolant temp sensor, Distributor connection, and power/ground for the ECU.  Its just that simple. 

We also discussed my Fuel delivery system.  Have a dual pump in tank system, I have way more pressure than the EFI needs to work well.  I will need to retain my fuel pressure regulator (which I am currently using), but it will need to be plumbed up a little differently.  Currently I have the fuel flowing through the throttle bodies and into the regulator.  At the regulator, I have it set to 43 PSI with the FAST system.  From the regulator, it then goes directly back to the return in the tank.  They said with this system, I will need to set the regulator up to have one line in, one line out to the fuel return, and then a third line to the throttle bodies (which is regulated).  I have the 3rd port on the regulator currently fitted with a pipe cap (So my regulator can be configured to work the way they want it plumbed).

Finally, the FiTech system is not only fully configurable in every respect, it even has the ability to control 2 cooling fans separately (not a huge deal, but since I have puller fans as well as a monster pusher fan... another plus).  The way this is sounding, I think I will no longer need the toggle switches anymore to turn on the ECU, Fans, and ignition box.

And lastly (as it just arrived today), I picked up a matching Vacuum gauge to match the other gauges I currently have.  With the FiTech system, you need to tell it how many inches of vacuum you are really pulling.  Since I have vacuum assist brakes and only about 9" of vacuum when Jay Dyno tested it, I want to know exactly what's going on as soon as it starts.  This gauge will also be mounted in the AC vents using the Roush gauge cluster (and match the Oil Pressure, Oil Temp, and Coolant Temp.)

I will be placing my order for the FiTech system in 1 weeks time!!!!  I'll keep you all posted!