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

[My427stang]

I think I'd probably leave the blades open and see if the ECM fixes the a/f ratio  over time, it will adjust a/f to get it to your point, you simply haven't run it long enough IMHO.

A second option would be experimenting with opening both TBs slightly, or just the front, or just the back, and seeing if it behaves differently. 

Honestly though I think you are trying to adjust too soon, if its close, the computer will adjust and look for what makes things approach the desired mixture, then it will write to the base file and try again, and again, and again.

That's the hole idea of learning, if you try to change things whenever it sees something out of range, then the learning function may as well be turned off because it will never get there and you then just have an electronic non-adjusting carburetor.

Best to get it starting well IMHO and then drive it all over town and see what it does.  The goal really should be to stop touching mechanical things and adjust using the hand held (after it is running cool and you have some miles on it).

[cobracammer]

Hey Ross.  That's a good idea.  The Tech actually said even though I have a dual quad, there is a "Primary" throttle body (it actually is the one in the front of my engine and has a vent hole in the top).... and then there is the one I added (which just uses FAST supplied jumper harnesses to tie into all 4 injectors 1 to 1, 2 to 2, and so on.  When I start a new tune (at 13 degrees BTDC, I will crack them open so manually so that the engine starts by just turning the key....  and like you said, let the computer learn.

The other option (Possibly) is to crack the back secondary throttle body open more so that the car starts without touching the throttle.  The TPS and MAP (I believe) are only hooked up to the primary throttle body.  So when I calibrate the TPS, I believe the sensor its learning from is only on the primary Throttle body.  I will have to look at that when I get home. 

Thing is, when I crack the throttle blades enough to allow the engine to start up without touching the throttle, its at a point where it idles at like 2500 RPM.....  I am guessing that it will slowly learn to bring down the RPM to my 1000 I programmed in while at that same time trying to get the correct A/F mixture, but in the past few weeks, that was enough to make the car overheat before it figured it out.  Hopefully with the new radiator and fans, I can let it keep idling like that until it comes down on its own.

I think my intake manifold is a dual plane though, so will having the back throttle bodies open more than the front affect the A/F ratio on 4 of the cylinders (More air to those 4?)

[My427stang]

Well, first, expect that when it is working correctly it will always idle high for a moment and settle.  I do not know of any EFI controller that doesn't do that, hot or cold.  Basically it's a stepper motor for the IAC and after it fires, it eases it down, some are programmable like my EEC-IV but others just do what the company thinks will work for all. 

Honestly its one thing I don't like about EFI, if you want good idle control, most of them don't return to idle like a carb, they ave a little hang time at the bottom

Second, as far as the throttle body and leaning, it really doesn't matter in terms of leaning cylinders nor the TPS and honestly, I think I'd try the secondary TB.  No matter which set of blades you open, some cylinders will be leaner than others, the O2 sensor only looks at the combined mess and adjusts all injectors, so no matter where you add air, it's got variance

The thing to remember though is that extra air is only at idle, as soon as the TPS shows a change, it uses a different table and adjusts accordingly, so a second reason it just doesn't matter

Your idea of the second TB being different is correct, the primary TB will have the TPS, remember, a TPS is based on two voltages, idle and wide open, everything in between that is a percentage of change.  That's why when you calibrate the TPS it just asks for those two figures.  it doesn't care where it is, it just wants to know where closed throttle and open is and then it looks for the difference between those two points.

Therefore, the nice thing about trying the secondary TB is that it will add air without messing up your closed throttle TPS setting and therefore also not require a TPS recalibration with each change.

The MAP is far less critical it just needs manifold vacuum, all it does is judge load after it sees where the TPS is.  TPS with no vacuum, means it's time for the engine to really work, more TPS with some vacuum, still in cruise just high RPM, it's an input to allow it to make a decision

Again though, you are trying to make the car do something without understanding the programming (not your fault FAST hasn't really told us, unlike the more advanced controllers) and without giving it a chance to do its own magic.

Please realize this, change ANYTHING and learning is invalid.  This is not a carb, in this case, you get close and it tweaks from there over time and in varying conditions.  The ECM is looking for cause and effect with trends, when you change a mechanical or timing adjustment etc, what it learned ca be irrelevant and it needs to start over, or at least re-tweak

I know I am being a broken record, but I am hoping to get you to think differently.  I still think like you feel you need to fix something.  All you need to do is get it on the road at this point.  You still haven't got volume and heat through the exhaust to clean up the mufflers, and you still haven't given it any road time to learn. 

We are still at "get it to run cool and then drive it"  the first bite of the elephant, we haven't got by that yet.  I promise, things will get better fast once we can get some road time on it.  We may even have you tweak EFI stuff, but even the engine temps will be different soon, so again, any tweaking or learning is useless now.

If I were in the room, I'd say, stop touching the distributor, stop touching the TBs, and finish the cooling system.  If you don't have what you need to do that, take a nap, or come to Disney and drink some whiskey with me until you do have the parts

One last comment on edit - When coolant temp (temp sensor), idle vacuum (MAP), and throttle positions (TPS) are constant and repeatable to the computer and the car reaches temp AND the car experiences normal use, the computer will start learning and adjusting it's tables based on O2 sensor output and the programming you requested at start up. 

Until you get those things in italics to be stable and then you actually drive the car, you are chasing your tail.  Note the simplicity, stable temp, repeatable idle conditions, and normal use. If you REALLY need to do something, find some belts

[cobracammer]

HHAHA  Thanks Ross.  I most definitely am going to focus on Cooling.  I understand its going to be trial and error for a while... and like you said, its about correcting as I go one item at a time....until there are no more items.

I will post tonight after I get the new radiator, shroud, fans installed and wired, and coolant topped back off.  :0)  I definitely think I have a better understanding of this whole thing (somewhat) being able to talk through it each and every time  LOL  In a way, I am like the FAST ECU....  I may need to hear it a few times over and over, but its all being used to build a knowledge base  :0)

Thanks again!!

[foxlincoln]

Found this link to a mecum auction of  427 sohc stang.It has a picture of the engine with a added on thermostat housing  and hose from the manifold to housing.I wonder if this was common setup. It looks like a bypass hose has been added to the water pump and runs to the housing.                   https://www.mecum.com/lot-detail/WA0615-215133/0/1965-Ford-Mustang-A/FX-Holman-Moody/      Cool car

[Nightmist66]

I couldn't quite see the hose from the water pump to housing, but looks similar to Jay's setup here- http://fepower.net/simplemachinesforum/index.php?topic=23.0.

[cobracammer]

Hey newbie. I think that was added due to the fuel injection manifold. They dont have the waterneck ( thermostat) that other intake manifolds have. Beautiful car. Thanks for posting it

In other news, radiator and fans were waiting for me when i got home. Radiator is about 2.5 thicker than the stock. Fans are a little larger in circumference than the other 2 electric fans. This means they cover the 2 cutouts in the shroud , but also overhand the shroud on the sides 1" on each side. If its a huge deal, i am sure I can seal it up somehow, but ill wait and see

Everything fits, however the fan motors are larger, and now there is no chance of power steering because the belt had to come off for the fans to fit. No biggie i guess

Everything back in and installed. Coolant added back in. Just need to hook up the fans electrical tomorrow and the reset the timing.  Then test!

[My427stang]

Looking forward to the results with the new fans and radiator!

Going to have to figure out something with the PS, any chance you can move the rad forward or offset the fans?

[cobracammer]

Easier if I could use the old electric fans with new radiator?  Then belt would fit. LOL

Otherwise its cutting and welding to move radiator forward. Lol

[cobracammer]

Just finihed up wiring in the fans. Also, set the timing to 13 degrees with the rotor pointing directly at plug #1. I moved the distributor over a fer gears where I can now retard the timing ( clockwise) if needed. Nothing left to do now but try and start it again

[Barry_R]

Easier if I could use the old electric fans with new radiator?  Then belt would fit. LOL

Otherwise its cutting and welding to move radiator forward. Lol

Could you do one of each?

[cobracammer]

Hey Barry,  I could, and the power steering would fit (as long as I put the small fan in front of the PS pump, but then I am not sure it will cool as needed....  I'll explain:

So got back from Lunch, and decided to get right to it.  Just to recap, the fans I wired up to the relay just like the other 2 (More to come on this).  I have the timing set to 13 degrees BTDC and everything snugged down.  Pushed the car out into the driveway (kind of a nice breeze today but still about 90 degrees).

Started over with a fresh tune on the handheld....  Cranked it over (had to pop the gas pedal once to get it to fire)...  once it was running, I ran to the front of the car and used the timing light.  I was a little off on the timing (like 9 or 10 Degrees BTDC so with a small clockwise turn, I was sitting exactly on 13....  car was idling about 1000 to 950 as usual (sometimes it dips down to 700 or so, but I assume this is the computer trying different things, because it always comes right back to the 1000).  AF ratio was right about 13.5 as usual at Idle, and I sat waiting for the temperature to rise... and the thermostat to open to see if I needed to add more coolant.

At 190, the fans again did not come on and it was rising.  I looked at the fuse on the power wire to the relay (20 amp) and it was blown!  I shut the car off....  got a 30 amp fuse.... flipped the toggle for the EFI (because the coolant temp was still above 190, and the 30 AMP fuse blew!  So last resort... directions I found online (not included with fans)...  each fan pullls about 25 amps with full load.  I had these fans wired in together like the smaller 2.  Dont make a 40 amp fuse in the fuse type I have, so I did a little quick thinking and wired one fan to the relay (to come on at 190 degrees) and I wired the other fan to a toggle switch.

Started the car again after a little cool down period and flipped the toggle on (so one fan running)....  wow they suck a lit of air!  I could feel it just looking down into the front of the engine.  Then I sat and waited for the temp to do bad things....  Every now and again, I would see some bubbles in the degas tank and put more 50/50 coolant in there.  Finallly, I had the coolant filled just so I could see there was a tiny bit at the bottom, meaning the degas tie in line to the lower radiator hose was full, but the degas tank was empty (I am curious about the expansion).  Engine ran for about 10 minutes in the driveway, in 90 degree heat....  after 10 minutes, the fan fan controlled by the relay kicked on.  Temperature sat at 192 for a few minutes, then to 195 for a few minutes, and then to 202 for a while.  I wasnt sure how high it would go, but it was definately not moving up into the 220 - 255 range with the one row radiator.

Finally, almost no smoke coming from tailpipe at all,  I revved the engine once, and some sooty stuff came out, but as soon as it went back to idle, no smoke.

Lastly, I pulled it back into the garage running (holy crap it feels like it wants to GO!)  honestly, a little scary.

Shut off the engine, but left the one toggle fan on.....  and wanted to see how full the expansion tank would go.  If you remember, There was almost no coolant in the degas tank while the car was running, but you could see there was some in the hose at the bottom.  If I would have added more while running, it would have sucked it down, but I didnt.

When the car was shut off (with the toggle fan still running on the new radiator, the degas tank filled back up to the half way full mark!  Thats a lot of expansion!!!!  This is why I stopped adding coolant when It was running....  If I kept going, most likely It would overflow when I shut it off.  Dont know about this.

Lastly, I have that Faux radiator shroud (just the top of the OEM one) because it holds the degas tank and the PS reservoir....  this actually doenst leave much room for the hot air to escape after the fans are pulling it from the radiator.  I may try to make 3 little aluminum brackets to hold the tanks, and remove that shroud top.... to free up some space for hot air to escape.

Everything is actually as it should be, and I guess the next step is to drive the car and see if it gets cooler or hotter?

[Barry_R]

Told ya - each Spal fan requires a separate relay.  They are way better than any other fan I have tried - move a flat ton of air, but work requires power and they soak up a bunch of amps doing it.

On my car I have one wired so its on whenever I have the water pump spinning.  The other is on a temperature relay.  If your's behaves similar I'd wager the temperature controlled one will rarely come on once you get the tune up sorted and the engine has some run time on it.  I would consider using the smaller fan as the temperature controlled unit since its secondary - but first lets get you driving.

Sounds like you're getting really close now.   

[My427stang]

I like the idea of one small, one big fan to allow the use of the PS.  I am not sure I'd have one run all the time, not really a need to have it running when the engine is below temp, especially with EFI. The sooner it gets to closed loop, the better, but it is an option. On the other hand, having one fed live with a switch can help between rounds by leaving it on to cool, but IMHO, not beneficial for a street car, just another thing to kill the battery. 

Another good idea is to make sure they come on with the a/c, it really helps compressor temp.  In my car, I run a clutch fan, but I have temp controlled dual electric fans as a backup on the condenser, but more importantly they come on with the a/c.  Keeps the a/c cold in stop and go traffic and more importantly keeps pressure down for the compressor. FWIW, my two fans are fed to a hot thermostatic switch in the radiator, they will run when I shut it down like a new car, but when it cools, they shut off, so no need for me to remember.

I do like what I am hearing on the degas bottle, sounds like you have it working well.  Next time you fire it up, while it's cold, squeeze all the high hoses to try to burp any air bubbles out, Ford even states that in their procedures if not using a power fill.  After a few times squeezing and a few heat cycles, mark cold and hot on the bottle and you are done.

BTW, I am not sure you need to worry about airflow across the top of the radiator, the goal is to get it moving down as much as you can.  Once you get moving the front air dam causes a low pressure area that sucks it to the ground.  It is true that some air flow above helps keep things cool, but it would be better to get some air flow or radiant heat out of the hood if required, with a scoop or louvers.  (You may not need it though, read below)

Way back machine......remember the early posts telling you to coat the headers?  Don't forget, that is going to be a BIG win for under hood heat and overall idle engine temp.  So if the car runs well, before you start fixing it again, pull the headers and get them coated, it may make all the difference in the world.  This was a MUST DO, and still is

[cobracammer]

I guess what worries me (and maybe its nothing), is that even with both fans on, the temperature still creeps up....  not down.  I would have thought as soon as the 2nd fan kicked on, while sitting in the driveway, that it would start going back down so that the fan can shut off.

My father has a Chevy Silverado (like 2006 or something) and its normal operating temp is like 220 degrees.  What should my engine temperature be (and more importantly what temperature should it not go above?>)

Also, I have not forgotten the power coating.  I just wanted to get the last few "bites" done beforehand.  I feel confident now as the initial timing is 13 degrees, computer went through its startup program and I was able to get the idle airflow on target, the new thick radiator with 2 "jumbo" spal fans,  smoke has almost stopped completely coming from tailpipe, and idles at 1000 RPM.

I understand from reading your guys posts that the car will become a lot more reliable as I drive it on the streets and highways, but just wanted to question the safe and normal temps because I will have someone sitting in the passenger seat monitoring the handheld and I want to know at what temps I can keep driving and at what temp I should pull over and shut it off (if it happens).

:0)  P.S., I have not forgotten in all the excitement that I need to drain the oil again and cut open the oil filter.  I will probably do this in the next few days and post pictures of the filament within the filter.