Fitech help sought.

Man guys tons to digest here!  
 

well, I can't drive it yet as I screwed up the track bar and just finished welding up a new one.  So I should be able to see how it drives soon. 
 

Regarding using in an older bronco, you do need to do something with the fuel system. They have a fuel command center to allow the use of the stock system which has mixed reviews.  I plumbed new supply and return lines to a new tank in the back with an in-tank pump. 
 

but contact me about a fueL command center and about how to wire the fitech itself up. 
Username at yahoo

Temps here have been about 60-80 and I have bumped up all of the crank enrichment so that it actually starts without ether but may require an additional key cycle or two for an additional prime shot or two. 
 

I'll look into logging but I am pretty excited as I have always wanted to learn more about tuning. 

In the past, someone found a place where we could upload data and that others on the board could download it and look at it.  Does anyone remember that?

edit- it looks like I've gotten some files via google sheets- where you can share spreadsheets.

Otherwise, shoot me a copy of the files- alfa (seventy-three) at comcast (dot) net.  That's where all my PM's go.

When you do a logging, start the recording before you crank.  Need to get a copy of that, and if you can, make sure the WB sensor is running before you start, too.  Dunno if the system will let you, but the odds of you breaking the sensor is pretty small- I've been doing that for a few decades now, and still have not broken a sensor.

Again, the key to tuning is to know what you want, record what it's doing, and figure out how to make it do what you want.

And what you want is it to start as soon as possible, cold idle just rich of stoich, idle as lean as you can for stable idle, cruise at typically 14.6:1 air- fuel, wide open throttle at 12.5:1 or a little richer.  And blend that so that it runs smooth.

In reply to alfadriver (Forum Supporter) :

All of that. But the important thing is to be sure that your efforts to adjust are not band-aids for engine,electrical, fuel or install issues.

I did the in tank fuel pump with a new tank and delivery line.  I used the existing fuel line for the return.  

I have about 2000 miles on mine now.  

I had a fuel pump issue that Summit rectified.  From what I understand the FiTech ECU drives the fuel pump with a PWM signal.  The Tanks Inc fuel pump didn’t agree with that and it failed.  Summit Tech line recommended the pump and gave me full purchase credit on a replacement FiTech in-tank pump.  I also had some EMI/RFI issues that I believe were tied to the cars Mallory ignition system and the tach signal wire.   Ford engines from this timeframes front mounted distributor seemed to be prone to electronic noise issues as the FiTech ECU resides in the front portion of the throttle body. I wrapped the tach signal wire with copper mesh and then a layer of aluminum tape and the issue hasn’t repeated.  I also had one instance of my old school oval air filter element contacting the coil wire on the distributor when the good closed which shut down the ECU until I disconnected the battery and then put things back together with another air filter.  No issues after that change.  

In reply to wawazat :

PWM punp control..... that's interesting.  With the simplicity of the system (which I do view as a posivitve), that's a curious choice.  For all return and most returnless fuel systems, there's no pump control- turn it on, and let the pressure regulators do the work.  And those pumps and parts are all over the place- that's such a simple system, it would be the one I would choose.  

To help with the EMI issue, it also helps to twist the wires.

Odd that FITech uses a PWM fuel pump drive, as very few other (even high end) systems do and even then it's an option. I can see that being more to accomodate a single fuel line/returnless system than a traditional installation. I would check the stupids (sensors all reading correctly, fuel pressure is good while cranking/running, ignition timing is synced in) and go from there.

I cannot recommend a return-less fuel system.

Fuel sloshing in the tank will admit a certain amount of air into the system.

The fuel system needs to eliminate that air or it's only way out is through the injectors. As the air leaves the system through the injectors it displaces fuel and screws with fueling (usually causing misfires).

Using a swirl pot or a return type fuel system is the only way to purge that air. There is a bonus in that a return type system plumbed so the regulator purges the fuel rail of air also recirculates fuel and cools the rail/injectors.

In reply to bentwrench :

Of course, but think about the type of people FiTech is geared towards:  People who want to drop on a solution to replace their carb with a more modern solution.  Which is why the ECU is mounted to the TBI unit and they use a single fuel line, etc.

Not to say you can't or shouldn't improve it using a swirl pot and return lines, etc. but not everyone can fabricate that sort of thing.

Its like the people that can build massively powerful engines, but can't lay paint for crap.  Everyone has things they are good at and things they wish or know they should be better at.

Well, I got it together and after two prime shots it fired up. Went on a 10 minute drive, including full-throttle pulls, decel, stop and go.  
 

it ran great. Shockingly and amazingly great. 
 

got home, pulled in and checked some numbers.  It showed 195 temp, and was idling fine albeit a little above target.  I shut it off, waited a few mins and tried to restart.  It cranked but didn't fire so I tried again and it fired right up.  I really think this thing needs more fuel than one shot offers. 
 

regardless, it was idling for maybe 2 minutes while I was looking through the menu and it just died. Instant   Fired it back up and it started stumbling and died.  I can restart and it fires up great for one second but starts stumbling really bad. with pedal to floor I can keep it alive for a bit but it is crazy rich. 
 

Waited for 15 mins and same thing but watching the afr it shows 14.7 but there is no way that's right. 
 

could my o2 sensor happened to have just taken a massive dump?

i don't have an operational pc right now so I can't get logs.  Ugh.   I'll be working on that. 

I would have a fuel pressure gauge on that thing pronto.  Both for the start condition and the dying condition.

Will it run off idle if you are in the car pedaling the thing?

Pete

I've not seen an O2 sensor die like that, especially that quickly.  It could be that the thing is ignoring that.

How are you doing the ignition?

And did you log it??  You should be logging it every time you start it up.  At least that way you would be recording what is causing it to be running so badly.  

All of our troubleshooting depends on the assumption that your ignition is operating 100% and healthy. Some of the issues you're describing make me think there's an ignition related concern here too. 

In reply to Mezzanine :

If the O2 sensor sees unburt O2, it will have a lean signal.  Seen that by accident before.  Not fast enough to actually detect a misfire, but it won't combust enough to remove hte O2 to detect.   

The real lesson is to record, record, record- which will tell you where the system is having problems instead of guesing.

I appreciate all of the thoughts and help.  I will start logging and hopefully be able to pull them off soon. 
 

I agree that I need to get a fuel pressure gauge on it.  I just ordered one. 
 The built-in regulator is on the return side, which is where I've seen them before. 
would I want a reading from the return side after the regulator or on the supply side?

and yes, it definitely could be ignition as well.  Which is why this is a little frustrating.  Seems more likely that it is this efi but it could be anything.    Whatever it was it happened instantly. 
 

also, I watched the afr more closely on a last attempt and it was reading around 10.5-11.5 before it finally stumbled and died

final thought:  I believe the in-tank pump is a 255lh unit that is not pwm controlled (runs off of a relay that fitech controls).  Possible that it was too much for the unit and something let go?   There was no fuel in the regulator vacuum line. 

here are some pics if they would help.  The return is on the passenger side 

the ignition is a pertronix unit inside the distributor 
 

That's pretty darned rich.  Like close to the rich limit for any combustion.

Randomly shutting down is what I saw when I was fighting EMI/RFI stuff that I addressed by shielding the blue tach signal wire.   Watch the RPM display on the handheld when it starts stumbling and, if this is the same problem I had, you will see an RPM value of something like 51xxx pop up then the car stumble and die.  

Funny about the rpm...

it looked fine on the handheld controller - never read anything like that and seemed accurate at <600 and dropped as it stumbled and died. 
 

but!

i did find target rpm on the dash is set at 50960. I know I set the rev limit At 5500 and it still says so.  Not sure about this target rpm. 
 

Could you see the emi stuff something that could kick on suddenly, after running fine for a while??

again, I know I'm not giving much to work with.  I'm learning this efi stuff

Yeah the odd wildly high RPM value would pop up on the handheld screen and the car would die soon after.  The ECU saw that value as something so far out of range that it shut down. It was a random spurious signal.  I located my coil and MSD box on the inner fender and then shielded the tach signal wire.  After these steps my problem stopped and hasn’t come back.   

That idea has merit as the ECU is right next to the distributor.

Maybe some thick plate temporarily placed between the dist and the ECU might help?

I'll definitely try it. 
 

im dubious however as this problem had a very distinct beginning. 
 

It sounds to me like the fpr took a dump and tons of fuel is getting sprayed in. 
 

Here is a little more thorough description of the current problem:

It fires up with the throttle open, runs up fast like on all 8 and then starts stumbling, have to keep throttle open, stumbling gets worse and worse until it dies after maybe 5-10 seconds. 
Every time it does this.    It will rev up (super roughly) if you pump the throttle but won’t stay running

It sneezed through the throttle body at least once. 

When I get fuel pressure readings I'll learn a lot

In reply to jfryjfry (Forum Supporter) :

Broken record here- log it, record it as fast as it can output data.  That will show where the symptom is coming from most likely.  

BTW, the best solution to the EMI is to get engine speed from a shielded and twisted wire pair from the sensor to the module.

I assume you have checked the handheld for error codes?

ECM that close to the coil is less than ideal from a electrical theory point of view.

 am looking for a ground wire from one of the mounting studs back to the battery, the fitech is very susceptible to poor grounds and the first rule of electronics is that if something behaves as if it is possessed, there is a bad ground somewhere

In reply to alfadriver (Forum Supporter) :

I know, you're right.  I did on the last one.  Trying to see if I can pull it out. 
 

Just curious, do you have it on a circuit that has good 12V power on Start position. I've seen people have issues where the circuit they were feeding the ECM power from had 12V+ on Accessory and Run, but either no power or iffy power on Start. So if they dribbled fuel down the throttle body, it would start and fire, but it would never start without an external fuel source (or it would start, bark once, stall and then crank without starting)