New year same problems...all 8 injectors firing two times per revolution

Nick & George, use the 1986 EVTM on here to see the correct diagrams. Bank fired systems, if I remember correctly, fire the injectors in two groups, on a V8 they are 1458 and 2367. (end 4 and center 4). Not having a bank fired system to experiment with, I can't tell if they fire once per crank revolution or twice.

You should link your other thread here too.

Ok...I may have a theory...I have bought a flat tapped cam of the 351W cause it was recommended me by someone at the fullsizebronco forum while restaurating my 302 to a 347 stroker. But regarding the ignition I still use the distributor and the ICM of the 302...may there there be the possibility, that the 302 distributor/hall/icm is different regarding the signals they send out to the ECU while driven by the 351W cam?

I have seen on rockauto.com that the ICM of 302 and 351W have different part numbers...

ok -the yellow i'm talking about is located on the EEC relay , this wire should have battery voltage on it  all the time . The EEC relay connects the yellow wire  to the red wire giving it battery voltage also when the ign switch is in RUN , but i don't think this is your problem . as far as the EEC relay , the diagram doesn't show where the relay coil connects to on the ign switch , that is -does the relay energize in run or in run AND stunt . When the truck is in STUNT it fires a hotter spark / hikes up the fuel pump and and messes with the timing . maybe somehow something is staying in stunt , this WOULD DEFINITELY cause the problem you are having   In my opinion, i'd start with the ignition switch  

Ford ignition switches love to get sticky

So, now I'm completely confused...EEC realy? Where is this located?
I thought you have meant the ignition control module...

But back to my question before...how is it possible That the 302 and the 351W have different ignition control modules without any differences inside? If there's no difference, why do they have different part numbers?

The HAL sensors have the same part numbers...

Ok...I was wrong...the ignition control module of the 302 and 351W have the same product numbers, comparing the articles from motorcraft....

Is this the relay directly oder the right side of the ECU?

there is a relay , i'm not sure where it would be located, but it is connected between the ignition switch and the ecu.     it is on the schematic diagram you sent me, its right next to the ecu.    Start at the ignition switch, like i said earlier, this sounds like the truck is running in stunt.

Ok. Maybe I can identify regarding to the cable colors...what do you mean with "stunt"? I can preform the KOEO test...would this work without this relay?

I have to bring the kids to bed...after this I will search the relay and check it...

Regarding to all the electronics in this car, I'm wondering why there are so few relays...my 1986 Jeep CJ7 has much more...

I have found it outside directly on the firewall...I have checked the connection to the ecu pin 1 and 37 is given. Also to gnd of the chassis...
20230115_214841.jpg

Cable colors are different to the schematic...

I haven't tested it with connected battery...but as I suppose, yellow is always hot and red was switched with ignition...

As my injectors are working and spitting fuel, the relay can't be defective. Cause if it was, there were no voltage on the injectors...

It was a shot in the dark.  I've seen vehicles get stuck in stunt due to a faulty ignition switch thats why i figured i'd ,mention it.  This sure is a head scratcher

Ok, thanks anyway...
I will post the whole story of my bronco the next hour...maybe it will help to find the failure...

I have bought my bronco in January 2020 in Germany. Some months before it was imported from the USA. I was driving it home on its own wheels for about 120 miles. Nothing noticeable...the car runs, accelerates, brakes...nothing about missing power or something else ..

After coming home I only want do do some slight changes (new exhaust and mainfolds, removing the stock airfilter...). So nothing special...while removing the exhaust mainfolds, I have seen that some ports on the heads were wet...looks and smells like oil...so I had removed the intake mainfold...now the rally had begun...

Everything was full of dirt...you can't see any of the oil drills (I doesn't know that they are there till I have removed the dirt)...

So, off with the heads...no better news...piston tipper on two cylinders...oil pan off...all crankshaft bearings were thrash...

connecting rods...two were bent...

So what should I do? Finding someone who can bore the cylinders...not so easy in Germany...but I have. So alle original part's aren't available...what should I do?
OK...buying a Stroker kit from summit racing...

So in the end I have refurbished nearly everything, regarding the engine. Nearly all sensors new, new cam (From 351W, flat tapped). New coil, refurbished original Bosch injectors, water pump, etc...

Re-wired the injectors cause of bad accessibility for later when i have planed to change the whole wiring harnes into my own system all with double isolated PUR cables...but changed nothing else regarding the wiring harness up to now.

Removed whole EGR-System. Electrical connector is still open. No bridge/jumper inserted...

The only sensor I haven't got was the knock sensor...

After re-building the whole engine I started it, whiteout any problems. No backfile, nothing...sounds a bit curious and smokes very much.  But as i have used much oil to install the pistons nothing that seems unusual...after setting the ignition I have done the cam break-in...

It still runs rich...too rich...much too rich...10 seconds of run and my 1290 Sq ft Workshop was full of smoke...

After many tests, photos and videos, posts in the fullsizebronco forum, I have found  out that all 8 injectors gets shot two times per revolution...

So on my way to solve the problem, I have bought new MAP, distributor, ICM, another set of new air- and water temperature sensors, new throttle position  sensors (3 of them) new idle control valve, new injectors, new fuel pump...

So, you see...I have bought a new car in pieces...

As you see her, in this post, I also have checked the wiring of the ICM to the ECU and some more...

Now, I still have no idea where the "dog is buried"
Do you know this Phrase?

I have been reading along and I understand all the frustration. It seems to me that you have come to the restoration by default not by design. This is not a negative comment just that it happens that way sometimes. From all that I have gathered, it still seems that you have a shorted connection or a made-up connection unintentionally. there should be measurable trigger outputs from the ecu firing the injectors in sequence. bank one, bank two, repeat. each should trigger/fire twice per revolution but taking turns. study the ecu for which wire comes out going to the injector groups. two groups of four each.
very often when troubleshooting I look for the last thing touched and work my way backward. sometimes I find earlier work performed in varied degrees of quality and sometimes I find a mistake that I made myself.
as to the relay in the picture, that may very well be the fuel pump relay as this vehicle should have that along with an eec relay.  usually mounted to a plastic bracket which is also a water shield beside the power brake booster under the hood. don't leave it laying but put it back in its protective position as these trucks are NOT weatherproof.

Testing the pins that fire the injectors from the ECU is definitely an important piece of data.

1. You will be able to confirm the ECU is firing one back at a time
2. It is is firing both at the same time then you know either the ECU is getting bad info or is faulty. I know you replaced it already, but replacing something does not mean it is working.

Following with interest.

Fyi: i will be in Germany next month and have a spare ecu from my 1985 efi. I will be in and around Frankfurt/Nurmberg/Kelheim and would be happy to bring it for you test with if needs be.

Thanks for this offer. That's very nice of you. I have seen that I have forgotten to tell, that I already have a new ecu. One from a 1987 351W. Same failure as with my original ECU...both outputs of the ECU fire together, two times per revolution...

So the ecu can't be the defective device...it's more than unlikely that two different devices have exactly the same failure...


I also have checked that both outputs are not shorten. I also checked the inputs. As described before in this thread, I already have routed the three cable Coming from the TFI with a cable outside the car, directly to the ECU...also no effect ..

My question is, on the base of which data the ecu fires the banks? Only the PIP signal? Is it possible That it's common, that both banks fire together as the car is starting and the alternating fire of both channels begin when the engine is running?
But how does the ECU know that?

It's no so easy for me to search the reason without knowing about the things the ECU performs...

With this information I can start to search for maybe a broken cable...because while unmounted the engine, I have to move the harness from one to the other side of the engine bay...the isolation was hard as a rock...so this is also a possibility for a failure...but I have to know which signal/cable can cause such a behavior of the ecu...

Currently I want to avoid to remove the complete wiring harness...I will do in the future, but for now I need the car get running...

One major item, Ford changed the pin connections on the EEC plug between 1986 and 1987. I sent Gary the pinouts in an Excel spreadsheet located here: https://www.garysgaragemahal.com/electronic-engine-control-eec.html check the input signal and control circuits for the 1986 and 1987 up EEC-IV system.

One in particular, is pin #5, in 1986 it was a 12V key on power source, 1987 on it was eliminated. If the 1987 EEC has an internal connection to this, that might cause a problem.

Ok. Thanks. I will check.

But one question...If have the same failure with the original and the 351W ECU...that's a fact that makes me crazy...as also I have changed every involved part...

OK... I haven't changed the knock sensor...and also none of the relays...i think more and more that somewhere is a broken wire...but which one can cause such a behavior?