New member, big problem

[ReneH]

Hi together,

my Name is Rene, I'm located in germany, near Frankfurt. I have bought a 1985 Ford Bronco with 302 EFI inside in january 2022. After driving it about 120 miles home, I want to do some adaptions. Journey back to home was OK, nothing suspicius. At home, as I have removed the exhaust mailfolds, I have seen there is much dirt Inside...very, very much. More dirt than engine.

So, to make it short, I have talked to some people in the Fullsizebronco forum. At the end of this tale, I now have a 347 stroker. Nearly everything replaced. Only the stock heads are still there.

Now, my problem is that after all was mounted, that engine runs very fat...after it runs some minutes, all 8 spark-plugs are wet. The engine starts instantly, runs in idle and also at higher RPM. Not very good, but it runs. After checking many things, I have found out, that all 8 injectors spraying 2 times per full rotation of the distributor finger...I my understanding this explains why so much fuel comes inside the engine.

My injectors are split in two groups. Each group has a direct cable to the ECU and a seperate PIN there.

So I have replaced many other Parts (ECU, TFI, MAP, EFI-Temp-sonsors...) all without success...the last answer in the fullsizebronco forum was, that maybe the PIP-Sensor is defective.

It was planed to get the car running until friday to drive in holidays...but I don't have much hope anymore that I will be able to fix the problem in that time.

Thanks in advance for your help...I will post images and more information next year, when I'm back from holidays.

[Gary Lewis]

Rene - Welcome! Glad you joined.

I have lots of questions but know from our phone calls that you are desperate to get the truck running for a "hobby day" on Friday. I hope someone here has a magic bullet for you and will tag a few of them that might so they know you've posted.

For the others, he replaced the ECU today with one for a 351W since that's closer to what he has in an engine now. But it didn't really change anything from the 302 ECU - both of them have it running really rich.

[Gary Lewis]

Rene - Welcome! Glad you joined.

I have lots of questions but know from our phone calls that you are desperate to get the truck running for a "hobby day" on Friday. I hope someone here has a magic bullet for you and will tag a few of them that might so they know you've posted.

For the others, he replaced the ECU today with one for a 351W since that's closer to what he has in an engine now. But it didn't really change anything from the 302 ECU - both of them have it running really rich.

Was just talking with Brandon/Bruno2 and we discussed the fact that your injectors appear to be firing twice per revolution of the distributor. That doesn't seem right, but it might happen if there's a short between Bank 1 and Bank 2 wiring.

I'd pull the connectors off the injectors and check continuity between the banks. In other words, between T/R and T/O wires. But you may have to pull the connector off the ECU to get an accurate read.

[mat in tn]

Rene - Welcome! Glad you joined.

I have lots of questions but know from our phone calls that you are desperate to get the truck running for a "hobby day" on Friday. I hope someone here has a magic bullet for you and will tag a few of them that might so they know you've posted.

For the others, he replaced the ECU today with one for a 351W since that's closer to what he has in an engine now. But it didn't really change anything from the 302 ECU - both of them have it running really rich.

which injectors? if they are the oem then they are the orange coded 19lb/hr rating.

[ReneH]

which injectors? if they are the oem then they are the orange coded 19lb/hr rating.

As I have done a new wiring for the injectors and also replaced all injector connectors, I have also double checked all wiring there. I have also replaced the 4-pin connector that goes directly to the ECU. So for testing I have set two LED lamps instead of the injectors directly to pin 58 and 59. Pin 58 and 59 are not shorten and only going to GND, if the engine cranks and the ecu gives the signal.

I have bought original Bosch injectors, refurbished. They seem to work fine.

Both you can see here in some videos I have made:

[Gary Lewis]

As I have done a new wiring for the injectors and also replaced all injector connectors, I have also double checked all wiring there. I have also replaced the 4-pin connector that goes directly to the ECU. So for testing I have set two LED lamps instead of the injectors directly to pin 58 and 59. Pin 58 and 59 are not shorten and only going to GND, if the engine cranks and the ecu gives the signal.

I have bought original Bosch injectors, refurbished. They seem to work fine.

Both you can see here in some videos I have made:

Looks like you have the orange injectors. However, Bill/85lebaront2 said in another thread that "the injectors on the bank fired trucks are grouped 1 - end 4 (1458) 2 - center 4 (2367)". But in video #3 you show what appear to be 5, 6, 7, & 8 firing together, which doesn't fit with what Bill said.

Also, in the other videos where you have two LEDs in place of the injectors, it looks to me like both LEDs light at the same time, and do so two times per revolution of the distributor. They shouldn't light at the same time and shouldn't fire twice/distributor revolution.

Both of those things tell me that the wiring is wrong. Having all of the injectors fire at the same time, and twice per distributor revolution is wrong. And since you've replaced the ECU the only thing left that could do that is wiring.

It appears that there's a connection between Ckt 95 and Ckt 96 some place and that is causing all injectors to fire at the same time and twice per distributor revolution. I know you said you've checked, but I still think there's a connection between the two. I would pull the injectors and ECU off and check between 95 and 96 and ensure they aren't shorted to each other.

I've tagged Bill to see if he agrees with what I've said.

[mat in tn]

Looks like you have the orange injectors. However, Bill/85lebaront2 said in another thread that "the injectors on the bank fired trucks are grouped 1 - end 4 (1458) 2 - center 4 (2367)". But in video #3 you show what appear to be 5, 6, 7, & 8 firing together, which doesn't fit with what Bill said.

Also, in the other videos where you have two LEDs in place of the injectors, it looks to me like both LEDs light at the same time, and do so two times per revolution of the distributor. They shouldn't light at the same time and shouldn't fire twice/distributor revolution.

Both of those things tell me that the wiring is wrong. Having all of the injectors fire at the same time, and twice per distributor revolution is wrong. And since you've replaced the ECU the only thing left that could do that is wiring.

It appears that there's a connection between Ckt 95 and Ckt 96 some place and that is causing all injectors to fire at the same time and twice per distributor revolution. I know you said you've checked, but I still think there's a connection between the two. I would pull the injectors and ECU off and check between 95 and 96 and ensure they aren't shorted to each other.

I've tagged Bill to see if he agrees with what I've said.

that would certainly cause an extremely rich environment. in a batch fire system the injectors fire twice per cyl as it is and causing it to fire four times is terribly rich.it would also be enough so to cause the fuel pressure to stutter as it would be dumping fuel in much larger pulses. that should be seen on a gauge.

[ReneH]

Looks like you have the orange injectors. However, Bill/85lebaront2 said in another thread that "the injectors on the bank fired trucks are grouped 1 - end 4 (1458) 2 - center 4 (2367)". But in video #3 you show what appear to be 5, 6, 7, & 8 firing together, which doesn't fit with what Bill said.

Also, in the other videos where you have two LEDs in place of the injectors, it looks to me like both LEDs light at the same time, and do so two times per revolution of the distributor. They shouldn't light at the same time and shouldn't fire twice/distributor revolution.

Both of those things tell me that the wiring is wrong. Having all of the injectors fire at the same time, and twice per distributor revolution is wrong. And since you've replaced the ECU the only thing left that could do that is wiring.

It appears that there's a connection between Ckt 95 and Ckt 96 some place and that is causing all injectors to fire at the same time and twice per distributor revolution. I know you said you've checked, but I still think there's a connection between the two. I would pull the injectors and ECU off and check between 95 and 96 and ensure they aren't shorted to each other.

I've tagged Bill to see if he agrees with what I've said.

Yes, like I've said. Original Bosch forvthe 302, refurbished.

I have connected the same groups as mentioned. Identical to the original wiring.

5,6,7,8 are the one you see. 1,2,3,4 are still inside the mainfold, cause plenum was mounted.

That's why I've connected the leds, to better see what's happening and don't have so much fuel in the air...

I've used an ohmmeter to check 95 to 96 and both to +12v And GND...no connection anywhere.

The two leds are directly connected to the ECU...only 20cm original wiring between.

You see...that's the reason I'm despairing...

What do you think about the PIP theory.

I'm still using my original distributor with the original Hal sensor...

[85lebaront2]

Looks like you have the orange injectors. However, Bill/85lebaront2 said in another thread that "the injectors on the bank fired trucks are grouped 1 - end 4 (1458) 2 - center 4 (2367)". But in video #3 you show what appear to be 5, 6, 7, & 8 firing together, which doesn't fit with what Bill said.

Also, in the other videos where you have two LEDs in place of the injectors, it looks to me like both LEDs light at the same time, and do so two times per revolution of the distributor. They shouldn't light at the same time and shouldn't fire twice/distributor revolution.

Both of those things tell me that the wiring is wrong. Having all of the injectors fire at the same time, and twice per distributor revolution is wrong. And since you've replaced the ECU the only thing left that could do that is wiring.

It appears that there's a connection between Ckt 95 and Ckt 96 some place and that is causing all injectors to fire at the same time and twice per distributor revolution. I know you said you've checked, but I still think there's a connection between the two. I would pull the injectors and ECU off and check between 95 and 96 and ensure they aren't shorted to each other.

I've tagged Bill to see if he agrees with what I've said.

From my experience with the 1985/86 EFI systems, the engine harness is a common problem. I have no idea what Ford used for insulation on these, but it is frequently crumbling and will short across and to ground. Unfortunately, in order to really inspect the injector harness it needs to be completely accessible, meaning the plenum (upper manifold) needs to be removed.

Once that is done, disconnect the injectors and using a meter, check that the red, tan/orange and tan/red are all showing open circuit between them. While the meter is connected, try flexing the plug end (C160 on the diagram) of the harness to see if the readings change. Hopefully this will find your problem.

My other questions, (a) are you still using the original distributor and it's ignition module? (b) if original, is it a Motorcraft or aftermarket unit. © have you verified the wiring from the distributor. The reasons for these, the distributor has a shutter and a Hall effect pickup, one of the shutter vanes is narrower than the other 7 and this is what tells the computer where #1 cylinder is triggering the bank 1 injector pulse, bank 2 should trigger on the third wide vane following the narrow one. This gives two separate injector pulses per distributor revolution or, one per crank revolution. If the ignition system is giving improper signals to the computer, it will not work correctly (old computer term - GIGO Garbage in = Garbage Out).

 

[ReneH]

From my experience with the 1985/86 EFI systems, the engine harness is a common problem. I have no idea what Ford used for insulation on these, but it is frequently crumbling and will short across and to ground. Unfortunately, in order to really inspect the injector harness it needs to be completely accessible, meaning the plenum (upper manifold) needs to be removed.

Once that is done, disconnect the injectors and using a meter, check that the red, tan/orange and tan/red are all showing open circuit between them. While the meter is connected, try flexing the plug end (C160 on the diagram) of the harness to see if the readings change. Hopefully this will find your problem.

My other questions, (a) are you still using the original distributor and it's ignition module? (b) if original, is it a Motorcraft or aftermarket unit. © have you verified the wiring from the distributor. The reasons for these, the distributor has a shutter and a Hall effect pickup, one of the shutter vanes is narrower than the other 7 and this is what tells the computer where #1 cylinder is triggering the bank 1 injector pulse, bank 2 should trigger on the third wide vane following the narrow one. This gives two separate injector pulses per distributor revolution or, one per crank revolution. If the ignition system is giving improper signals to the computer, it will not work correctly (old computer term - GIGO Garbage in = Garbage Out).

Ok. I have replaced all injector connectors and made a complete new wiring from the injectors and the o2 sensor to the 4 pin connector near the firewall on the driver's side.

I also have made the measurements you've described...nothing short...

Yes I use the original motorcraft distributor. Changing the ignition control module to a new one also had no effect.

The check that is left are the wires directly to the ECU...I still use the stock connector on the distributor. I also have checked the spark-plug cable. All have a spark.

So my question in this case is, if the ignition works (so far I can see) is it possible That only the signal for the injectors coming from the ignition control module is wrong?

Maybe also something with these shutter wheel...it is possible that a former owner has build in a wrong distributor...maybe I should buy one for the 1986 351W engine. I already have bought the ECU from this year, cause my setup is closer to 351W than to 302...