ReneH Posted March 4, 2023 Share Posted March 4, 2023 Hi together. After doing these and those...all new parts and complete new engine control harness...the problem stays the same. All 8 injectors firing twice per revolution... I don't know where to search for the failure anymore. It's It's bewitched. I have some strange values, in my opinion, between ingintion run, ignition Start and battery plus...both are low ohmic...I don't know if this is common... I have a 302/347 stroker with a 351W cam and 351W ECU... Can the cam be the problem? Or maybe in combination with my distributor? I'm currently not sure, if the distributor is from a 351W or a 302...it's also a new part, including the TFI module. Maybe it's a problem of the missing emissions control. I have removed everything...but I have had the same problems only without the EGR vent...so I don't believe that this is a part of the problem... Maybe my test is wrong, cause I have connected the leds directly to the ECU outputs (58, 59) and ignition run. Same procedure when connecting to battery plus instead of ignition run... Link to comment Share on other sites More sharing options...
ReneH Posted March 4, 2023 Author Share Posted March 4, 2023 Hmmm...can it be "normal" that all 8 injectors firing together while the engine is cranking? Only for starting purposes? I'm helpless...sorry for that wired theory... Link to comment Share on other sites More sharing options...
85lebaront2 Posted March 5, 2023 Share Posted March 5, 2023 Hmmm...can it be "normal" that all 8 injectors firing together while the engine is cranking? Only for starting purposes? I'm helpless...sorry for that wired theory... It may be a crank mode for cold starts. I do notice that it appears to fire at #1 and #6 rotor positions both banks at the same time. A couple of tests, first, unplug the crank signal wire from the starter relay and use a push button jumper switch to repeat the test with the key on and see if both injector banks still fire together every crank revolution. If they do not, then the double pulse is a start item, if they still do then there is definitely something strange going on. Second, regardless of the first test results, unplug the coolant temperature sensor (light green with yellow wire and black with white wire, in coolant passage front of intake) and put a 3000 ohm resistor across the connectors in the plug. This will cheat the computer into thinking the engine is warm. Then repeat the first test, if the system now alternately triggers the banks, see if you can get it to start and run (maybe poorly) like this. At that point I would check the coolant temperature sensor resistance from the chart I sent. Link to comment Share on other sites More sharing options...
ReneH Posted March 5, 2023 Author Share Posted March 5, 2023 It may be a crank mode for cold starts. I do notice that it appears to fire at #1 and #6 rotor positions both banks at the same time. A couple of tests, first, unplug the crank signal wire from the starter relay and use a push button jumper switch to repeat the test with the key on and see if both injector banks still fire together every crank revolution. If they do not, then the double pulse is a start item, if they still do then there is definitely something strange going on. Second, regardless of the first test results, unplug the coolant temperature sensor (light green with yellow wire and black with white wire, in coolant passage front of intake) and put a 3000 ohm resistor across the connectors in the plug. This will cheat the computer into thinking the engine is warm. Then repeat the first test, if the system now alternately triggers the banks, see if you can get it to start and run (maybe poorly) like this. At that point I would check the coolant temperature sensor resistance from the chart I sent. Hi Bill, Thanks, I will perform these things. But I don't understand what I should connect with a switch together... "and use a push button jumper switch to repeat the test with the key on" EDIT OK...sometime it takes a while for understanding...I've got it: 1. remove Starter relay signal cable from the regarding post at the relay 2. Connect a switch between battery plus and starter relay signal post 3. Turn ignition switch to "run" 4. switch the signal to the starter relay to simulate the engine is running... How does the ECU is knowing that the engine is running? If I disconnect the signal from ignition Start from the starter relay, the starter motor won't turn and also the distributor will stand still and give no signals to the ECU, or am I wrong? In the beginning, as I have run the engine, I have done a cam break-in. Although not knowing the problem at this time, the engine was at temperature and runs rich as hell...assumed that my problem was not the old engine harness, the problem is still the same... another theory Does the injectors have a "real" plus and minus? As far as I know they are only inductors, so it's not possible to wire them wrong...assumed they can be miss wired, maybe it is possible that the bank, with e.g. one miss wired injector, gets its current flowing over this injector while the ECU triggers the other bank... Ok...while writing this, It comes in my mind that I haven't currently connected this whole circuit...the LEDs are directly connected to the ECU pins...so the reason must be somewhere else...sorry for the wrong-way-theory... Link to comment Share on other sites More sharing options...
ReneH Posted March 5, 2023 Author Share Posted March 5, 2023 Hi Bill, Thanks, I will perform these things. But I don't understand what I should connect with a switch together... "and use a push button jumper switch to repeat the test with the key on" EDIT OK...sometime it takes a while for understanding...I've got it: 1. remove Starter relay signal cable from the regarding post at the relay 2. Connect a switch between battery plus and starter relay signal post 3. Turn ignition switch to "run" 4. switch the signal to the starter relay to simulate the engine is running... How does the ECU is knowing that the engine is running? If I disconnect the signal from ignition Start from the starter relay, the starter motor won't turn and also the distributor will stand still and give no signals to the ECU, or am I wrong? In the beginning, as I have run the engine, I have done a cam break-in. Although not knowing the problem at this time, the engine was at temperature and runs rich as hell...assumed that my problem was not the old engine harness, the problem is still the same... another theory Does the injectors have a "real" plus and minus? As far as I know they are only inductors, so it's not possible to wire them wrong...assumed they can be miss wired, maybe it is possible that the bank, with e.g. one miss wired injector, gets its current flowing over this injector while the ECU triggers the other bank... Ok...while writing this, It comes in my mind that I haven't currently connected this whole circuit...the LEDs are directly connected to the ECU pins...so the reason must be somewhere else...sorry for the wrong-way-theory... Hi Bill, everything stays the same. Although with 3k ohms for the water temperature and external starter signal...I don't understand this holy sh**. Isn't it possible that the 351W cam is the problem? It has another ignition order than the 302 cam. I use the original 302 distributor... I use this cam: SummitRacing And this distributor: RockAuto In my understanding the ECU gets the pulse for firing the injectors from the TFI module. So as there can be nothing wrong on the output side of the ECU (Pin 58 and 59), cause there are only LEDs directly connected to them, the error can only be caused by the information the ECU gets as input. So that's my theory...now I stuck by analyzing, cause I don't know where to start... Maybe there is a failure in the Analysis, cause although if I do the cranking with external voltage I have read that the ECU knows the rpm of the engine...so maybe it also knows that the engine is not running:nabble_anim_confused: So I will connect also the injectors together with the leds and see what's happening, when the engine runs... But I hope someone has a better idea before... Link to comment Share on other sites More sharing options...
85lebaront2 Posted March 5, 2023 Share Posted March 5, 2023 Hi Bill, Thanks, I will perform these things. But I don't understand what I should connect with a switch together... "and use a push button jumper switch to repeat the test with the key on" EDIT OK...sometime it takes a while for understanding...I've got it: 1. remove Starter relay signal cable from the regarding post at the relay 2. Connect a switch between battery plus and starter relay signal post 3. Turn ignition switch to "run" 4. switch the signal to the starter relay to simulate the engine is running... How does the ECU is knowing that the engine is running? If I disconnect the signal from ignition Start from the starter relay, the starter motor won't turn and also the distributor will stand still and give no signals to the ECU, or am I wrong? In the beginning, as I have run the engine, I have done a cam break-in. Although not knowing the problem at this time, the engine was at temperature and runs rich as hell...assumed that my problem was not the old engine harness, the problem is still the same... another theory Does the injectors have a "real" plus and minus? As far as I know they are only inductors, so it's not possible to wire them wrong...assumed they can be miss wired, maybe it is possible that the bank, with e.g. one miss wired injector, gets its current flowing over this injector while the ECU triggers the other bank... Ok...while writing this, It comes in my mind that I haven't currently connected this whole circuit...the LEDs are directly connected to the ECU pins...so the reason must be somewhere else...sorry for the wrong-way-theory... Rene', when you crank the engine using the key, there is a start signal sent to pin# 30 of the computer and also to the TFI module (which should be a gray one if it is a Motorcraft one). There are 4 TFI modules, two are distributor mounted and two are remote mounted (driver's side inner fender). They are similar except for one item, the gray ones use a starter trigger to increase the dwell time when starting, the black ones are called CCD for Computer Controlled Dwell. A few posts back you were checking wiring and raised a question regarding the white/light blue wire. This is fed from two different sources in the ignition switch. The reason for this is Ford used one front harness for all gas engine trucks in 1985/86. The Duraspark (non EEC engines) required a resistor in the coil feed which is the red/light green wire, the white/light blue is connected in the harness to the red/light green with a resistance wire. When starting, the red/light green wire is fed 12V through the ignition switch, once the truck is running, it reverts to the resistance. On the EFI trucks the red/light green and white/light blue are connected together, but, the red/light green becomes brown with pink. The reason I wanted you to disconnect the starter signal wire from the relay and use a push button switch to activate it (battery+ to the start signal pin) is to take the wiring used for ignition feed in starting out of the system to simulate the engine started and running. As an FYI, basically all EFI systems trace their design back to a Bendix system used unsuccessfully by Chrysler in 1958, they sold the design to Bosch who fixed the problems. Many of the older Bosch systems used a cold start injector that was not controlled by the computer. Later ones simply increase the time and possibly the pulse frequency. When I was checking and setting up the system on my 1986 Chrysler convertible, I discovered that when starting the engine cold, all 4 injectors pulse together, but once running go back to a sequential system (1342). This is how the cold start works. That is why I want to see if simulating a running engine will change the pulse sequence of the injectors. Link to comment Share on other sites More sharing options...
ReneH Posted March 5, 2023 Author Share Posted March 5, 2023 Rene', when you crank the engine using the key, there is a start signal sent to pin# 30 of the computer and also to the TFI module (which should be a gray one if it is a Motorcraft one). There are 4 TFI modules, two are distributor mounted and two are remote mounted (driver's side inner fender). They are similar except for one item, the gray ones use a starter trigger to increase the dwell time when starting, the black ones are called CCD for Computer Controlled Dwell. A few posts back you were checking wiring and raised a question regarding the white/light blue wire. This is fed from two different sources in the ignition switch. The reason for this is Ford used one front harness for all gas engine trucks in 1985/86. The Duraspark (non EEC engines) required a resistor in the coil feed which is the red/light green wire, the white/light blue is connected in the harness to the red/light green with a resistance wire. When starting, the red/light green wire is fed 12V through the ignition switch, once the truck is running, it reverts to the resistance. On the EFI trucks the red/light green and white/light blue are connected together, but, the red/light green becomes brown with pink. The reason I wanted you to disconnect the starter signal wire from the relay and use a push button switch to activate it (battery+ to the start signal pin) is to take the wiring used for ignition feed in starting out of the system to simulate the engine started and running. As an FYI, basically all EFI systems trace their design back to a Bendix system used unsuccessfully by Chrysler in 1958, they sold the design to Bosch who fixed the problems. Many of the older Bosch systems used a cold start injector that was not controlled by the computer. Later ones simply increase the time and possibly the pulse frequency. When I was checking and setting up the system on my 1986 Chrysler convertible, I discovered that when starting the engine cold, all 4 injectors pulse together, but once running go back to a sequential system (1342). This is how the cold start works. That is why I want to see if simulating a running engine will change the pulse sequence of the injectors. Hi Bill, thanks for this Information. I'm don't stop learning while writing with you. I have found a book (PDF) named Ford Fuel Injection & Electronic Engine Control from Charles O. Probst. Very interesting things inside. 440 pages that also tell how the EFI-System works inside...but also there I have't found a solution. By the way, do you know this book? OK, back to the Problem: First about what I use: - 1989 351W ECU - Distributor from Cardone (Same article number for 1986 302 and 1989 351W) I still have my original distributor from Motorcraft with Motorcraft TFI. I wanted to replace the HAL Sensor inside and save the refirbished distributor as spare-part. Only to be sure: If I use a 1989 ECU from the 351W I have bank-fired injectors for sure! OK, I still need something to continue. I'm out of ideas where to search now. The following possibilities are still in my mind as reason for the behavior: - Problem with my cam from the 351W - Something wrong with the Ignition-switch or the regarding circuit So, that's it - End of ideas. The problem with the cam is something I only hope I'm as wrong as I can be... I still can't imagine what's the reason for letting the ECU fire both channels simultaneously. As I have nothing between the output for both channels, I only can imagine that the ECU gets wrong information. So as I also can't imagine what information this could be instead of a wrong signal from the TFI. So also FIY: I have seen that the injectors get one short (about 1 sec.) pulse when turning the key. Short time after the fuel pump has build up pressure. Also all 8 simultaneously. But I think this may be normal to have some extra fuel for starting...so that's my explanation. So how could I continue? The truck stands now over a year since bought...I only planed to change some simple things...now look what I've got... Same thing with my CJ7...bought it, runs about 4 month...then new engine and everything new...this seems to be a curse... Link to comment Share on other sites More sharing options...
85lebaront2 Posted March 5, 2023 Share Posted March 5, 2023 Hi Bill, thanks for this Information. I'm don't stop learning while writing with you. I have found a book (PDF) named Ford Fuel Injection & Electronic Engine Control from Charles O. Probst. Very interesting things inside. 440 pages that also tell how the EFI-System works inside...but also there I have't found a solution. By the way, do you know this book? OK, back to the Problem: First about what I use: - 1989 351W ECU - Distributor from Cardone (Same article number for 1986 302 and 1989 351W) I still have my original distributor from Motorcraft with Motorcraft TFI. I wanted to replace the HAL Sensor inside and save the refirbished distributor as spare-part. Only to be sure: If I use a 1989 ECU from the 351W I have bank-fired injectors for sure! OK, I still need something to continue. I'm out of ideas where to search now. The following possibilities are still in my mind as reason for the behavior: - Problem with my cam from the 351W - Something wrong with the Ignition-switch or the regarding circuit So, that's it - End of ideas. The problem with the cam is something I only hope I'm as wrong as I can be... I still can't imagine what's the reason for letting the ECU fire both channels simultaneously. As I have nothing between the output for both channels, I only can imagine that the ECU gets wrong information. So as I also can't imagine what information this could be instead of a wrong signal from the TFI. So also FIY: I have seen that the injectors get one short (about 1 sec.) pulse when turning the key. Short time after the fuel pump has build up pressure. Also all 8 simultaneously. But I think this may be normal to have some extra fuel for starting...so that's my explanation. So how could I continue? The truck stands now over a year since bought...I only planed to change some simple things...now look what I've got... Same thing with my CJ7...bought it, runs about 4 month...then new engine and everything new...this seems to be a curse... Rene' did the original distributor run? If so, plug the harness in to it, don't bother to install it. With the key on, spin the distributor shaft and see if you get the double pulse of your two test lights. If you do, I would suspect the computer. I do not recall my son's F150 or any other I have worked on firing the injectors at key on. When you do this, note if the fuel pump is running all the time the key is on, or just an initial cycle followed by running when the distributor is spun. Was the original computer bad or did you change to better accommodate the larger engine? Link to comment Share on other sites More sharing options...
ReneH Posted March 5, 2023 Author Share Posted March 5, 2023 Rene' did the original distributor run? If so, plug the harness in to it, don't bother to install it. With the key on, spin the distributor shaft and see if you get the double pulse of your two test lights. If you do, I would suspect the computer. I do not recall my son's F150 or any other I have worked on firing the injectors at key on. When you do this, note if the fuel pump is running all the time the key is on, or just an initial cycle followed by running when the distributor is spun. Was the original computer bad or did you change to better accommodate the larger engine? Hi Bill, Yes, the original distributor runs. Also the original ECU. As this failure coming up after reassembling the engine, I have changed every sensor and also the distributor and the ECU to find the error...all the same ending...both injector lines firing together... As I haven't connected the injectors, the pump can run as it likes...should have no effect, since the refurbished injectors close correct...what they do, cause I have checked this before. And yes, as I thought my 302 computer is maybe bad, I've bought the one for the 351W cause it fits better to my 347 stroker specs. I will try this with my old distributor, but I don't have much hope, cause I have had the same failure with it before...that's the reason to replace it... Link to comment Share on other sites More sharing options...
85lebaront2 Posted March 5, 2023 Share Posted March 5, 2023 Hi Bill, Yes, the original distributor runs. Also the original ECU. As this failure coming up after reassembling the engine, I have changed every sensor and also the distributor and the ECU to find the error...all the same ending...both injector lines firing together... As I haven't connected the injectors, the pump can run as it likes...should have no effect, since the refurbished injectors close correct...what they do, cause I have checked this before. And yes, as I thought my 302 computer is maybe bad, I've bought the one for the 351W cause it fits better to my 347 stroker specs. I will try this with my old distributor, but I don't have much hope, cause I have had the same failure with it before...that's the reason to replace it... Ok, don't forget there are several wiring changes from 1986 to 1987 and later. Link to comment Share on other sites More sharing options...
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