ReneH Posted March 15, 2023 Author Share Posted March 15, 2023 with all emissions removed or disconnected it is very likely that the ecu is "taking roll call and no one is answering back" I am not sure which or if any are required at startup only but if the ecu registers egr as open it will read as a vacuum leak. it may be very necessary for you to fill in the blanks. when opting to delete any item I will usually have them all plugged into the harness and make alterations one at a time testing the results each time. your case may be a good teaching example of "only change one thing at a time" Hi Matt, yes, based on the knowledge I have got since over one year working on this engine, I'm with you at this point. I was also in the beginning, but others told me that the EEC won't do anything else with or without the whole emissions control hardware. So I've ignored it and searched for other reasons. After reading this very good book, I've sent scans above, I'm also convinced that it makes a difference...in particular if I consider how important are the emissions systems in the USA...it would be strange if the EEC won't care if it works or not... As I have done a complete new wiring harness, I don't have added cables that I don't need. So by having a new EEC connector with more than enough empty pins left over it will be no problem for me to add the resistors and check what's happening. I've got very deep inside how the EEC-IV is working, so let's call this whole thing a lesson learned and I hope that adding the resistors will solve the rich run and idle problem. But i still will check the TPS range tomorrow. Link to comment Share on other sites More sharing options...
mat in tn Posted March 15, 2023 Share Posted March 15, 2023 Hi Matt, yes, based on the knowledge I have got since over one year working on this engine, I'm with you at this point. I was also in the beginning, but others told me that the EEC won't do anything else with or without the whole emissions control hardware. So I've ignored it and searched for other reasons. After reading this very good book, I've sent scans above, I'm also convinced that it makes a difference...in particular if I consider how important are the emissions systems in the USA...it would be strange if the EEC won't care if it works or not... As I have done a complete new wiring harness, I don't have added cables that I don't need. So by having a new EEC connector with more than enough empty pins left over it will be no problem for me to add the resistors and check what's happening. I've got very deep inside how the EEC-IV is working, so let's call this whole thing a lesson learned and I hope that adding the resistors will solve the rich run and idle problem. But i still will check the TPS range tomorrow. this part is where it gets very interesting for me. if there is a means of communicating with the ecu that gives me more input then, I am interested. and I love watching along as others work. sometimes I see hazards and sometimes I see genius. I primarily use carburetors on things I build but I use efi a lot too. I just work with the ecu as completely as possible as I do not like a customer to say that my redesign did not work. especially if it cost them more money or inconvenience. I do experiment on my own trucks though. Link to comment Share on other sites More sharing options...
ReneH Posted March 15, 2023 Author Share Posted March 15, 2023 this part is where it gets very interesting for me. if there is a means of communicating with the ecu that gives me more input then, I am interested. and I love watching along as others work. sometimes I see hazards and sometimes I see genius. I primarily use carburetors on things I build but I use efi a lot too. I just work with the ecu as completely as possible as I do not like a customer to say that my redesign did not work. especially if it cost them more money or inconvenience. I do experiment on my own trucks though. Ok. I'll keep you up to date. The resistors will arrive tomorrow. I have measured that the other two EGR solenoids have another resistance. 40 ohms instead of 75 ohms, so I have also bought them. The TAB and TAD have both 75 ohms unencumbered (I hope this word is correct...) So, if it works, I'll build up a box for them near the ECU. I think there is much possible in manipulate the sensor data with basic electronics. As you know how it works, you can maybe build up a black-box to simulate, edit or fine-tune some data and as a result the behavior of the ECU, without manipulating the ECU itself. Link to comment Share on other sites More sharing options...
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