ReneH Posted December 9, 2023 Author Share Posted December 9, 2023 Seems like the ACT may be the problem. As for the lifter noise, Big Blue has one that taps when it is cold but goes away when warmed up. It is just a bit loose but isn’t causing a problem, so I’m not going to worry about it. So, I've changed the ACT without noticeable effect...if I disconnect it, the engine starts much better, like before. I'll check my wiring to the ECU, but as far as I remember, I've checked it twice before connecting the sensors... Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 9, 2023 Share Posted December 9, 2023 So, I've changed the ACT without noticeable effect...if I disconnect it, the engine starts much better, like before. I'll check my wiring to the ECU, but as far as I remember, I've checked it twice before connecting the sensors... I'm struggling to understand why it would start better w/o the ACT unless you have the wrong ACT sensor. Or if you have the ACT sensor connected to another input instead. Like maybe MAP? This is where the EEC-V shines as you can log all of the inputs and see how they are responding. I don't think you can do that with EEC-IV. Link to comment Share on other sites More sharing options...
ReneH Posted December 9, 2023 Author Share Posted December 9, 2023 I'm struggling to understand why it would start better w/o the ACT unless you have the wrong ACT sensor. Or if you have the ACT sensor connected to another input instead. Like maybe MAP? This is where the EEC-V shines as you can log all of the inputs and see how they are responding. I don't think you can do that with EEC-IV. Hi Gary, Maybe, you can tag Bill, in case of the pinout. I use a 1989 351W ECU. In my excel list o have set the ATC to Pin no. 25. Looking at the 1989 pinout, 25 is ign. Gnd...ACT is pin 29...I'm a bit confused... Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 9, 2023 Share Posted December 9, 2023 Hi Gary, Maybe, you can tag Bill, in case of the pinout. I use a 1989 351W ECU. In my excel list o have set the ATC to Pin no. 25. Looking at the 1989 pinout, 25 is ign. Gnd...ACT is pin 29...I'm a bit confused... You can tag Bill yourself. On the Assignment dropdown, below, just click the center one and assign it to 85lebaront2, like I've done. But I'll bet he's going to point you to the documentation he provided on our page at Documentation/Electrical/ELECTRONIC ENGINE CONTROL (EEC). There click the Pin Outs tab and then go to the bottom of the page and pick the EFI 5.8 tab. And on there I see 25 being ignition ground and 29 being ACT. Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 10, 2023 Share Posted December 10, 2023 Hi Gary, Maybe, you can tag Bill, in case of the pinout. I use a 1989 351W ECU. In my excel list o have set the ATC to Pin no. 25. Looking at the 1989 pinout, 25 is ign. Gnd...ACT is pin 29...I'm a bit confused... Rene' the 1985/86 truck EFI pinouts are different from the 1987 up ones. Link to comment Share on other sites More sharing options...
ReneH Posted December 10, 2023 Author Share Posted December 10, 2023 You can tag Bill yourself. On the Assignment dropdown, below, just click the center one and assign it to 85lebaront2, like I've done. But I'll bet he's going to point you to the documentation he provided on our page at Documentation/Electrical/ELECTRONIC ENGINE CONTROL (EEC). There click the Pin Outs tab and then go to the bottom of the page and pick the EFI 5.8 tab. And on there I see 25 being ignition ground and 29 being ACT. So, I currently check the excel list...everything seems to fit... On the 1989, 5.8l tab, there is pin25 described with circuit 310, that means 310 is ACT... Pin 29 is circuit 94: HEGO. So, my pinout seems to be correct... But this means, the problem caused elsewhere... Some other ideas? Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 10, 2023 Share Posted December 10, 2023 So, I currently check the excel list...everything seems to fit... On the 1989, 5.8l tab, there is pin25 described with circuit 310, that means 310 is ACT... Pin 29 is circuit 94: HEGO. So, my pinout seems to be correct... But this means, the problem caused elsewhere... Some other ideas? Rene - I see what you are saying. Where the 1989 column intersects with the Pin 25 row it says that's Ckt 310. And if you go over to the Circuit # column 310 is the ACT circuit. Bill - Are we reading it correctly? Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 10, 2023 Share Posted December 10, 2023 Rene - I see what you are saying. Where the 1989 column intersects with the Pin 25 row it says that's Ckt 310. And if you go over to the Circuit # column 310 is the ACT circuit. Bill - Are we reading it correctly? Yes, but look one column over, 1990 it becomes circuit 743, ACT or Air Charge Temperature still the same function. If you look at the resistance charts I sent you the ECT and ACT are the same values for a given temperature. Link to comment Share on other sites More sharing options...
Gary Lewis Posted December 10, 2023 Share Posted December 10, 2023 Yes, but look one column over, 1990 it becomes circuit 743, ACT or Air Charge Temperature still the same function. If you look at the resistance charts I sent you the ECT and ACT are the same values for a given temperature. So we are reading it correctly. And I see that ACT and ECT are the same resistance for the same temp, but does that mean Rene needs to do something? Are you suggesting that he ensure that he didn't interchange them in the wiring? Or, why did you mention it? Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 10, 2023 Share Posted December 10, 2023 So we are reading it correctly. And I see that ACT and ECT are the same resistance for the same temp, but does that mean Rene needs to do something? Are you suggesting that he ensure that he didn't interchange them in the wiring? Or, why did you mention it? With the engine cold, both should read the same resistance value within the tolerance. That is a sanity check. After running it and shutting it off, once everything has heat soaked for a bit they should again read the same within the tolerance. Link to comment Share on other sites More sharing options...
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