ECU Substitution?, Using 1974 ECU in a 1973 |
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ECU Substitution?, Using 1974 ECU in a 1973 |
ThinAir |
Jul 16 2020, 10:44 PM
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#1
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Best friends Group: Members Posts: 2,543 Joined: 4-February 03 From: Flagstaff, AZ Member No.: 231 Region Association: Southwest Region |
My stock 1973 2.0L has developed a problem. Intermittently, the engine will start stumbling and then die. Sometimes reseating the 14 pin connector/harness on the relay board will get things going. Other times I have to just let it sit for awhile. I've noticed recently that when this happens it also smells like it is flooded and when starting it I have to floor the accelerator.
A long time ago I had a similar problem with my son's 1970 that ultimately was resolved by replacing the ECU. Hence the following question: I have available a working 1974 ECU. I'm wondering if I can swap ECUs with no other modifications to see if the problem goes away and stays away. Brad Anders' FI page states that the 1973 should use only a particular ECU, but in his chart of the preferred setup he states to use the 1974 ECU. Would it be harmful to any component to swap the ECUs and test my theory? This problem came up just before leaving for a summer road trip and I won't be able to work on it until just before Labor Day, but I'm hoping to figure out a direction now so that I can jump on it when I get back home and get the car ready for the RRC. |
JamesM |
Jul 17 2020, 08:42 AM
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#2
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Senior Member Group: Members Posts: 1,922 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
I've noticed recently that when this happens it also smells like it is flooded and when starting it I have to floor the accelerator. That sounds like it could be your MPS or your head temp sensor/connection to your head temp sensor. Either of those failing can cause behavior like that. Open circuit on the head temp sensor causes an extremely rich condition as does an MPS that wont hold vacuum and either one of these can vary/be affected by heat and or motion. If moving the harness around sometimes resolved the issue though I would be very suspect of the wire/connection to the head temp sensor. |
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