86 Riviera ECM

okspit

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Help! I have an 86 Riviera with only 40k in very nice shape but it wont run. I believe that the ECM is bad. Where can I locate one as a replacement?
 
What made you come to the conclusion it's a bad ecm and not a ignition module, crank or cam sensor or simple ign/injector fuse?
 
What made you come to the conclusion it's a bad ecm and not a ignition module, crank or cam sensor or simple ign/injector fuse?
I have replaced the crank sensor, the ignition coils and the ignition module. When I plug in the obd sensor I have about 7 seconds to read it before it goes blank. It hos said that the mass airflow sensor is at fault so that was replaced with a new on and the car wont start. Put the old one on and it starts but runs badly and quits. That makes me think that the ecm is bad and sending out erratic information.
 
I assume your using a obd1 scantool? try and get the power source directly from the battery with alligator clip attachment. Sometimes the lighter plug has contact issues.
I'm just relaying the information from my mechanic. I'm not sure what scanner he is using but I trust his judgement and skills. I will ask about the cam sensor as a possibility. What is the ing/injector fuse and where is it?
 
1984 - 1987 3.8 V6s have a significant problem with the camshaft timing gear breaking.

3.8 LG3.webp
 
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Thank You, I'll check the numbers to make sure that it is the correct part.
I had the ecm replaced but that wasn't it. The car starts well and idles well but is undrivable due to coughing and sputtering at random times and speeds. I'm now thinking a weak fuel pump. Pressure at the fuel rail is 22-24 lbs. It calls for 35-40 lbs. Could these be the symptoms of a weak fuel pump that is going bad? It is the original pump.
 
That is very low pressure but you need a better mechanic you have someone just throwing random parts at it and costing you money with his incompetent diagnostic ability. Several things can cause low fuel pressure, not just the pump. Filter, regulator come to mind. Voltage/current to the pump is another. You can bankrupt yourself replacing unnecessary parts so be careful
 
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