I have found someone who is selling several GM shop manuals to 3rd gen cars. He has:
87 Camaro electrical diagnosis supplement
88 Camaro elec. diagnosis supplement
88 Camaro service manual
89 Firebird service manual
90 Camaro service manual
92 Camaro service manual
Now for my questions. According to the Helm web site the 89 Firebird manual should also have a shop manual supplement. It does not say it is specifically an electrical supplement like the Camaro manuals. Does anyone know if the wiring diagrams are in the main service manual or the supplement for this one? My next question; is there really any difference in the wiring between the 87, 88 & 89 cars? I am really only interested in the engine controls and ECM & wiring harness. Could I get the 88 Camaro manual and electrical supplement and be set for all the 86-89 MAF systems? How about with the 90 & 92 manuals. Do I really need both of them or would one do to cover the Speed Density models? My interest in these is to use as a guide in doing engine conversions into older vehicles. So all I am really interested in the electrical diagnosis & wiring harness etc.

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