great question
the service manual on all cars made cover this act.
the RAD has 2 huge hoses. , one goes to the STAT
on most cars.
real engine name is L47 ,indy engine
it is here, part ID 12. from hose 16
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Why did you change the coils ??????? Do you know how to test electrical circuits with a DVOM - digital volt ohm meter ? Check for B+ voltage at the ignition module ,connector 2 pin C this is a pink wire . Check for a good ground at connector 2 pin A ,black with white stripe . Plus watch as many videos from this guy as you can on GM igntion systems .Your vehicle has two crankshaft position sensors .
GM Bypass Ignition System Operation part 1
check the battery...maybe the amp hours is not
sufficient...not original recommended battery....inconsistency in starting...the solenoid is a switch...which may need cleaning....the starter motor may be full of carbon dust....causes a short to earth and pulls battery power on startup....a big neglected area in car maintenance...
Blower motor control module probably , but without testing that's just a guess . Do you know how to do automotive electrical testing ? Testing B+ to the module ? Do you know where the module is ? You can find a wiring diagram here , http://www.bbbind.com/free_tsb.html There is a fuse for the blower motor in the I/P fuse box , HVAC blower 10amp ,
Please make sure to use , transmission oil cooler hose, And you don't need transmission out to change the hose you can even cut the line weres is leaking and splice it up, but if the hose you used blows up and hits the exhaust, it's probable it catch on fire, tyranny fluid is flammable at 300°f ,hose clams cut into the hose and fails ,you want to use a union..see pics
K
Sounds like you tripped the anti theft system ! Try removing the negative battery terminal for about 3 minutes , then reconnect ! That should work . If not Try you tube !
The firing order is:
1-2-7-3-4-5-6-8
From the left (front) bank of cylinders are number 2-4-6-8 and the right (rear) bank cylinders are 1-3-5-7. Engine firing order is 1-2-7-3-4-5-6-8.
Code 28 means there is a problem in the circuit for the transmission selector switch. The engine computer does not know what position the shifter is in.