thook

When you turn the key to ignition, a red rectanguler light on the dash instrument panel that says "engine" should come on. It let's you know that the ECU and EFI system is getting voltage.

poody81

i dont have a red engine light but i do have a orange check engine light that does not come on when it is acting up but when it does work that light does come on with the key in the on position. i went out to try to start it and it would not start but i left the key in the on position for about a half hour and it started right up

poody81

if the light is not comming on does that mean my computer is acting up or is it not getting power to the computer where do i go from here

abecedarian

In that drawing, the ignition switch supplies voltage to the contact portion of the COR, to one of the magnetic coils in the relay, and to a noise filter (the resistor / capacitor) across that coil. The other coil in the COR is supplied voltage by the ECU STA wire and grounds elsewhere. In function- the ECU powers one of the coils during cranking; the other coil is only activated whent the airflow through the AFM is sufficient to close the contacts in the AFM and ground the coil. The noise filter basically prevents any electrical noise from the AFM bouncing open and closed while cranking from inducing interference elsewhere in the wiring and causing problems such as momentarily turning the COR off and interfering with the ECU.
Essentially, trying to start the vehicle or having the engine running (and drawing air through the AFM) should both turn the COR on and activate the fuel pump.
I'm going to check the drawings for an 87 and see if they do in fact match this drawing to a tee. However, functionally, the systems work the same- COR is turned on by cranking and/or by airflow through the AFM.

poody81

i tired jumping the fuel pump from diagnosis port but i couldnt get the fuel pump to turn on

abecedarian

you did that with the key on?

poody81

yes i did

abecedarian

have you tried jumping directly from the battery + terminal to the FP terminal in the box?

poody81

havent tried that yet ill have to give that a try in the morning

thook

Wait a minute.....the FP and B+ terminals in the box, as Abe describes, is in the diagnostic port as you describe that you've already tried but could not get the fuel pump to work that way. Hmmm.....conundrum.

abecedarian

B+ should only be hot with the key on, which he didn't try.

thook

Wait another minute....I got confused. Derf!!

You were saying "directly from the battery terminal". I thought you meant the B+ terminal in the diagnostic box.

Oh, and he did say he tried with the key on at the diagnostic port. He just didn't try directly from the battery to FP port/diagnostic box....which wouldn't require the key.

...sorry. <<<ignore me>>>

abecedarian

Yeah, then I derf'd... he tried it B+>FP with key on... didn't try straight from batt...
/me slaps self

thook

/me slaps abe...then slaps self.

/sin slaps us both.

/both drink some Irish cream and go to bed.

/'nighty night......zzzzzzzzzzzzzzz