yes I searched

just wondering if there is a decent wiring diagram out there? Didn’t really see a legible one on here. The Haynes manual is worthless. Only has the 3rd gen diagram.

i did a mpfi swap on my 1991 std, and I have no power to my injectors. There’s power at a13 and a15, which are supposed to power the injectors. There’s power at the main relay. The main relay clicks twice.

I would REALLY just like to look at a decent diagram before I get much more confused.

i took the two yellow and black wires and bundled them together, and soldered them into the power wire that runs into the resistor box. There’s no power to either of those yellow and black wires that used to power the DPFI injectors in the old setup. I’m running a pm6 Ecu. Both mpfi swap tutorials I used said to do just what I described.

So... without a diagram I can’t really tell what’s happening between the ecu a13 and 15, the relay, the big passenger side connector which goes to those two injector power wires. I’d rather not just run a wire straight to the ecu from the resistor box, seems kinda ghetto.

what do y’all think?

Ok-

so- if I jump terminals 5 and 7 coming out of the main relay I get power to the injectors. I’ve tried 3 main relays, no luck. I’ve tried the fuses, they’re all good.

If I’m getting power to the injectors when I bypass the relay, it’s not the engine harness that I just modified. It’s something between the ecu and the relay.

is there a good wiring diagram for the Ef out there?

The only one one I can find is on a sketchy website called fundonkey.com that wants my credit card number.

I dont really expect anyone anyone to care about my wiring issues, but maybe someone could help with a source to a diagram

Got a clue-

hooked up a test light to power at the injector clip. It won’t turn on like it should- while cranking it or with key on engine off. Like i said.

The light will come on at an injector clip when the wires are jumped at the relay. Voltmeter is then at around 12v.

HOWEVER

***I noticed that the test light will come on while the pump is priming and then turn back off.****

the injectors are only getting power when the pump is on. Or at least only when priming when the key is initially turned on. Then they turn back off.

keep in mind: I ONLY changed the engine bay harness: and switched the pins at the ecu EXACTLY as layed out in various tutorials on this forum and on YouTube. I’ve triple checked everything. I’ve removed the engine harness and unwrapped it and checked everything. The engine harness is fine. Honestly it’s a straightforward swap.

does it sound like it could be the used pm6 ecu I bought? Or is there something else I’m not seeing.
also the ecu is flashing a code 20, (20 short blinks) ELD code.

Ive double checked all grounds.

Thanks!

Seth

Thanks everybody! Worked on it again today

The car will start if you spray brake clean down the tb.

As stated- no power from main relay to driver side connector/injectors. Tried a few relays.

they do have power if I use a jumper wire at the relay connector. This is stupefying because the car ran before- therefore if there was supposed to be power here then there WAS before the swap~~~ BUT I NEVER touched this part of the harness. I’m going to check the ignition switch tomorrow.

even when jumped and the injectors hot, the engine won’t start still! But will start with starter fluid still.

there is ground continuity between the ecu ground pins and the chassis.

There is voltage between the injector signal wires and ground. (A1 a3, a5, a7) should there be? I thought these were the pins through which the ecu grounded the injectors.

I no longer have any codes at the ecu.

i have fuel in my fuel lines.

Something else I find confusing- according to the wiring diagram- the injectors clearly share their power source with the fuel pump. So it makes sense that my injectors only get power when the pump is priming, and then they would theoretically be hot along with the pump when the engine is cranking or actually running. Yet everyone is stating that the injectors should have power anytime the ignition is on. This is strange.

Tomorrow im going to take the fuel rail off and see what’s going on with the injectors. I may try and get a noid light. I may go to a junkyard and just get a bunch of parts to load my shotgun instead of using proper diagnosis.

so to recap- I have spark. For some reason I don’t have 12v to my injectors. I can get 12v to my injectors but the car won’t start still. I have ground. I have continuity between all injector wires.

what is going on here

Thanks for everybody’s responses. I’ve determined that the injectors aren’t open all the time. With and without the relay jumped, I can get each injector to open by grounding it for a second. I made a noid light out of a test light. The injectors aren’t getting a signal to open from the ecu. Like I said, I can get each one to open manually. So what are some reasons for the ecu to not send those signals?

I double checked my distributor pinout- it’s correct. And I have a new distributor for a d16a6.

i have continuity between the injector pins at the ecu and the injectors. They’re all in the right order.

And yes, the dx gets its injector power from the pump, like I thought. But both get their power through the main relay. I’ve never heard of anyone having to repin or depin a main relay for a mpfi swap so.. I’m still mystified about that one.

and I was confused about the pins a1-a7 having power, they have current AVAILABLE but it’s not grounded.

this write up is pretty cool, man. I like that it’s all color coded.

so I just rechecked every pin at the ecu that’s supposed to be ground and they all check out.

Im going to go out on a limb here and assume it’s either the used ecu or the eBay dizzy I bought.

Wish me luck, I’ll report back.

Just waiting for a distributor to show up in the mail. Found another ecu and swapped it out, still no go.

Hypothetically- if the cyp or ckp were bad in the distributor, wouldn’t I get a code 4 or code 9? Or is it possible that someone just installed something wrong at a factory but the wiring is complete as to not throw a code?

Does anyone have any experience on this?

If anyone needs a pm6 let me know lol