1985 4Runner only runs on cold start injector

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Hey y’all! I’m in need of someone smarter than I when it comes to early efi on the 22re. My 85 4Runner will only run on the cold start injector, then dies. New fuel pump, starter, efi relay, open circuit relay, and grounds cleaned or replaced. Any input on where to look?
Got it to pop code 10 once when I hit the throttle then it died. Not sure if that helps.
 
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The only thing that can make this actually happen are, bad injectors or injector wiring, a bad COR or bad AFM.

I strongly recommend diagnosis before throwing a bunch of money at parts.
 

pappy

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Inside the wire harness to the injectors are several splices. Those splices are known to corrode. It will require removal of the harness, and pealing back the tape to see them. I would start here before spending money. Also, on the 1985 trucks there is a resistor thingy on the passenger fender that the injectors run through. I've never seen one fail, but that is also in the circuit.
 
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The only thing that can make this actually happen are, bad injectors or injector wiring, a bad COR or bad AFM.

I strongly recommend diagnosis before throwing a bunch of money at parts.
What’s the best way to diagnose the afm?
 
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For where you're at, start with KOEO finger the flap and see if fuel pump kicks on.
Otherwise you need a DMM
 
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Inside the wire harness to the injectors are several splices. Those splices are known to corrode. It will require removal of the harness, and pealing back the tape to see them. I would start here before spending money. Also, on the 1985 trucks there is a resistor thingy on the passenger fender that the injectors run through. I've never seen one fail, but that is also in the circuit.
I was looking into the injector resistor and I did the ohm test that I had found, the person said resistance should be 2-3obms, my readings were all over the place much higher. Thoughts?
 
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Inside the wire harness to the injectors are several splices. Those splices are known to corrode. It will require removal of the harness, and pealing back the tape to see them. I would start here before spending money. Also, on the 1985 trucks there is a resistor thingy on the passenger fender that the injectors run through. I've never seen one fail, but that is also in the circuit.
Are there any tricks to accessing any of the injectors so I can put a mood light on it? Or do I got pop the upper intake off?
 

KLF

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Do not pas Go, do not collect $200... Do as @pappy says and go directly to the main engine harness and yank it out of the truck. Start peeling black tape and loom off the wires. Here is what you will likely find at the splices:

InjectorSplice.jpg

InjectorSplice2.jpg


That is what those infamous splices in the injector circuit looked like in the harness in my red '87 when I pulled it apart 8 years ago.

One end of the harness is connected to the ECU under the glovebox, you'll have to pull it through the firewall. The other end is snaked around the intake. It's easier to remove with the upper intake off, but not absolutely necessary.
 
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Do not pas Go, do not collect $200... Do as @pappy says and go directly to the main engine harness and yank it out of the truck. Start peeling black tape and loom off the wires. Here is what you will likely find at the splices:

View attachment 2264363
View attachment 2264364

That is what those infamous splices in the injector circuit looked like in the harness in my red '87 when I pulled it apart 8 years ago.

One end of the harness is connected to the ECU under the glovebox, you'll have to pull it through the firewall. The other end is snaked around the intake. It's easier to remove with the upper intake off, but not absolutely necessary.
I will definitely do that, however the injector resistor that @pappy mentioned is clearly toast after I had an engineer friend walk me through a couple tests. Resistance is extremely out of spec and no continuity present. Need to start there once I can find one...
 

KLF

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Like I said, start at the ECU behind the kickpanel on the passenger side. Big connector on the ECU, pop it off, then start snaking it out of the firewall. It's easier than it sounds.

You could tape-flag all the connectors as you pull them off the engine. Trying to remember all the connectors (it's been awhile).

One for each injector
Grounds on the intake
Temp sensors at the front
TPS
Gauge sender
Cold start injector
Oil pressure sender
Knock sensor
Diagnostic connector at the fusebox (you might not have this?)
Wire across the valve cover to the coil
Trans connector
AC compressor clutch

Here, should look like this when it's out:
DSC_0139.JPG


The big black grommet is where it goes through the firewall.
 
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Like I said, start at the ECU behind the kickpanel on the passenger side. Big connector on the ECU, pop it off, then start snaking it out of the firewall. It's easier than it sounds.

You could tape-flag all the connectors as you pull them off the engine. Trying to remember all the connectors (it's been awhile).

One for each injector
Grounds on the intake
Temp sensors at the front
TPS
Gauge sender
Cold start injector
Oil pressure sender
Knock sensor
Diagnostic connector at the fusebox (you might not have this?)
Wire across the valve cover to the coil
Trans connector
AC compressor clutch

Here, should look like this when it's out:
View attachment 2264433

The big black grommet is where it goes through the firewall.
Well I just retested the resistor and it gave me 3.5 ohms resistance. 12v roughly in and out. Is that spec? I thought 2-3 ohms resistance was spec so it seems close enough. Looks like harness it is.
 

KLF

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How far back are the splices? Can I fix them with the harness still mildly in place?
I seem to remember they are at the thickest part, near that bracket where the harness makes a 90deg bend. It might be possible to get to them while it's in the truck.
 
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I seem to remember they are at the thickest part, near that bracket where the harness makes a 90deg bend. It might be possible to get to them while it's in the truck.
Alright! I’m motivated for it to be my project starting first thing in the am! I know I’m getting power from the resistor. So I know to work from there upward!
 
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Alright! I’m motivated for it to be my project starting first thing in the am! I know I’m getting power from the resistor. So I know to work from there upward!
For some reason I just re-tested the resistor and it fell into spec, so that’s a major plus!
 
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