Idle trouble and loss of power 80s series (1 Viewer)

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
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Welp I'd order up some fresh toyota Knock sensors and replace them. Don't buy non-OEM knock sensors, I have before and they don't work at all (if you search around here you'll find my experience wasn't unique).

Falty knock sensors shouldn't prevent a start but they could.

Start there, but I think we need to check spark
 

SmokingRocks

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1975607


@Tjs23 you can also verify spark by fogging the intake filter box with starting fluid then cranking the engine for about 10 seconds. If it catches and fires for a second then spark is present. If you hold the starter two 10 second periods back to back and it doesn't kick over a little bit then spark is the issue.

Do you have your old plug wires, dizzy parts? if this test comes back as 'no spark' then swap all the new things you put on out with the old things and try again. Make sure you did plug in your dizzy cap.

IF those done work then we need to break out the multimeter and start checking resistance values / Ω ohms at the AFM, Dizzy, ECU (there is a known issue with the early 93 ecu's -I have a good running spare if you end up needing one-). We should have you replace your fusible links and efi main relay while there too.
 
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@SmokingRocks I followed the directions given. I eliminated the steps per the FSM. However, when checking the resistance of the ignition coil, I got a reading of 1.5 on the primary. The FSM states that it should be .36-.55 cold.

The secondary resistance checked within range at 12.55 cold. The FSM states that it should be 9.0-15.4 ohms.

Go ahead and pull the trigger on an ignition coil?
 

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
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yup. Get a new coil. (OEM or Denso/NGK)

How did it respond when you fogged the air filter with starter fluid?
 
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Updates:

1) NGK plugs and wires now installed
2) Denso cap and rotor installed

I am following the ON-Vehicle inspection Spark test per the FSM.

Since we have last spoken, The coil came in. I installed it and still no spark. Thinking I may return and purchase an igniter to see if that gets me going. I may have overlooked but I do not see any specifications on checking resistance to terminals with igniter. While the igniter is shipping I am going to dive in to the ECM and carefully check everything as explained starting on EG-231 of the service manual.

@SmokingRocks Am I headed in the right direction here?
 
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Updates:

1) NGK plugs and wires now installed
2) Denso cap and rotor installed

I am following the ON-Vehicle inspection Spark test per the FSM.

Since we have last spoken, The coil came in. I installed it and still no spark. Thinking I may return and purchase an igniter to see if that gets me going. I may have overlooked but I do not see any specifications on checking resistance to terminals with igniter. While the igniter is shipping I am going to dive in to the ECM and carefully check everything as explained starting on EG-231 of the service manual.

@SmokingRocks Am I headed in the right direction here?
I forgot to say that everything has checked out per the FSM until I reached the step telling me to check the ECM.
 

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
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part numbers are listed in this thread
 

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
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The engine needs: Compression, Fuel/Air mixture and Spark to run. We are assuming the compression is fine, know that fuel is present at the fuel rail and it sounds like we've narrowed in on a spark issue.

Based on what you've stated you have tested / confirmed the following on the spark branch:
  1. Checked, connections (removed, cleaned and reinstalled) at the Ignition Coil, Ignighter and Distributor
  2. Checked Resitanve of spark plug wires, all resistance was under 25k ohms
  3. Checked power supply to the ignition coil and ignigter. Verified that battery voltage is pressent at the + terminal on the coil
  4. Verified resistance of the ignition coil is within spec
  5. verified resitance of the signal generator is within specs
  6. Verified the gap in the distributor is within spec

Next check that the IGT signal from the ECU?

I think we need to verify that your distributor is sending the right signals to the ECU. Lets recap how spark is delivered so you can understand exactly why we need to check the distributors signals.

  1. Starter cranks over the engine which spins the distributor
    • A signal from the starter is delivered to the ECM to let it know that it's time to go. THis signal should be 6volts or more at the STA port at the computer. CHECK THIS, you will need to remove the glovebox to access the ECM. Measure voltage between STA and E1 port while cranking
    • 1989983

    • 1989982

    • If the voltage signal is confirmed then move to the next step
  2. The spinning distributor creates pulse signals that are sent to the ECM terminals, you will need to verify that these signals are present at the ECM. These signals allow the ECM to set the advance for the spark. Jump G1 to G-, G2 to G-, NE to G- while cranking, it helps to have a multi-meter that has a memory function.
    • 1989984
    • 1989985
 
Last edited:

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
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3. If the above signals are all verified at the ECM then check the signal from the ECU to the Igniter. Jump IGT to E1 and crank, then jump IGF to E1 and crank. If this passes the ECM is working. We will need to recheck the Igniter
4. Check all the ports on the Igniter
  • +B jumped to E1 should show battery voltage when key is in the on position
  • If we get to this point I suggest replacing the igniter and coil
 

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
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Did you end up replacing the coil? the road we are going down is starting to point in its direction, it would be good to replace that before you start probing at your ECM.
 
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Thank you @SmokingRocks! Once again, incredible info and help.

I replaced the ignition coil with an OEM Toyota part and I have an igniter and fusible link on the way. I’ve double checked all the fuses and relays. I haven’t probed around the ECM too much bc I know how fragile those things can be and there isn’t a whole lot of room to work with. I took a quick glance at the circuit board to see if there were any visible shorts and thankfully did not see any 🤞.

I certainly don’t want to get ahead of myself but I have found that there has been some previous rigging on this vehicle concerning the wiring. I believe someone may have tried to install an aftermarket door locking and starting system. I found a non-OEM box zip tied under my dash above the kick panel. I looked it up and found it to be from a manufacturer named “bulldog security systems” I believe particular box this is tied into my door locking system. This could be a possible lead if is has something to do with the ignition which I suspect it very well could have.

Patience and one step at the time will be the key to solving my problem. I will report back once igniter is installed.
 
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The engine needs: Compression, Fuel/Air mixture and Spark to run. We are assuming the compression is fine, know that fuel is present at the fuel rail and it sounds like we've narrowed in on a spark issue.

Based on what you've stated you have tested / confirmed the following on the spark branch:
  1. Checked, connections (removed, cleaned and reinstalled) at the Ignition Coil, Ignighter and Distributor
  2. Checked Resitanve of spark plug wires, all resistance was under 25k ohms
  3. Checked power supply to the ignition coil and ignigter. Verified that battery voltage is pressent at the + terminal on the coil
  4. Verified resistance of the ignition coil is within spec
  5. verified resitance of the signal generator is within specs
  6. Verified the gap in the distributor is within spec

Next check that the IGT signal from the ECU?

I think we need to verify that your distributor is sending the right signals to the ECU. Lets recap how spark is delivered so you can understand exactly why we need to check the distributors signals.

  1. Starter cranks over the engine which spins the distributor
    • A signal from the starter is delivered to the ECM to let it know that it's time to go. THis signal should be 6volts or more at the STA port at the computer. CHECK THIS, you will need to remove the glovebox to access the ECM. Measure voltage between STA and E1 port while cranking
    • View attachment 1989983
    • View attachment 1989982
    • If the voltage signal is confirmed then move to the next step
  2. The spinning distributor creates pulse signals that are sent to the ECM terminals, you will need to verify that these signals are present at the ECM. These signals allow the ECM to set the advance for the spark. Jump G1 to G-, G2 to G-, NE to G- while cranking, it helps to have a multi-meter that has a memory function.
 

SmokingRocks

I bought a Cruiser to keep miles off my Cruiser
Joined
Oct 6, 2014
Messages
3,432
Location
Colorado
I believe someone may have tried to install an aftermarket door locking and starting system. I found a non-OEM box zip tied under my dash above the kick panel. I looked it up and found it to be from a manufacturer named “bulldog security systems” I believe particular box this is tied into my door locking system. This could be a possible lead if is has something to do with the ignition which I suspect it very well could have.


Yes this very well could be the root of the issue, most alarm systems have an immobilizer built in. I would trace all the wires back to where they connect to the main harness and remove them / repair the main harness. Take photos of everything I'm very curious.

Also don't be afraid of the ECU they are more resilient than you think, also I have an extra working unit if you were to need it.
 
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Thank you sir, @SmokingRocks. I would like to apologize. I am out I’m the field farming and trying to respond on my phone which I am apparently not very skilled at. I’m am still learning how to use this forum as well.

I have checked your steps 1-6 of the spark branch and they have passed.

I will check the signals from the distributor to the ECM and follow your steps for that procedure.
 

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