1991 4Runner No Spark
06-20-2017, 02:36 PM
#1
1991 4Runner No Spark
I have researched and researched. I really need a hand with this. I purchased this 1991 4Runner last week. It had a 1992 Toyota truck engine installed but they could never get it running. It did run prior to the swap. What I have done. I have replaced the fuel pump, filter and hooked everything up. I have checked all fuses. I have power on B1 and I do get Fuel Pressure when you try to crank it. I'm not getting spark. I do have power at the coil. I do get a spark by the test they showed by going to ground and doing a tap test.
So I read about checking the IGT and if it has Continuity between the ECU. What wire color is that. I have tried looking up diagrams and I keep coming up empty handed. I did read where one guy was not getting a check engine light. I also read to pull the plug from the ECU and ground the purple wire to ground with key on and you should get a check engine light. I do get a check engine light when I do that. But not when plugged in. What does that mean? It mentions checking IGT and E1 terminals when cranking.
Any help is appreciated. I feel like I'm close but need a little help.
So I read about checking the IGT and if it has Continuity between the ECU. What wire color is that. I have tried looking up diagrams and I keep coming up empty handed. I did read where one guy was not getting a check engine light. I also read to pull the plug from the ECU and ground the purple wire to ground with key on and you should get a check engine light. I do get a check engine light when I do that. But not when plugged in. What does that mean? It mentions checking IGT and E1 terminals when cranking.
Any help is appreciated. I feel like I'm close but need a little help.
Last edited by CaglezXJ; 06-20-2017 at 02:37 PM.
06-20-2017, 02:48 PM
#2
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I assume the test "they showed" (??) is to tap the "minus" lead of the coil to ground. That will test the coil, but it can also burn it out. So be careful.
What is "B1" on which you have voltage? (power?)
With key-on, is the CEL on? You've tested the bulb (by grounding the violet wire at the ecu (connector E4 pin 5)), but the ECU is supposed to ground that pin with key-on (engine off).
Here's what the IGT is, and how you can check it: https://www.yotatech.com/forums/f116...gniter-287857/
What is "B1" on which you have voltage? (power?)
With key-on, is the CEL on? You've tested the bulb (by grounding the violet wire at the ecu (connector E4 pin 5)), but the ECU is supposed to ground that pin with key-on (engine off).
Here's what the IGT is, and how you can check it: https://www.yotatech.com/forums/f116...gniter-287857/
06-20-2017, 03:56 PM
#3
B+ sorry. Been a long day of troubleshooting and yard work mixed in. So with the above statement,the computer should ground it. What's the best way to check my ECU? What's the best way to see if it's grounded properly?
I have even tried putting the 4Runner ECU in just to see if it helps and it does no different.
I have even tried putting the 4Runner ECU in just to see if it helps and it does no different.
Last edited by CaglezXJ; 06-20-2017 at 04:33 PM.
06-23-2017, 09:34 AM
#4
I checked my ground to E1 and it's good. I checked 12v at ECU and it's good. I opened the ECU and I don't see anything blown or burned. Is there something that comes directly from my ignition switch that might be keeping the computer from working? I did have to remove the key lock pin the other day because the key would not work. Found online that the 2 wire lock can be removed. I do get my EFI relay energized when the key is on and I do have 12v on the hot terminal. Checked relay and it is fine and passes power when the key is on. Anyone have any ideas?
