Injectors won't pulse not getting power
- Thread starter Backyardmechanic1
- Start date
We tested with a noid light and got nothing then we used a test light on positive side of injector plug and grounded to the body and test light lit up so there's power to the harness but it's not getting the signal to turn on
Not much left to test. Check for continuity from injector -ve side to ECU connector.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=46
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=46
Very true, not much left.
He could test resistance to ground from pin E01, and E02, which are the ground pins used by the injector drivers.
Depending on if you have the yellow ECU connectors, Test pin 5, and pin 10 to ground.
If you have the Grey ECU connectors the test pin 13, and pin 26 to ground.
Testing these will verify that the harness is ok. Though due to the fact that they are redundant, failure here is highly unlikely. But it is something to check.
He could test resistance to ground from pin E01, and E02, which are the ground pins used by the injector drivers.
Depending on if you have the yellow ECU connectors, Test pin 5, and pin 10 to ground.
If you have the Grey ECU connectors the test pin 13, and pin 26 to ground.
Testing these will verify that the harness is ok. Though due to the fact that they are redundant, failure here is highly unlikely. But it is something to check.
Would I be better off just getting an ecu and harness out of a 5 speed and getting rid of the at ecu and harness
I would verify that I needed one or the other, before spending the money. There is nothing physically or operationally wrong with running an auto ECU and/or harness on a 5 speed(but not the other way around, obviously). It has been done before and is quite common as used 5 speed harnesses in good condition are hard to come by. And you can run a five speed harness with an auto ECU or a 5 speed ECU with an auto harness.
Not really, the injector circuit itself is pretty basic. You have 12v switched from the ignition key that goes to the injector resistor pack gets split into three lines(the injectors are batch fired). Since you have tested 12v at the injectors this part of the harness is good. The other half of the circuit has three lines that go directly to the ECU. And then two redundant lines come out of the ECU and go to ground. That is a total of five wires for you to test to see if the harness is good.
If you have a Yellow plug ECU, test continuity to the negative side of injector:
No.1 - No.4 to pin 4
No.2 - No.6 to pin 9
No.3 - No.5 to pin 8
If you have a Grey plug ECU, test continuity to the negative side of injector:
No.1 - No.4 to pin 12
No.2 - No.6 to pin 11
No.3 - No.5 to pin 25
Then test the two wires I mentioned a few posts up and thats it. Five wires and you can rule out your harness as a problem.
If you have a Yellow plug ECU, test continuity to the negative side of injector:
No.1 - No.4 to pin 4
No.2 - No.6 to pin 9
No.3 - No.5 to pin 8
If you have a Grey plug ECU, test continuity to the negative side of injector:
No.1 - No.4 to pin 12
No.2 - No.6 to pin 11
No.3 - No.5 to pin 25
Then test the two wires I mentioned a few posts up and thats it. Five wires and you can rule out your harness as a problem.
Ok we're gonna try that right now and are there any relays or sensors that could possibly be bad that would cause this
If you have a continuous 12v on pin 2(positive side) at the injector connector with the key on. And you trust the reading your noid tester is giving you then no.
P.S. That 'no' is based upon the rest of the information you provided, no codes and the motor runs with starter fluid, ect. This indicates that any sensors that are involved in the process are operating properly, and not the issue. I add this to dissuade anybody who might pop in here and mention that this or that could cause the problem without fully reading the previous posts and troubleshoots that has gone on. To help keep the thread clean and constructive.
P.S. That 'no' is based upon the rest of the information you provided, no codes and the motor runs with starter fluid, ect. This indicates that any sensors that are involved in the process are operating properly, and not the issue. I add this to dissuade anybody who might pop in here and mention that this or that could cause the problem without fully reading the previous posts and troubleshoots that has gone on. To help keep the thread clean and constructive.
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So we tested all those and it's all working right but now I'm getting a code 22 what does that mean
The code indicates a fault with the ECU's water temp sensor, or associated wiring. The first thing I would try is to pull the 15A EFI fuse for 30sec, located in the fuse box in the engine compartment. This will clear the code, then try to start the engine. After which, check to see if the code returns.
If the code does return test the water temp sender according to this page:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=113
If the code does return test the water temp sender according to this page:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=113
No, it would still start, enrichment would be off though. The code 22 could(emphasis on the could) be a ghost of a faulty ECU. A test of the temp sender would tell us if it is truly bad. But going back to the original injector issue, since we have tested all other parts of the circuit all that is really left is the ECU itself, the TCCS. The thing is, the TCCS is pretty robust. A failure is pretty rare. Has it been dropped, soaked or shocked?
Backyardmechanic1;1973245 said:
Your claims are not possible if the car runs with starting fluid. The PCM provides the ground path for the injectors, power is fused ignition and cranking. If it runs with starting fluid, it will run with gasoline. The only other choice is you are not getting power to the injectors like you claim in this thread. There are no other choices. If you did not have spark, the PCM would not provide a ground for the injectors. But since you say it ran on starting fluid, you are not getting fuel.
This is the circuit.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=46
Code 22 will cause hard cold starting since it fail safes to 80C coolant temperature. BUT, it would not cause the injectors to not fire, and the engine will run, just poorly when cold.
Ok I'm completely lost on this car no matter what I try I can't get the injectors to work I've found a few other forums with the same issue but no one has posted weather they have solved it or not I've had the car for 2 months and it ran when I got it but the block was no good so I got a new one and rebuilt it so I'm pretty sure the ecu is fine I've also seen on another forum that there is something with these cars that if something is wrong there is a safety thing that won't let it start if that makes any sense
Did you check the wiring from the injectors to the ECU for continuity?
There is not a safety thing that you speak of. The fuel pump is energized when the key is in start through the COR relay, its hard wired. Once you release the key if you have airflow the FP stays energized.
There is not a safety thing that you speak of. The fuel pump is energized when the key is in start through the COR relay, its hard wired. Once you release the key if you have airflow the FP stays energized.
I had him check those and he said they were ok. Tested the two redundant rails E01, E02 and showed good from ECU to chassis ground. Really, we are running out of possibilities based upon available information. We've started from possible causes and are all the way to improbable at this point.