Mimic injecter pulse? ??
03-15-2017, 07:33 AM
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Mimic injecter pulse? ??
I am very hesitant to add a new thread only because I haven't completely stripped the wiring harness apart. Is there any way to mimic injector pulse from the distributor to the ECU like you can with a crankshaft sensor? And I've heard you can pulse the injectors from the ECU not sure if you use the IGT or if you use the polls number 10 and number 20 to the injectors. I did check voltage on poles number 10 and number 20 and had 12 volts which was puzzling I assumed I would get a ground reading. I did check the distributor pickup coils that I read about they did seem to Ohm out within spec I'm really fighting the urge to replace distributor as it is the only piece that has not been replaced. I have learned more about the Toyota electrical system than I ever thought I would thanks to the threads from yotatech I appreciate everyone's help. I am working on a 94 Toyota T100 3.0 it is giving my noid light an injector pulse but when I hook up a light with more resistance such as my 75 watt tester bulb then it does not show any pulse at all. I am beginning to think a bad wire but would it affect both Banks of injectors pole #10and ppole# 20 I assumed one side would be affected and not the other. I was told to load test my grounds never doing this before would my 75 watt test bulb be a sufficient load. This truck runs perfect if you force-feed through the throttle body. The only thing I can think of next is learning how to do a voltage drop test on my wiring system as was recommended just hoping there is an easier faster fix. Sorry for the long question hope I gave enough information to be useful any help would be appreciated
03-15-2017, 04:30 PM
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75 watt tester bulb? Even if you had a 7 1/2 watt bulb (which would be a VERY bright tester), it, too, would overwhelm the injector drive.
Does "force-feed through the throttle body" mean you are adding fuel (or starting spray) directly into the induction system? (Do you have the intake disconnected to do that?)
I'm not sure from your description what you are trying to do, or why. If the engine runs at all, then the you're getting spark, which means the distributor is generating the G and NE pulse. If the Noid light shows an injector pulse, you probably have one, and a tester light is not going to help matters. If you have the intake disconnected from the throttle body (to force feed or otherwise), then the fuel pump will NOT run, you will have no fuel pressure (even though the injectors are opening) and the engine will not run.
When you checked voltage on pins 10 and 20, was the engine not running? Was key-on? 12v (approx) is what you should have under those conditions (the spec is 9-14v, probably to take into account different states of battery voltage).
Does "force-feed through the throttle body" mean you are adding fuel (or starting spray) directly into the induction system? (Do you have the intake disconnected to do that?)
I'm not sure from your description what you are trying to do, or why. If the engine runs at all, then the you're getting spark, which means the distributor is generating the G and NE pulse. If the Noid light shows an injector pulse, you probably have one, and a tester light is not going to help matters. If you have the intake disconnected from the throttle body (to force feed or otherwise), then the fuel pump will NOT run, you will have no fuel pressure (even though the injectors are opening) and the engine will not run.
When you checked voltage on pins 10 and 20, was the engine not running? Was key-on? 12v (approx) is what you should have under those conditions (the spec is 9-14v, probably to take into account different states of battery voltage).
03-16-2017, 07:02 AM
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Thank you Scope 103 for replying the key was on when I was checking the poles number 10 and number 20 I was told you can ground those by tapping them and listening to the injector to see if it is operating but when I seen the voltage I was hesitant to do that afraid of burning something up and yes I do mean adding spray in through the intake and I am bypassing the fuel pump forcing it to run and I'm holding 50 pounds pressure at the fuel rail the injectors are definitely getting a pulse but the cylinders are staying bone dry I disassembled all of them thinking they might be plugged clean them put them back in and I can jump over to the injector and it will spray fuel out but when you plug them in and try to allow the ECU to operate even with the pulse I am not getting any fuel I was told the Noid light did not take any amperage to operate and injectors took more amperage i guess is what I was told so I figured a higher wattage bulb would mimic the injectors after doing this and more research I figured out this could damage the drivers my goal primarily was to tap a ground to polls 10 and 20 at the ECU to listen for the injectors to pulse everyone I talk to says if the Noid light is flashing the injectors are working but there is definitely no fuel coming out thank you very much for the help
03-16-2017, 08:42 AM
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Breathe, RACC, Breathe!
Okay, I know you're posting with your phone, but you've got to use some punctuation! Maybe a few "carriage returns." (are they still called that?)
At the risk of confusing matters, 50psi on the rail is way too high. http://web.archive.org/web/201003261...87fuelpump.pdf Of course, the problem that SHOULD cause is too-rich; the opposite of what you have.
You don't give your year, model, engine ... I assume it's a Toyota, but it makes a difference. The earlier second-gens used low-impedance injectors, and had a big resistor mounted under the hood. What I'm going to suggest won't work if you have those (in fact it might damage the injector).
Subject to the prior paragraph, I'd pull a spark plug or two, disconnect the corresponding injector, pressure the rail with the jumper, and put 12v on the injector. You should be able to hear it click, and probably hear it spray. If you happen to have the intake valve open (you can figure it out from firing order and the position of the crank, but it's not trivial) you should be able to see some fuel in the cylinder.
I wouldn't ground pin 10 or 20 when connected to the ECU. It might be an open-collector driver and that wouldn't hurt, but if that isn't the case you could damage the ECU.
If that doesn't work, you could use this setup https://www.yotatech.com/forums/f116.../#post52330847 and crank the engine (be careful the paper strips don't get pulled into the cylinder!!) If the injectors are opening the strips will be wet.
Okay, I know you're posting with your phone, but you've got to use some punctuation! Maybe a few "carriage returns." (are they still called that?)
At the risk of confusing matters, 50psi on the rail is way too high. http://web.archive.org/web/201003261...87fuelpump.pdf Of course, the problem that SHOULD cause is too-rich; the opposite of what you have.
You don't give your year, model, engine ... I assume it's a Toyota, but it makes a difference. The earlier second-gens used low-impedance injectors, and had a big resistor mounted under the hood. What I'm going to suggest won't work if you have those (in fact it might damage the injector).
Subject to the prior paragraph, I'd pull a spark plug or two, disconnect the corresponding injector, pressure the rail with the jumper, and put 12v on the injector. You should be able to hear it click, and probably hear it spray. If you happen to have the intake valve open (you can figure it out from firing order and the position of the crank, but it's not trivial) you should be able to see some fuel in the cylinder.
I wouldn't ground pin 10 or 20 when connected to the ECU. It might be an open-collector driver and that wouldn't hurt, but if that isn't the case you could damage the ECU.
If that doesn't work, you could use this setup https://www.yotatech.com/forums/f116.../#post52330847 and crank the engine (be careful the paper strips don't get pulled into the cylinder!!) If the injectors are opening the strips will be wet.
03-16-2017, 05:13 PM
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I apologize scope.
Can you tell I was excited. It's amazing how you get a pep in your step when someone throws you a life preserver. I am working on a 1994 t100, 3.0. I went staight to shop when I got home and ohmed all 6 injectors. All of them where 13.9 and 14. Was praying that one or two was different. Just for giggles I ran through the gourds again. The fuel pressure while trying to start varies from 45 to 49 psi. Someone told me the bandwidth could be off and it would have to be hooked up to the (machine). I guess I'll look for service manual and run through all sensers and specs on the ecu. 6 days under hood, 5 nights searching web, I think my braim is getting as fred as my truck. Thanks again scope!!!
Can you tell I was excited. It's amazing how you get a pep in your step when someone throws you a life preserver. I am working on a 1994 t100, 3.0. I went staight to shop when I got home and ohmed all 6 injectors. All of them where 13.9 and 14. Was praying that one or two was different. Just for giggles I ran through the gourds again. The fuel pressure while trying to start varies from 45 to 49 psi. Someone told me the bandwidth could be off and it would have to be hooked up to the (machine). I guess I'll look for service manual and run through all sensers and specs on the ecu. 6 days under hood, 5 nights searching web, I think my braim is getting as fred as my truck. Thanks again scope!!!
03-16-2017, 05:33 PM
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I did have a check engine code 22 when I jumped the odb1. Was told it was coolant temp, changed senser, no change. Pulled battery cable to reset code, code came back or did not reset. Also thought temperature senser wouldn't create no start issue. I'm so lost at this point.
03-17-2017, 12:25 PM
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New distributer with no change. Suspected it but had to try. Good news no more codes. Still no fuel
Taking my boys fishing this weekend, maybe I'll have an apiphany, (at least a well deserved break). The injectors will shoot fuel when you jump them manually.
Taking my boys fishing this weekend, maybe I'll have an apiphany, (at least a well deserved break). The injectors will shoot fuel when you jump them manually.
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03-17-2017, 12:43 PM
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i have to give you credit for doing all the right tests. Maybe with a fish on the line, you'll realize (epiphany) what you did wrong with the order. Or something.
Did you measure the fuel pressure at the FPR, or further back? (a possible location is at the CSI, or at the back right corner of the fuel rail.) The FPR is at the end of the rail, so pressure there is the best test. If you have a blocked fuel rail, you could have pressure in back but not at the injectors.
Since you are pretty sure the injectors work, and pretty sure you have enough fuel pressure, and pretty sure that you're getting some sort of pulse at the injectors, I suppose you could measure the pulse. Unfortunately, there isn't any decent way to do this without an oscilloscope. You could go really cheap https://www.aliexpress.com/item/DSO1...777588244.html , or for only a few dollars more, you could go really top-drawer: http://www.keysight.com/en/pcx-27595...0&cc=US&lc=eng (for the price of two visits to an ordinary mechanic, the Keysight is a laboratory-grade oscilloscope. I'm really cheap, but if I didn't already own a Tek, I know which one I'd get). At pin 10 you're looking for the ECU to pull the pin all the way to ground; at the injector the voltage drop in the lines means it only pulls down to a volt or two.
Good luck, and let us know what you find.
Did you measure the fuel pressure at the FPR, or further back? (a possible location is at the CSI, or at the back right corner of the fuel rail.) The FPR is at the end of the rail, so pressure there is the best test. If you have a blocked fuel rail, you could have pressure in back but not at the injectors.
Since you are pretty sure the injectors work, and pretty sure you have enough fuel pressure, and pretty sure that you're getting some sort of pulse at the injectors, I suppose you could measure the pulse. Unfortunately, there isn't any decent way to do this without an oscilloscope. You could go really cheap https://www.aliexpress.com/item/DSO1...777588244.html , or for only a few dollars more, you could go really top-drawer: http://www.keysight.com/en/pcx-27595...0&cc=US&lc=eng (for the price of two visits to an ordinary mechanic, the Keysight is a laboratory-grade oscilloscope. I'm really cheap, but if I didn't already own a Tek, I know which one I'd get). At pin 10 you're looking for the ECU to pull the pin all the way to ground; at the injector the voltage drop in the lines means it only pulls down to a volt or two.
Good luck, and let us know what you find.
03-21-2017, 06:58 PM
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Pulled both fuel rails, checked all 6 injectors, they worked great . Then stripped wiring harness apart looking for the crimp to the injectors. All 4 crimps look good as new, soldered them to make sure. Followed the harness to the valve cover wear it was grounded, cleaned and added a copper strap to the firewall where it goes to the intake ground. Put all of this back together including intake box,intake hose, and all vacuum lines. IT STARTED UP!!!! I think I wet myself alittle. Not sure what fixed it but the ground was the only real change I can see...
Now it is running really rough. Surging, no throttle response, pumping the throttle can get the rpms up but if you just push throttle down it stumbles. Checked codes again and now have 52, just found out is knock senser. Will be researching this tonight and starting tomorrow with timing checks . Thanks for all help and support, I am certain with yotatech and some patience ,maybe a drink or two, this too will be fixed . Did I mention it is running now. Waaaaaahoooooooo
Now it is running really rough. Surging, no throttle response, pumping the throttle can get the rpms up but if you just push throttle down it stumbles. Checked codes again and now have 52, just found out is knock senser. Will be researching this tonight and starting tomorrow with timing checks . Thanks for all help and support, I am certain with yotatech and some patience ,maybe a drink or two, this too will be fixed . Did I mention it is running now. Waaaaaahoooooooo
03-31-2017, 06:48 AM
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Real quick
knock senser didn't change a thing. Now I found that if you pull the vacuum line off of theEGR it runs fine. Put it back on and it almost dies. Put a timing light to it and with the vacuum lin unplugged it is 10 degrees and when you put it back on it goes to 32 degrees andruns horrible. So now back yotatech for more research. Thanks for all the help guys!!!!!!!!
knock senser didn't change a thing. Now I found that if you pull the vacuum line off of theEGR it runs fine. Put it back on and it almost dies. Put a timing light to it and with the vacuum lin unplugged it is 10 degrees and when you put it back on it goes to 32 degrees andruns horrible. So now back yotatech for more research. Thanks for all the help guys!!!!!!!!
