eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Basically like fuel was just trickling down the TB. Or kinda like when you have fuel in a carb and enough comes out and the engine kinda catches but its not enough to keep going? Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 3 minutes ago, eaglescout526 said: Basically like fuel was just trickling down the TB. Or kinda like when you have fuel in a carb and enough comes out and the engine kinda catches but its not enough to keep going? Yes, I can take a video if you want. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Hold off on that for a moment. I remembered something from when I rebuild my throttle body. If you were to remove the injector there are two holes, one for input and the other for return. I am wondering if we can observe how the fuel comes out from there. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 7 minutes ago, eaglescout526 said: Hold off on that for a moment. I remembered something from when I rebuild my throttle body. If you were to remove the injector there are two holes, one for input and the other for return. I am wondering if we can observe how the fuel comes out from there. If fuel injector is removed (I'm assuming keep it attached to harness when key ON), will fuel continue to flow since pressure won't establish? Just trying to have a game plan before I do this. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Ah good, you caught the keeping it plugged into the harness. I thought about mentioning that. Well when it does the prime, fuel will come out of the hole in the TB for the injector for a second. When you go to crank or apply voltage to the pump it should just come out, we aren't looking for pressure, more or less seeing if fuel flow is obstructed or not and seeing if maybe the injector could be at fault. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 37 minutes ago, eaglescout526 said: Ah good, you caught the keeping it plugged into the harness. I thought about mentioning that. Well when it does the prime, fuel will come out of the hole in the TB for the injector for a second. When you go to crank or apply voltage to the pump it should just come out, we aren't looking for pressure, more or less seeing if fuel flow is obstructed or not and seeing if maybe the injector could be at fault. You will love this. https://drive.google.com/open?id=14t9FgQ1lDAHVLMLw5rZvC8iV2UDPbyOR Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Lol lets not do that again shall we? No blockage in the fuel line so that's good, pretty cool to learn that it just pours right out during crank. So I'm not sure how the ECU controls the injector, my guess is the ECU has a switch or control chip inside that switches on/off for the ground of the injector to pulse. Other than checking for the Ωhms resistance, I am not sure how else to test it. I mean it was tough to tell if the ECU was truly switching the injector with the noid. I might have to take a test light and see if I can see what this dimming looks like. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 1 minute ago, eaglescout526 said: Lol lets not do that again shall we? No blockage in the fuel line so that's good, pretty cool to learn that it just pours right out during crank. So I'm not sure how the ECU controls the injector, my guess is the ECU has a switch or control chip inside that switches on/off for the ground of the injector to pulse. Other than checking for the Ωhms resistance, I am not sure how else to test it. I mean it was tough to tell if the ECU was truly switching the injector with the noid. I might have to take a test light and see if I can see what this dimming looks like. So there's two possible orientations on how to place the injector in the throttle body. Does the orientation matter? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 I don't think the orientation matters for the injector, at least I haven't seen anything that denotes orientation for it. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 1 minute ago, eaglescout526 said: I don't think the orientation matters for the injector, at least I haven't seen anything that denotes orientation for it. That was the only thing I had, haha. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 So unless the ECU isn't switching the injector fully, or the injector isn't wanting to operate correctly, it just won't fire or at least it tries to. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 2 minutes ago, eaglescout526 said: So unless the ECU isn't switching the injector fully, or the injector isn't wanting to operate correctly, it just won't fire or at least it tries to. It won't FIRE in terms of everything being hooked up properly. Unless fuel is added to TBI. Correct. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Correct, we have ruled out just about every damn thing except two things. Is the ECU switching the injector? Or is the injector faulty and not pulsing fuel like it should? We have kinda ruled out the fuel pump but not exactly. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 3 minutes ago, eaglescout526 said: Correct, we have ruled out just about every damn thing except two things. Is the ECU switching the injector? Or is the injector faulty and not pulsing fuel like it should? We have kinda ruled out the fuel pump but not exactly. So obviously I used the noid light to distinguish what we are saying is a pulsating dim light. Is there any other way to test the wiring besides that? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 We could test for resistance and voltage, Supposedly the wiring shows it is apart of that FP relay splice "K" so it should have either the 10V(from earlier) or battery voltage and I would guess that the ECU controls the ground for the pulse. I can try to do a test light tomorrow and see if I can get that dim pulse and rewatch your video to see. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 15 minutes ago, eaglescout526 said: We could test for resistance and voltage, Supposedly the wiring shows it is apart of that FP relay splice "K" so it should have either the 10V(from earlier) or battery voltage and I would guess that the ECU controls the ground for the pulse. I can try to do a test light tomorrow and see if I can get that dim pulse and rewatch your video to see. I wonder if fixing those dipstick grounds shifted the voltage. KEY ON & FP harness unplugged: Pin 30 = Batt voltage Pin 87 & Splice K = 0.5V KEY ON & FP harness plugged: Pin 30 = Batt voltage Pin 87 & Splice K = 0.01V What the hell is going on? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 But weren't we seeing 10V earlier today at those splices? Wait did you get the 10V with the relay or the jumper? Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 Just now, eaglescout526 said: But weren't we seeing 10V earlier today at those splices? Wait did you get the 10V with the relay or the jumper? I tested the pin 87 directly when I did tests, so nothing was in socket. Yes, those readings were taken earlier before I re-crimped the wires I believe. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Yeah but with key on we won't see any voltage run down the line for start up phase. Power will be present for one second and them gone. It won't be until the engine is running(or relay jumped) when we will see constant power at the splice and else where in that line. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 1 minute ago, eaglescout526 said: Yeah but with key on we won't see any voltage run down the line for start up phase. Power will be present for one second and them gone. It won't be until the engine is running(or relay jumped) when we will see constant power at the splice and else where in that line. That's weird. I'm pretty sure I tested 87 without a jumper and it hit 10V. Now I have to go check again. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Alright once you get a reading, lets get back at it tomorrow. Also ive been studying the 86, 87 and 88 electrical schematics. Everything connected to the ECU connector is the same for all years, so I would imagine the 87-90 years could be an upgrade over the 86 ECU. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 Lol, yeah. I just tried to jumper the relay without the FP connector plugged in, and started worrying on why there wasn't any fuel being pushed; it's definitely time for a break. Voltage at Splice K was Batt voltage with jumper. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Ok so I went a did a little test of my own with the injector harness. I used a test light and tried a couple things. I attached the clip to power of the battery and found one is ground and remains lit until the engine cranks. I tried the other prong of the injector harness and got nothing, not even a dim light. Switched the clip to ground post and got nothing on the prong that lit up and nothing during crank. Moved to the next one and got nothing during crank, course its so bright outside that even if the test lamp did dimly light, I didn't see it. But if I recall, your test noid remained lit constantly, I'm still waiting on my noid light to test it better than using a test light. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 7, 2020 Author Share Posted May 7, 2020 43 minutes ago, eaglescout526 said: Ok so I went a did a little test of my own with the injector harness. I used a test light and tried a couple things. I attached the clip to power of the battery and found one is ground and remains lit until the engine cranks. I tried the other prong of the injector harness and got nothing, not even a dim light. Switched the clip to ground post and got nothing on the prong that lit up and nothing during crank. Moved to the next one and got nothing during crank, course its so bright outside that even if the test lamp did dimly light, I didn't see it. But if I recall, your test noid remained lit constantly, I'm still waiting on my noid light to test it better than using a test light. Yes, it stayed lit the entire time, and when cranking it was a constant dim. I got lucky and found someone on Craigslist selling a new-in-box timing light for $20 and just picked it up. This test would still help, yes? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 7, 2020 Share Posted May 7, 2020 Timing test should help with that too, if the injector is spraying at all. I have a spare injector but am unsure if it works or not. I think Ωhm might know more about the injector timing light test than I would. Link to comment Share on other sites More sharing options...
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