Mr. Anderson Posted August 15, 2013 Share Posted August 15, 2013 I have an interesting misfire condition occurring. The miss is on injector 3, and the injector was not opening and closing. I took a stethoscope and was able to hear all of the injectors clicking except for #3. I replaced and reattached everything and the injector still isn't clicking. I tried a different injector but got the same results. I suspect a possible wiring issue. Does anyone have any idea what I can test or check next? :confused: Link to comment Share on other sites More sharing options...
NCReatta Posted August 15, 2013 Share Posted August 15, 2013 It's likely to be a wiring issue. Luckily, the injector harness is easy to replace in an '89. You have one large plug back near the power steering pump that disconnects it from the rest of the harness. Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 15, 2013 Author Share Posted August 15, 2013 That's good to know. But, how can I test to see how far back the problem is in the wires? Also, I should mention that I am getting no codes from this. Link to comment Share on other sites More sharing options...
Ronnie Posted August 15, 2013 Share Posted August 15, 2013 It's possible you have a bad ECM that is not sending a ground signal to open the injector. Check to see if one of the wires has power on it at all times. Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 15, 2013 Author Share Posted August 15, 2013 It's possible you have a bad ECM that is not sending a ground signal to open the injector. Check to see if one of the wires has power on it at all times.That's what I was wondering too.Ok, so on injector #3, there are two wires; a black/pink wire, and a brown wire. According to the FSM, the brown wire has power, and it does on my car. I am not sure how to check the other wire. I am assuming this one is a ground.But, like you said, it could be a bad ECM, so I need to make sure the wiring is good before I start messing with computers. Link to comment Share on other sites More sharing options...
Ronnie Posted August 15, 2013 Share Posted August 15, 2013 The injector opens when it gets a gound signal from the ECM. There is a tester called a noid light that can be connected to the harness to tell you if the injector is getting a signal. They are in The Reatta Store but you might be able to rent one at the auto parts store. It won't tell you if the problem is the ECM or a bad harness. If you don't get the signal with the noid light I would suspect the ECM. The best way to know for sure it to swap the ECM with one known to be good. Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 15, 2013 Author Share Posted August 15, 2013 That makes sense. I will see if I can get a noid light for testing and report back when I have all of my information. Thanks for all the help and info so far everybody! Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 16, 2013 Author Share Posted August 16, 2013 Ok, so I hooked up the harness to a noid light and the light indicated everything was working fine. I then hooked everything back up and took it for a lengthy drive. After about ten minutes, the missing quit, and everything ran smoothly for the rest of the drive. Upon returning, I took a listen to the injectors and found that all of them were clicking, even the one that was giving me trouble before. Hopefully my problems have solved themselves for now. Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 16, 2013 Author Share Posted August 16, 2013 (edited) The same problem came back when I started the car this morning. It always seems to stop after about ten minutes of driving though. Is this a possible ECM issue now?Edit: just retested the injector. It appears to turn off and on as pleases.Edit #2: just forced the injector to ground when it was missing. Got it to click, and after I did this a few times it killed the engine (probably because my timing wasn't right). Now it has worked right for the past few start-ups. Edited August 16, 2013 by Mr. Anderson retested (see edit history) Link to comment Share on other sites More sharing options...
Guest Mc_Reatta Posted August 16, 2013 Share Posted August 16, 2013 Sounds like you have a broken wire or bad connector at that injector, or the injector is going bad.Cheapest way to figure it out would be to swap that injector with an ajacent one and see what happens.Simplest way would probably be to splice in a new connector and pigtail and hope problem is solved. But that costs money, tears up the harness, and may not solve the problem if it is the injector. Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 16, 2013 Author Share Posted August 16, 2013 The injector in question was just installed yesterday, and it is the second one I tried on the car. Also, this problem is only on injector #3, not any of the other ones. I took a noid light to the plug again. This time, I tried it when the injector wasn't clicking, and I found that the light did not light up all of the time. After a little bit the light would flash for a little, but then it would stop flashing again. I could take a look at the harness and see if the connection is bad, but could this possibly be ECM related as the ECM sends the ground signal to the injectors? Link to comment Share on other sites More sharing options...
TexasJohn55 Posted August 16, 2013 Share Posted August 16, 2013 (edited) The same problem came back when I started the car this morning. It always seems to stop after about ten minutes of driving though. Is this a possible ECM issue now?Edit: just retested the injector. It appears to turn off and on as pleases.Edit #2: just forced the injector to ground when it was missing. Got it to click, and after I did this a few times it killed the engine (probably because my timing wasn't right). Now it has worked right for the past few start-ups.Grouding the circuit is not a recommended practice. The one time connection for a millisecond is not harmful but any longer may overload the circuit and component also. If the circuit is a PWM circuit, direct current draws a tremendous amount of current in the circuit which it is not designed for and can cause the "smoke to leak out". Everyone knows that electronics are sealed units and once the smoke leaks out, they are no good. Your engine likely died because the computer saw an overload on the injector driver circuit and turned it off. Your problem, as others have mentioned is likely a bad connection or wiring from the computer to the engine on that injector circuit. You will need to do a "wiggle test" on the harness and connectors while engine is running to find where the problem is. You can also hook up an ohmmeter to both ends for continuity and do the wiggle test. Good luck.Don't forget there are 2 circuits to trace for the injector. You may also have to check both circuits for intermittent short to ground while wiggling wires. Yes, a short to ground on the ground wire will cause a problem because the ECM can not control injection. The ground is not grounded, it is a return controlled by the ECM. Edited August 16, 2013 by TexasJohn55 (see edit history) Link to comment Share on other sites More sharing options...
Mr. Anderson Posted August 20, 2013 Author Share Posted August 20, 2013 Here's an update. I took an ohmmeter to the wires and did the wiggle test and saw no difference or strangeness in the wiring. I decided to try my luck at replacing the ECM. I took a chance and bought one from Autozone and installed it. After installation, the car runs fantastic, and the misfire went away at the first start-up. So far, everything is normal with the ECM, and hopefully this has solved my problem. Thanks for all of your help and information with this! Link to comment Share on other sites More sharing options...
TexasJohn55 Posted August 20, 2013 Share Posted August 20, 2013 Hoo rah! Fingers crossed. Check back in in a week or two. Link to comment Share on other sites More sharing options...
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