SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 New milestone, boys! I had 12V at FP connector, with fuel pump disconnected. Will FIRE without fuel in TBI, but will not stay running. I'm slowly becoming more convinced (X) = Injector. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 HELL YES! Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 Just now, eaglescout526 said: HELL YES! Test Light shines bright, also! Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 I don't know how else to test the injector but is it trying to start better than before? Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 1 minute ago, eaglescout526 said: I don't know how else to test the injector but is it trying to start better than before? Well, thanks to all the testing, the battery voltage has diminished a bit. Sits at roughly 12.1V. Still FIRES the engine, but the cranking seems a bit rough probably because of the voltage. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 Needs one good FIRE to get the alternator charging that battery. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 Battery probably deserves a good trickle charge. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 Just now, eaglescout526 said: Battery probably deserves a good trickle charge. Yeah, should probably drop it off at an auto parts store tomorrow. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 Well, I think we may have come to a halt for the time being! The only issue remaining, at least I believe, is the fuel injector. I can try to timing light trick again to see if we can see a spray pattern, but other than that, the other tests seemed to check out. And like I've said, I have really seen a spray out of it at all. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 It could be the injector at this point. I think the injector tries to spray but doesn't. Like looking at that timing light kinda showed that it barely sprayed a sneeze of fuel. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 18 minutes ago, eaglescout526 said: It could be the injector at this point. I think the injector tries to spray but doesn't. Like looking at that timing light kinda showed that it barely sprayed a sneeze of fuel. https://drive.google.com/open?id=15VdMClg5f8gGDGqYZBlPiWAanOs-FNwU Yeah, I don't really see a lot going on. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 Damn does she want to start. Well we have no way of testing the ECU without the proper computer and the noid light seemed to go dim but I can't say much for it "pulsing". Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 2 minutes ago, eaglescout526 said: Damn does she want to start. Well we have no way of testing the ECU without the proper computer and the noid light seemed to go dim but I can't say much for it "pulsing". Well like you guys said, these ECUs are rather resilient and to find them being the issue as a last resort right? I've seen things here and there about pulling fuel injectors from GM motors, but the different spray rates apply. You well versed in this topic? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 Correct on the ECU, just would hate to see ya plop down $100 for an injector when the ECU isn't switching it like it is programmed to. Last I recall AMC used GM's fuel injector for the TBI 2.5L, but for spray rates, this is the first ive heard of it. If there are different part numbers for say the TBI V8 and the TBI I4 by GM, then that would indicate something as far as spray for the injector. But if the numbers are the same, then there probably isn't any significance in the spray patterns. But TBI tech lasted what? A decade before the first MPFI systems to come into play, so probably not much advancement in the TBI department. Well from a quick research I didn't see anything about GM TBI's and their spray patterns. Some goofball posted about testing his injector by "pulsing" it but of course he didn't say how he pulsed it. Another guy said he just had his give up the ghost to where it wouldn't fire anymore(like yours) and others say it could be gummed up and need a cleaning. But hey if you throw in a 90's 350ci TBI injector, I don't see anything changing as the ECU controls the injector pulses but it could have a wider spray pattern but most just show a conical pattern. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 2 minutes ago, eaglescout526 said: Correct on the ECU, just would hate to see ya plop down $100 for an injector when the ECU isn't switching it like it is programmed to. Last I recall AMC used GM's fuel injector for the TBI 2.5L, but for spray rates, this is the first ive heard of it. If there are different part numbers for say the TBI V8 and the TBI I4 by GM, then that would indicate something as far as spray for the injector. But if the numbers are the same, then there probably isn't any significance in the spray patterns. But TBI tech lasted what? A decade before the first MPFI systems to come into play, so probably not much advancement in the TBI department. Well from a quick research I didn't see anything about GM TBI's and their spray patterns. Some goofball posted about testing his injector by "pulsing" it but of course he didn't say how he pulsed it. Another guy said he just had his give up the ghost to where it wouldn't fire anymore(like yours) and others say it could be gummed up and need a cleaning. But hey if you throw in a 90's 350ci TBI injector, I don't see anything changing as the ECU controls the injector pulses but it could have a wider spray pattern but most just show a conical pattern. Hmm....well, it is a 30 year old injector. Is there a way to attempt to ungum it? Does fuel injector cleaner actually work? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 It probably does work, I know theres snake oil out there but I'm not sure if injector cleaner is among the snake oil. I bet the sonic cleaning process could help with ungumming it. I think I will take the spare injector I have and see how exactly it pulses and see if we can get the same results. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 2 minutes ago, eaglescout526 said: It probably does work, I know theres snake oil out there but I'm not sure if injector cleaner is among the snake oil. I bet the sonic cleaning process could help with ungumming it. I think I will take the spare injector I have and see how exactly it pulses and see if we can get the same results. Sounds good to me. Link to comment Share on other sites More sharing options...
Ωhm Posted May 9, 2020 Share Posted May 9, 2020 To me, you guys burn the midnight oil (timezone thing). I always wake up to pages of good solid testing. Anyway Cruiser has a CPS tip out there. Drill the CPS mounting holes out a little larger. This moves the tip of the CPS closer to the pickup wheel, increasing signal strength. RENIX CPS TESTING AND ADJUSTING A little trick for increasing the output of your CPS is to drill out the upper mounting hole to 3/8″ from the stock 5/16″, or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 1 hour ago, Ωhm said: To me, you guys burn the midnight oil (timezone thing). I always wake up to pages of good solid testing. Anyway Cruiser has a CPS tip out there. Drill the CPS mounting holes out a little larger. This moves the tip of the CPS closer to the pickup wheel, increasing signal strength. RENIX CPS TESTING AND ADJUSTING A little trick for increasing the output of your CPS is to drill out the upper mounting hole to 3/8″ from the stock 5/16″, or slot it so the CPS bracket rests on the bell housing when pushed down. Then, when mounting it, hold the CPS down as close to the flywheel as you can while tightening the bolts. I will definitely need to do that since my output for the CPS is minimal. Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 Well, I tried testing the injector and got no where. Just a couple small electrical sparks, so I am not sure how the ECU does it but I didn't hear a click or pulse or anything from the injector. Maybe if fuel was around it or in the rail it might do something but that can't be confirmed. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 3 hours ago, eaglescout526 said: Well, I tried testing the injector and got no where. Just a couple small electrical sparks, so I am not sure how the ECU does it but I didn't hear a click or pulse or anything from the injector. Maybe if fuel was around it or in the rail it might do something but that can't be confirmed. Why not just throw it in your MJ? Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 Well I was more or less trying to see if there is a way to bench test the injector, but I could very well throw it in, don't like the rust I got on it but that's what I get for relying on the O-rings for a good seal. But its only surface rust. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 Just now, eaglescout526 said: Well I was more or less trying to see if there is a way to bench test the injector, but I could very well throw it in, don't like the rust I got on it but that's what I get for relying on the O-rings for a good seal. But its only surface rust. Yeah, hindsight seems to really get me on here. Once I posted (yet again), i realized you were trying to figure out a bench test for me. Ha! Link to comment Share on other sites More sharing options...
eaglescout526 Posted May 9, 2020 Share Posted May 9, 2020 Lol. Like I said, all it does is spark when I ground it out. But I didn't try the other orientation as that shouldn't matter. Link to comment Share on other sites More sharing options...
SoCalManche Posted May 9, 2020 Author Share Posted May 9, 2020 Well I tried the different orientation, and it was same start-up, so I agree with that. Link to comment Share on other sites More sharing options...
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