FrazerJames Posted June 12, 2021 Author Share Posted June 12, 2021 What is the little purple band at the bottom of the scale for about the last five seconds representing? That’s meant to show you the IAC hitting 0. Link to comment Share on other sites More sharing options...
FrazerJames Posted June 13, 2021 Author Share Posted June 13, 2021 That’s meant to show you the IAC hitting 0. Got that NOS Motorcraft distributor, but it’s the weirdest thing. It’s completely locked up. Am I missing something? It won’t spin at all. I’m certainly not going to force it. The old one spins freely, so I’m just at a loss. Any thoughts? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted June 13, 2021 Share Posted June 13, 2021 That’s meant to show you the IAC hitting 0. Ah, so it's just the green line passes over the white border of the scale. That was quick! I can't say why the NOS distributor is frozen. Perhaps whatever lube it was built with is now petrified? Maybe the shaft itself has a bit of flash rust from condensation over the years? You might try inverting it and letting a bit of solvent or light oil like MMO soak in. That's probably the approach I would take. Whatever you do, don't force the vanes of the reluctor. If they get bent or snap off it's trashed. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted June 13, 2021 Share Posted June 13, 2021 Hi Dave, Yeah, even EFI System Pros aren’t sure what the issue is. Everything seems to be working correctly to them. Here’s an example of an effort to keep it running. http://forum.garysgaragemahal.com/file/n98871/8CBC140C-404C-44BC-99C7-CC58D98E90B2.png Your IAC spiked to try and maintain desired idle speed but that only happened after your RPM dropped off and your RPM started to drop off after your AFR started to go up. Did the AFR turn yellow/red when it started running bad losing rpm? I wonder if you might have a faulty O2 sensor. What ever caused this issue is a result of your AFR spiking up. Link to comment Share on other sites More sharing options...
FrazerJames Posted June 13, 2021 Author Share Posted June 13, 2021 Hi Dave, Yeah, even EFI System Pros aren’t sure what the issue is. Everything seems to be working correctly to them. Here’s an example of an effort to keep it running. http://forum.garysgaragemahal.com/file/n98871/8CBC140C-404C-44BC-99C7-CC58D98E90B2.png Your IAC spiked to try and maintain desired idle speed but that only happened after your RPM dropped off and your RPM started to drop off after your AFR started to go up. Did the AFR turn yellow/red when it started running bad losing rpm? I wonder if you might have a faulty O2 sensor. What ever caused this issue is a result of your AFR spiking up. That’s what I had thought as well, but I’m getting the same exact issue running open loop. No difference at all as far as I can tell. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted June 13, 2021 Share Posted June 13, 2021 That’s what I had thought as well, but I’m getting the same exact issue running open loop. No difference at all as far as I can tell. Thats why I am going to have mine tuned by someone that knows what they are doing. I can install the units but I cant make heads or tails out of the data logs to tell what is wrong. I can see whats going on but not sure whats causing it. I know a known problem with the sniper is with vibration the injector connectors can come undone but I think the only way to tell on that would be to see if all four injectors are still spraying when it starts stalling out. But the looking online I was just doing seems to indicate higher the AFR is the leaner it is and the lower it is the richer it is so if that is true you were going dead lean which is a sign of a failed O2 sensor, I read that they always go dead lean when the O2 sensor fails. Link to comment Share on other sites More sharing options...
FrazerJames Posted June 13, 2021 Author Share Posted June 13, 2021 That’s what I had thought as well, but I’m getting the same exact issue running open loop. No difference at all as far as I can tell. Thats why I am going to have mine tuned by someone that knows what they are doing. I can install the units but I cant make heads or tails out of the data logs to tell what is wrong. I can see whats going on but not sure whats causing it. I know a known problem with the sniper is with vibration the injector connectors can come undone but I think the only way to tell on that would be to see if all four injectors are still spraying when it starts stalling out. But the looking online I was just doing seems to indicate higher the AFR is the leaner it is and the lower it is the richer it is so if that is true you were going dead lean which is a sign of a failed O2 sensor, I read that they always go dead lean when the O2 sensor fails. I think I’m going to get mine tuned as well, but first I need to be able to be confident I can even take it to the gas station… it hasn’t moved yet. My understanding is that if you go open loop it doesn’t take into account any 02 readings. That’s how people get home when their 02 goes bad. Just pop it into open loop and you’re golden. I read that about the vibration as well. Something to chase down, I guess. I just have to think it’s something pre-Sniper at this point considering it’s doing the same stalling move. I mean, it feels like it’s just a fuel thing (which before the Sniper I thought was the issue - rusty tank and gunked up sender), but I’ve got all new tank, sender and lines as well as a gauge that shows it’s getting fuel perfectly fine (60PSI). At this point I believe it’s got to be something else because the issue hasn’t been resolved with the Sniper. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted June 13, 2021 Share Posted June 13, 2021 I think I’m going to get mine tuned as well, but first I need to be able to be confident I can even take it to the gas station… it hasn’t moved yet. My understanding is that if you go open loop it doesn’t take into account any 02 readings. That’s how people get home when their 02 goes bad. Just pop it into open loop and you’re golden. I read that about the vibration as well. Something to chase down, I guess. I just have to think it’s something pre-Sniper at this point considering it’s doing the same stalling move. I mean, it feels like it’s just a fuel thing (which before the Sniper I thought was the issue - rusty tank and gunked up sender), but I’ve got all new tank, sender and lines as well as a gauge that shows it’s getting fuel perfectly fine (60PSI). At this point I believe it’s got to be something else because the issue hasn’t been resolved with the Sniper. Yeah if you had this problem before the sniper its going to be something outside of the sniper. Carbs can actually mask many issues that EFI cant mask but if you had problems before then its going to be something outside of EFI, might be ignition related, could even be something mechanically wrong with the engine as well, holley stresses to make sure the engine is in good mechanical condition before installing their EFI. Link to comment Share on other sites More sharing options...
FrazerJames Posted June 13, 2021 Author Share Posted June 13, 2021 I think I’m going to get mine tuned as well, but first I need to be able to be confident I can even take it to the gas station… it hasn’t moved yet. My understanding is that if you go open loop it doesn’t take into account any 02 readings. That’s how people get home when their 02 goes bad. Just pop it into open loop and you’re golden. I read that about the vibration as well. Something to chase down, I guess. I just have to think it’s something pre-Sniper at this point considering it’s doing the same stalling move. I mean, it feels like it’s just a fuel thing (which before the Sniper I thought was the issue - rusty tank and gunked up sender), but I’ve got all new tank, sender and lines as well as a gauge that shows it’s getting fuel perfectly fine (60PSI). At this point I believe it’s got to be something else because the issue hasn’t been resolved with the Sniper. Yeah if you had this problem before the sniper its going to be something outside of the sniper. Carbs can actually mask many issues that EFI cant mask but if you had problems before then its going to be something outside of EFI, might be ignition related, could even be something mechanically wrong with the engine as well, holley stresses to make sure the engine is in good mechanical condition before installing their EFI. Oh, man, that would really suck. I’ve been working on this thing for 9 months slowly but surely. I got the distributor in (it did just lose all it’s lubrication - spun fine once I greased it up) and could get it to start and run for about 15 seconds before the same thing happens. I’m getting a ton of black soot and water out of the tailpipe now too so it’s just running crazy rich, I guess. Feels like I’m going backwards… Three weeks ago, I had it running for 20 minutes and was about to drive it… I think I’m at my end point here… Nothing left to do, but get it towed to have someone else take a shot at it. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted June 13, 2021 Share Posted June 13, 2021 Oh, man, that would really suck. I’ve been working on this thing for 9 months slowly but surely. I got the distributor in (it did just lose all it’s lubrication - spun fine once I greased it up) and could get it to start and run for about 15 seconds before the same thing happens. I’m getting a ton of black soot and water out of the tailpipe now too so it’s just running crazy rich, I guess. Feels like I’m going backwards… Three weeks ago, I had it running for 20 minutes and was about to drive it… I think I’m at my end point here… Nothing left to do, but get it towed to have someone else take a shot at it. Well, like I said, I don't think it is the fault of the distributor. And now you seem to have ruled out the pickup as a possibility. Im still !poking at your graph and trying to figure whether the chicken or the egg came first. I don't see the tach signal just vanish. (And I don't see it breaking up at all) I just see that IAC go to zero and then within five seconds the rpm drops form 1,000 to zero over a couple of seconds. Then the IAC spikes trying to recover. I don't know how the Sniper modulates the throttle. If this was a carb I'd say the throttle blade was completely shut and as soon as it came off the fast idle cam the engine stopped. If the idle air control is incapable of getting the revs down below 1,000 maybe there is an air leak somewhere? Link to comment Share on other sites More sharing options...
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