grumpin Posted January 14, 2019 Share Posted January 14, 2019 Ok, what's the status? How's your mood? Hang in there buddy, there's light at the end of the tunnel. And, I meant it when I asked for a bit of explanation as to what you did when in that long video. It might help us understand why the tone changed and, therefore, what the issue(s) is/are. It'll be great when you get it all ironed out! Link to comment Share on other sites More sharing options...
Ferdinand Posted January 15, 2019 Author Share Posted January 15, 2019 Thanks for the encouragement guys. This is really becoming a battle of the will... SO after talking this thing to death with anyone and everyone I could find in addition to all the wisdom here, I thought we had it figured down to fuel delivery. AND, with the rebuilt carb being one large suspect variable I reached out and found a friend with a known good Edelbrock 500 in a box and we bolted it up and it ran like a dream! (although we didn't do the "under load" test. I thought for sure for how smooth it ran and took throttle stabs, surely it was the carb. So, I pulled the trigger and bought a new one. Here is the result: Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 15, 2019 Share Posted January 15, 2019 Thanks for the encouragement guys. This is really becoming a battle of the will... SO after talking this thing to death with anyone and everyone I could find in addition to all the wisdom here, I thought we had it figured down to fuel delivery. AND, with the rebuilt carb being one large suspect variable I reached out and found a friend with a known good Edelbrock 500 in a box and we bolted it up and it ran like a dream! (although we didn't do the "under load" test. I thought for sure for how smooth it ran and took throttle stabs, surely it was the carb. So, I pulled the trigger and bought a new one. Here is the result: BUMMER! Well, lemme think. The fact that the 500 "like a dream" suggests that is is the carb. You didn't do an "under load" test - does that mean you didn't put it in gear or just didn't drive it? So, you have a brand new carb, and it didn't run as well as the 500. But, was it better or different than your original carb? The issue with stumbling on throttle-up may be the accelerator pump adjustment. Or, the pump may be bad. I'd play w/the adjustment and, if needed, pull the cover on the carb to see what's inside. Link to comment Share on other sites More sharing options...
grumpin Posted January 15, 2019 Share Posted January 15, 2019 BUMMER! Well, lemme think. The fact that the 500 "like a dream" suggests that is is the carb. You didn't do an "under load" test - does that mean you didn't put it in gear or just didn't drive it? So, you have a brand new carb, and it didn't run as well as the 500. But, was it better or different than your original carb? The issue with stumbling on throttle-up may be the accelerator pump adjustment. Or, the pump may be bad. I'd play w/the adjustment and, if needed, pull the cover on the carb to see what's inside. What about the EGR valve? Just trying to think of what would make it stumble and/or stall. Link to comment Share on other sites More sharing options...
Steve83 Posted January 15, 2019 Share Posted January 15, 2019 What about the EGR valve? Just trying to think of what would make it stumble and/or stall. Read this caption, especially the 2nd paragraph under "Overview": https://supermotors.net/getfile/826382/thumbnail/egrtubesv8.jpg So that means the EGR is normally "off" (regardless if it's controlled by an EEC or by a complicated vacuum system), which means it's safe to temporarily disable it to eliminate it as a possible cause for your idle concerns. A simple piece of Aluminum foil slipped between the valve & its adapter plate (if yours is built that way) is usually enough to block all flow at idle. Link to comment Share on other sites More sharing options...
Ferdinand Posted January 15, 2019 Author Share Posted January 15, 2019 What about the EGR valve? Just trying to think of what would make it stumble and/or stall. So, in the process of trying to build a very simple straight forward vehicle to have for years to come and since nearly all of the emissions and vacuum related components had melted into large clumps, I have opted for the simplest configuration under the hood I could muster. No EGR, removed all Thermactor pump pieces and parts, removed head cross tube, etc. Pretty simple. Which is why I feel like I am missing something right in front of my eyes Because there really isn't that much going on. The only thing my carb is connected to at the moment is the power brake booster and the transmission module. I was told by several "gurus" to not connect my vacuum advance on the distributer yet, though I have had that connected for most of the past videos. It is off now. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 15, 2019 Share Posted January 15, 2019 So, in the process of trying to build a very simple straight forward vehicle to have for years to come and since nearly all of the emissions and vacuum related components had melted into large clumps, I have opted for the simplest configuration under the hood I could muster. No EGR, removed all Thermactor pump pieces and parts, removed head cross tube, etc. Pretty simple. Which is why I feel like I am missing something right in front of my eyes Because there really isn't that much going on. The only thing my carb is connected to at the moment is the power brake booster and the transmission module. I was told by several "gurus" to not connect my vacuum advance on the distributer yet, though I have had that connected for most of the past videos. It is off now. I have checked for any vacuum leaks - none. I have metered out my plug wires - all good. I have checked my firing order again - correct. I pulled temps on my cylinders which is another indicator that something is just not right. They are as follows: 1 - 709 2 - 590 3 - 190 4 - 131 5 - 152 6 - 650 7 - 194 8 - 505 Now, I have no idea what these should be just yet and I admittedly didn't shoot each temp at the exact location on the header tube, but this seems way wrong to me. I would expect maybe a 50 degree difference AT MOST between cylinders, but maybe I'm wrong. At this point who knows? I have been told this is likely still a vacuum problem. So, I go back tonight with that in mind. I will trace every living thing in the truck I can think of (most all of which is already disconnected) and pray something turns up. 🙏🏻 Yes, I'd disconnect EVERYTHING associated with vacuum. You sure don't need brakes as fast as you are going and you don't the vacuum advance. Nor heater. So plug everything. Inc the line to the tranny. As for the temps, something is waaaay wrong. It looks like 3, 4, 5, & 7 aren't running anywhere near correctly. The firing order is supposed to be: 1-3-7-2-6-5-4-8. Right? So could 3 and 7 be swapped? And 4 and 7? You've said, repeatedly, that you have the order nailed, but we are grasping at straws, and that looks like a straw to me. And, have you tried squirting something like brake or carb cleaner at the intake/head gasket? It may mess up your paint job, but we are grasping, so.... Link to comment Share on other sites More sharing options...
Gsmblue Posted January 15, 2019 Share Posted January 15, 2019 Thanks for the encouragement guys. This is really becoming a battle of the will... SO after talking this thing to death with anyone and everyone I could find in addition to all the wisdom here, I thought we had it figured down to fuel delivery. AND, with the rebuilt carb being one large suspect variable I reached out and found a friend with a known good Edelbrock 500 in a box and we bolted it up and it ran like a dream! (although we didn't do the "under load" test. I thought for sure for how smooth it ran and took throttle stabs, surely it was the carb. So, I pulled the trigger and bought a new one. Here is the result: Jumping late here, sorry if this has been mentioned. But what is the fuel pressure to your 1406 carb? They don't like to be run at high pressure, I think ~4.5psi is the recommended but a stock fuel pump could be ~9psi. Again sorry if this has been mentioned already! Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 15, 2019 Share Posted January 15, 2019 Jumping late here, sorry if this has been mentioned. But what is the fuel pressure to your 1406 carb? They don't like to be run at high pressure, I think ~4.5psi is the recommended but a stock fuel pump could be ~9psi. Again sorry if this has been mentioned already! That's a really good point. Edelbrock says no more than 6 psi, so I run a regulator set at 5 1/2. Link to comment Share on other sites More sharing options...
grumpin Posted January 15, 2019 Share Posted January 15, 2019 That's a really good point. Edelbrock says no more than 6 psi, so I run a regulator set at 5 1/2. Is your carb sitting on a spacer? Like Gary mentioned use some brake cleaner to look for a leak. Link to comment Share on other sites More sharing options...
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