dkmcgowan Posted September 15, 2015 Author Share Posted September 15, 2015 Your O2 sensor should be switching every couple of seconds or less from .1 to 4.9. Thats working, how do the other numbers look in my second video? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 15, 2015 Share Posted September 15, 2015 Got a vacuum gauge? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 15, 2015 Share Posted September 15, 2015 Can't open it. Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 15, 2015 Author Share Posted September 15, 2015 Can't open it. I just uploaded it to youtube, maybe it will work there so you can see the fluctuations. Try this link https://youtu.be/9VDnASuCys0 Here are the numbers though. RPM = 590 (fluctuates from 560 - 612) O2 (V) = 0 - 4.9 (fluctuating every second) ING (mS) = 4.9 Loop Status = CLSD Exhaust = Lean/Rich (every second rotates) ST Fuel Trim = 100 (fluctuates from 90 - 110) LT Fuel Trim = 130 (doesn't move) Map SNSR (V) = 1.7 (goes up to 1.9) Map (Hg) = 12.8 Man Vac (Hg) = 16.8 (goes up to 17) Baro Pres (Hg) = 29.8 TPS (v) = 0.72 (adjusted the auto way not manual, manual would put it 0.82, tried that ran about the exact same) Throttle (%) = 14 Throttle SW = CLSD Fuel Sync = rotates between - and + Coolant (F) = 195 Charge Temp (F) = 125 Spark Adv (BTC) = 15 (rotates 13-15) Knock = 0 A/C Switch = Off A/C Request = No EGR = Off Battery = 13.9 Link to comment Share on other sites More sharing options...
cruiser54 Posted September 15, 2015 Share Posted September 15, 2015 Watched it. TPS should be at 17% and set using the flat connector. O2 switches a bit slow. Intake temp is about right. Remember it protrudes into a hot manifold. You could take it out and clean the tip..... If you rev it to 2000 RPM, you should see the knock sensor start reading some numbers. Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 15, 2015 Author Share Posted September 15, 2015 I will adjust tps tonight and play with air bleed screw, it's all the way in. What about fuel trims and other numbers, map manifold, etc..? Any other indicators of what might be causing rough low idle? Brand new o2 sensor, ntk and new relay with voltage at the sensor when car running, anything else that can cause o2 to switch slow? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 16, 2015 Share Posted September 16, 2015 LT (Long Term) fuel trim is learned over time. ST (Short Term) is what's happening NOW. 128 is middle ground. If fuel trim is above 128, the computer is adding fuel to compensate for a lean condition. If it is below 128, the computer is subtracting fuel to compensate for a rich condition. MAP and manifold are fine. Set the TPS correctly and see what happens to those numbers. Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 16, 2015 Author Share Posted September 16, 2015 I adjusted the TPS and made a new video The numbers changed slightly. I'm at a perfect 17 not on throttle position. It seemed to be idling slightly higher. I tried to increase idle with idle bleed screw, if I adjust it out, the idle goes up, then the IAC or something compensates and tries to keep it at 600 rpm. So I left it screwed all the way in like it was when I popped the cover protector off of it. When I drive it might be a little less rough now and smoother. The idle is a little lower actually when driving and at a stop light, it's down closer to the first mark, maybe 550 rpm, in drive, with foot on the brake. So adjusting TPS made it smoother but maybe idle even a little lower. I just keep reading about people having idle around 750 and that's where it should be, and it seems like that would feel great, but not sure how to get it there. Thoughts? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 16, 2015 Share Posted September 16, 2015 Back the bleed screw out a bit. Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 16, 2015 Author Share Posted September 16, 2015 Back the bleed screw out a bit. I backed it off just a little, it's the same... It might actually be idling lower and running a little rougher set at 17% as opposed to the 14% before. I'm out of ideas now... I'm going to try and track down an OEM NOS O2 sensor, and order a intake/exhaust manifold gasket and replace that. I'm considering just rebuilding the head or at least having it checked out while I have intake and exhaust manifold off. I also considered a last ditch use of seafoam to see if something is clogged or not seating. Link to comment Share on other sites More sharing options...
cruiser54 Posted September 16, 2015 Share Posted September 16, 2015 Okay. Slow down. Vacuum gauge test. BG44K in the fuel tank. Original injectors? I don't remember. Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 16, 2015 Author Share Posted September 16, 2015 Okay. Slow down. Vacuum gauge test. BG44K in the fuel tank. Original injectors? I don't remember. I did the vacuum gauge test, it seemed fine, I posted a video earlier, will try to find it and get it on you tube as well. It was around 17 hg, took it to 2k rpms, let it settle and it seemed to do what it was supposed to. I ran some bg44k through the system, then went ahead and got new cleaned up 746 injectors. I adjusted idle screw in half turn increments, all the way to 4 turns or almost all the way out. The IAC adjusts for it and idle still rough. I did pull the ccv off the manifold, let it just suck in air then my idle goes up to maybe 750-800. It runs so much better in open loop when you first start it for those few seconds. I was thinking about messing with butterfly stop to see if I could raise idle temporarily since idle bleed doesnt, I know I shouldnt. Not sure what the signs are telling us. Link to comment Share on other sites More sharing options...
cruiser54 Posted September 16, 2015 Share Posted September 16, 2015 At idle, is the needle on the vacuum gauge steady? Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 16, 2015 Author Share Posted September 16, 2015 At idle, is the needle on the vacuum gauge steady? here you go, what do you think? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 16, 2015 Share Posted September 16, 2015 Hold it at 2000 steady and let the gauge stabilize. That reading should be the same as it was at idle. Let the throttle snap shut and observe the gauge. Your idle isn't all that bad. What happened to ST fuel trims as you turned the air bleed? Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 17, 2015 Author Share Posted September 17, 2015 I will try that later tonight if I can get the wife to hold the pedal while I film, otherwise I will get her to help tomorrow. The idle really isn't that bad and never feels like it's going to die, maybe my car likes to idle at 600 rpm and that's fine. Maybe I've been tracking the wrong issue. Let's reset and help me with this description of the issue. What would cause the vehicle, when warmed up, at idle, to have a slight miss or stumble? Not that bad, but you can feel it, and at times it can make it when your holding the steering wheel you can feel the vibrations. This stumble is not really there at all when the vehicle is cold and in open loop. The stumble is not there during accleration or at higher RPM's at all. There is no hesitation or lack of power at all. It also stumbles less with a bad o2 sensor when warm, one that is stuck in open loop, so running rich, which you can smell, but it's stumbling less. I have proper indexing on distributor, new cap, new rotor, proper gap on new ntk plugs, new wires, cleaned all electrical connections, all new relays on the passenger side, cleaned ignition coil connections, and fuel pressure seems good, about 3 psi low, but that could be the gauge. should I try a new ignition coil? Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 17, 2015 Author Share Posted September 17, 2015 I actually just got it to run pretty good. I decided to adjust the butterfly stop. When I first got the Comanche, it was pretty open. So I adjusted it pretty much all the way closed, I used my gap, and I got it to where there was resistance pulling out a .0015 gap. I just now adjusted it two more sizes up, so there is resistance pulling out a .003 gap now. It's the 3rd smallest on my gap tool. It's still like the size of a piece of paper, super small. I kept adjusting it, and fixing the the TPS to keep it at 17%, until I saw my ST fuel trim get close and stay around 128. With the little bit of extra air, the o2 seems to be switching faster between rich and lean, the idle in park is about 800 rpm and more steady, and the idle in drive is over 700 RPM and really steady, needle not moving at all, right on the second line. The miss is pretty much completely gone and the idle feels pretty smooth. I plan to drive tomorrow and see for sure. Not sure why the adjustment wasn't working on my air bleed, it should have accomplished the same thing and is the correct way to fine tune, it's still all the way closed, maybe it's clogged or something? It just needed some air. I'm feeling pretty good, will see for sure tomorrow in a real world drive. This still might mean something else is wrong, but it feels much better. Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 17, 2015 Author Share Posted September 17, 2015 When I said gap I meant feeler gauge Link to comment Share on other sites More sharing options...
cruiser54 Posted September 17, 2015 Share Posted September 17, 2015 Wow!!! I'm curious about how you used the feeler gauge. Perhaps we could glean a real-life spec for the throttle body out of this? Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 17, 2015 Author Share Posted September 17, 2015 Wow!!! I'm curious about how you used the feeler gauge. Perhaps we could glean a real-life spec for the throttle body out of this? I will make a video tonight and post it later... Link to comment Share on other sites More sharing options...
cruiser54 Posted September 18, 2015 Share Posted September 18, 2015 Wow!!! I'm curious about how you used the feeler gauge. Perhaps we could glean a real-life spec for the throttle body out of this? I will make a video tonight and post it later... We could put your name in lights!!!!!! Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 18, 2015 Author Share Posted September 18, 2015 So here is a video of what I have been doing to set the throttle stop and keep trying to adjust it. Right now it's at .005 with my feeler gauge. I also set the air bleed 1 full turn out, so I could have it as a future adjustment. When I adjust the air bleed screw, it now works and makes a difference. I'm not sure I have it setup right. The car runs best, if I can get idle to 700 rpm, in drive. When I do this, the idle in park is like 860-880, which isn't that bad. With an IAC is there still supposed to be a difference between park and drive or should it go up when you put it in park and the IAC should bring it back down? Also, now when I turn on the AC, the idle drops a little, not bad, but before it would raise the idle, like the IAC would kick in and raise the idle up when it detected the AC, now it drops, does it the idle going down with AC sound normal? The idle still shoots up when I crank the car, so I know the IAC can rev it if it wanted too. Here is the video, you will see my ST fuel trim when up as well as the o2 sensor doesn't show going all the way to 0.xx as much, maybe it's going faster? thoughts? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 18, 2015 Share Posted September 18, 2015 Nice video. Idle is a bit high. Can you drop the idle with the bleed screw 100 RPM now? What is the "sync" reading? Link to comment Share on other sites More sharing options...
dkmcgowan Posted September 21, 2015 Author Share Posted September 21, 2015 I think the correct number for the throttle butterfly is .003 - .004. I had a friend measure two Comanches he has and both were around .003. I set mine to .004 because it ran better there. I also have the air bleed all the way clockwise, both the other Comanches were this way. This can be used for some adjustments later. I go it so that the .003 will slide in and move easily back and forth, the .004 will slide in but it's difficult and it will move, but it's pretty tight. The .005 will not fit at all. So I imagine it's probably around .0035 give or take. This should be a good starting point. This puts my idle in 650 rpm in drive and around 750 in park. Do other peoples idle change between park and drive? Link to comment Share on other sites More sharing options...
cruiser54 Posted September 21, 2015 Share Posted September 21, 2015 Yes, our idles change. Link to comment Share on other sites More sharing options...
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