Mudge Posted January 22, 2003 Share Posted January 22, 2003 Originally posted by Tomahawk Z:Mudge.. $1400.00 to fix Weber jets? Tim 240 Z paid $700.00 to fix his Weber jets and got a complete ZXT car. Hey Tim.. is the zxt painted yet? Yes, meaning I'm not going to go buy a tripple setup already ready to go, I would rather go EFI which yes, a donor car would do quite nicely, but I'd rather have a Megasquirt. If I'd go EFI I want to play with it, not expect an EFI system for 150 HP engine to run a 250 HP setup in the future. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 22, 2003 Share Posted January 22, 2003 I wanna ZXT like Tim's........I knew that you would have that car mrchanically ironed out over the weekend plus a few cosmetic chores accomplished.! and with Midge on the Weber jetting for the other driver, you can just retain the ZXT until V8 time. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 22, 2003 Share Posted January 22, 2003 Turbo would be great, as a road car though I'd have to battle heat, so eventually I am PROBABLY sticking with a completely NA F54/N42 setup, I'll miss some TQ and HP, but heat wont be as much an issue. Ok, I have found some places that DO sell a conversion kit for 32/36 on the Z, but figured if you dont buy the setup they probably wont tell you the jettings. I am going to get some help from a Pierce Manifolds guy (Morgan Hill), who does sell the conversion setup. So, I'll tear open my carb and write down everything thats in there to figure out about how far off I am. I will found out either later today, or will post results tomorow. They dont exactly have a store front but I can pickup items at the front desk/willcall, or of course you can order online. http://www.piercemanifolds.com/products.htm Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 23, 2003 Share Posted January 23, 2003 Ok, got home, worked as fast as I could without breaking things, and it looks like I wont get help today. I did however verify, that I indeed have stock settings in this carb, which means 3.2L worth of fuel on a 2.4L engine, no wonder 15-16 MPG is the best I can nail down. I also have a Redline Weber tag, and its got a CARB EO on it, if any of you have the same? CARBURETOR REDLINE-WEBER 32/36DGV5A K8688 CARB E.O. NO. D133-3 Quote Link to comment Share on other sites More sharing options...
Tim240z Posted January 23, 2003 Author Share Posted January 23, 2003 Mudge, WOW, I have that exact same tag. I pulled mine off of a JY 260Z about 8 months ago. I would be interested to see if your jets are the same as mine. BTW, in an attempt to richen up the primaries, I swapped the secondary jets for the primary fuel air jets. I drive mostly on the primaries, so I wasn't too worried about the secondaries being too lean. Tim Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 23, 2003 Share Posted January 23, 2003 Since it says REDLINE WEBER it tells me it was setup for a converted car, but that sure is alot of fuel for such a car, which is wierd. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 23, 2003 Share Posted January 23, 2003 Ok, not sure on gas mileage yet but here is my story. After talking to the tech guy at Pierce Manifolds for awhile, he actually determined that I was lean at idle. I didn't understand this at all until finally meeting with him and him showing me how it works. My idle screw had to be at least about 2.5 turns out in order to get the car to idle when warm, without the choke, so he said 3/4-1 turn only. I thought I had seen that 2 turns was ok somewhere but that may be another carb, or misinformation. Anyhow, so I bought several jets for the idle screw side and the other side. The one near the idle screw he said is the most important, sometimes going beefy here will also get rid of or help transition from normal driving to WOT. I found that I had 50 on both sides, unlike the 55/50 listed for the Euro-Ford setup, but everything else was spot on. Anyhow, I started with a 65/60, 65 being at the idle screw spot. This helped but I was still barely idling with 1.5 turns out. Made sure the car was warmed up by driving around a bit. Went back after that to pickup a set of larger jets, this time 75/70. I only put the 75s in and had the idle screw out 1 turn to see if it would work. Was not very cooperative, so I turned it out another half turn to 1.5 turns and it idles fine without the choke. Maybe if I try backing the idle down it will help stabalize with less turns out, I dont know yet. So basically what happens is, thanks to his explanation, when you have to overcompensate with the idle screw to get the car to idle steadily, this will work for low velocity/vacuum which is your idle situation. When you are off idle however, more velocity and vacuum will run you RICH, this explains the 15 MPG I was seeing. I was overcompensating for a lean idle and screwing up the rest of the circuit. Driving back from Morgan Hill was about 70 miles, and the tank looks good for now but I wont know for sure about the MPG for a day or two. Once I can figure out some more stuff I will probably order more jets and maybe other parts, but this is the basic situation, check how many turns out you are. I really didn't know it was that important, and that is where talking to someone in person who knows what they are doing, really helps. Oh, I also noticed that I didn't smell the gas fumes like I did before, so I rolled down my windows more to kind of make sure, and there is nary but a hint of fumes! The guy I spoke to was Doug, young guy but knows his stuff and was very helpfull. Thanks again Doug! Customer service was top notch as well as Doug's help, I dont know the gals name that was there but they definately run an A+ organization. (so at current I'm running 75/60 not 75/70, I may put in the others later today). Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 25, 2003 Share Posted January 25, 2003 Mudge - When you said your jetting are stock, "...that I indeed have stock settings in this carb", I assume you mean what is listed on this web page http://www.efn.org/~msayer/weboem.html correct? Looks like you found out some pretty good info. Although the way I understood these carbs to work was that the idle circuit affected just that, only idle. Once you were past idle, these jets didn't matter. Therefore, they couldn't make you run rich during driving conditions. Just what I've read, wondered if maybe you posed the question to him. I guess your MPG might tell the answer to this question. I need to break into my carbs and figure out what my jets are. Let us know how it works out. Later, Chad Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 25, 2003 Share Posted January 25, 2003 Actually, the idle circuit is the PRIMARY circuit, meaning all low RPM stuff. There are two parts to the idle circuit (if not more depending how you want to look at it). Anywho, not what I expected but when he explained it it all made sense. So far the MPG looks good but I haven't been driving much, been working all day long just about the last two days working on the suspension, tomorow at 5AM I get to wake up for Sears Point (5.5 hours from now). I had to do the rear springs twice, because the stockers I put on there must have been front springs, they were WAY soft, so I put back what was on there in the first place. At least I didn't have to remove the brake lines the second time around. I didn't follow the instructions either, they want you to remove a bunch of stuff, I just pushed hard on the spring seat and pushed the sucker in. Anywho, my carb was "stock" in terms of the Ford yes, OTHER than I had 50/50 idle jetting not 55/50. I was out over 2.5 turns to get it to idle ok. Remember that this idle circuit apperantly affects the rest of your under 3k or whatever (secondaries are vacuum), and if open excessively it will throw tons of gas into the car since its open more than it should be, vacuum sucks more of it in than needed. I'm very tired, so hopefully whatever I said above makes sense. So, if you have the Weber downdrafts and you are getting crap gas mileage, follow the instructions for BEST LEAN IDLE, its in the Weber books and online also. If you are way past the recommended number of turns, then you are in the same boat I was in and you need to RICHEN at least the jet on the idle richness screw side, the other side is not so important for solving the issue. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 26, 2003 Share Posted January 26, 2003 http://www.theape.com/jets.html The idle jet provides fuel for the idle and progression circuits. The size of the fuel orifice affects the entire operating range of the idle and progression circuit. Lean best idle procedure: http://www.redlineweber.com/html/Tech/carburetor_set_up_and_lean_best_.htm Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 26, 2003 Share Posted January 26, 2003 (this was supposed to be a test post, forgot I can't del my own stuff, doh) Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 28, 2003 Share Posted January 28, 2003 Looking good, I'm definately in the 20s, I should know in 2-3 days what my MPG is. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 29, 2003 Share Posted January 29, 2003 Have you noticed any improvement going from partial throttle to wide-open? Have you looked at your plugs since doing this? What did they look like prior to? Always Carbon-fouled? Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 29, 2003 Share Posted January 29, 2003 Not hugely carboned, but some yes. I haven't checked plugs since then. I have no balance tube, and I only just today received my carb synchrometer, thanks to a backorder. I want to say that I'm getting exactly 20 MPG right now, but I want to go get gas and make sure, because the gas gauge is not 100% linear. I am pretty sure its 20 even though. This includes SOME WOT stuff but not a ton, and I might be in the secondaries on the freeway I'm not sure, because I dont know the vacuum numbers on this. I cruise at 3400 about on the freeway unless I dip under 70. I want to play with the jets more though. It is also possible to get poor MPG from: Worn throttle shaft (vacuum leak I guess) Dirty emulsion tubes Plain old clogged jets I dont imagine the lack of a balance tube is helping, and I have no idea how out of synch these things can be. Exaust odor was way down, almost not there, that is what I noticed more than anything I could say about part throttle driving. It may seem better but not enough that I really took note of it. Also, I have a 75/60 setup, probably not optimal but I need an overview of the left/right side of the idle circuits to figure things out which I will study tonight after the gym/gas trip, and then try to tune them tomorow hopefully. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 29, 2003 Share Posted January 29, 2003 Well, about 19.4 MPG, definately not steller but I half assed it by doing the jets like I did. I am going to get a tube across both carbs and try to read up on the idle circuit some more, and then throw some other jets in there since I have 60/65/70/75 to choose from. I also heard that something as simple as a rebuild kit sometimes helps. I'll report back when I have something worthwhile. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 29, 2003 Share Posted January 29, 2003 Today I'm running 65/60, and as soon as I put the 'balance tube' in place RPM picked up about 300-400 or so, a huge jump. By the time the car was fully warmed up, with the choke off, my car was idling at 1800 RPM, yes 1800. In other words, whoever lost the T fitting did themselves and me a disservice MPG wise it looks like. I dont have the carbs balanced yet but I have idle readjusted to about 850ish or so when I got to work, and it looks like a 75 is definately not needed. 65 in the idle screw side, and 60 on the other. I'll see how it goes and maybe lean it out further from there. I made zero adjustment to the idle screw, it is still 1.5 turns out. It also seems to have more power with less throttle input. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 29, 2003 Share Posted January 29, 2003 Mudge...outstanding progress on adjusting the dual downdraft Webers. One of the complaints that I always heard is they could be impossible to tune but properly done a great set up. I ran single down drafts on the L 20 B's and once found the engine would idle even after the top horn cover plate was removed. The only way to fix a OEM Datsun carb is with a Weber. Quote Link to comment Share on other sites More sharing options...
Mudge Posted January 29, 2003 Share Posted January 29, 2003 Thanks Tomahawk, if anything its almost embarrasing that its taking so long, but its not a huge thorn in my side so I guess I'm being lazy about it. Things like not having a balance tube, definately not cool, but I can still only guess what it does (I assume its vacuum balance). They are supposed to be tuneable for great MPG and I want to believe that, they are kind of like a Rochester QJet which had the same reputation, both being progressive carbs with a small primary and juicy secondaries, other than that there is almost nothing that I know about Carbs so the learning curve is stiff, and I will say the books are not helping because I need THEORY, not just information on how to dissasemble them. Looking for anything in terms of re-tuning a carb, other than the idle circuit with NO theory behind it, seems to be a waste of time unless you have a side draft in which case everyone and thier grandma has one or wants one. So, I think I'm on the way to figuring things out and looking forward to mid 20s? Maybe better?... Quote Link to comment Share on other sites More sharing options...
Mudge Posted February 2, 2003 Share Posted February 2, 2003 Still playing with the carbs, today I took a look at noticed that the links were not the same length on the same side, they were off by about a centimeter, which is alot. So I started to fix that, and then the car wants to idle at 2500 RPM, fabulous Then I see why, the pivot point which attaches to the link is at an angle on one side, whoever put this together I have each carb pulling about the same amount of vacuum and am back to 50/50 jets, BUT the idle wanders up and down so I am just about fed up with carbs, damn I hate these things. So, nothing fabulous to report, just a bunch of stuff pissing me off Clearly I need an exaust gas analyzer or a color-tune. From there I'm guessing that the solution might be a 60 in the idle side which worked fine, and a 35-40 in the secondary idle side, but until that point, its all guesswork which is not very fruitfull. Quote Link to comment Share on other sites More sharing options...
Mudge Posted February 4, 2003 Share Posted February 4, 2003 I think it was a mistake to ignore the main jets, after going through the book again and re-reading web stuff. Whats that saying, stupid is as stupid does? So, once I re-fix my idle, I'm going to work on the mains as my excuse for the remainder of the RPM. Quote Link to comment Share on other sites More sharing options...
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