mec011

I had a similar problem that ended up being one sticky float valve. Cool motor and/or low RPMS was fine, but you'd get down the road a few miles, build up some heat, and it wouldn't go beyond 3500 RPM, and it struggled to get there. I went through the same spark and fuel filter checks. Once I pulled them out, it was clear that one of the valves was not particularly free, and must have only got worse when hot. Maybe something worth checking if you've not already.

Well, I don't have a fuel flow meter, the auto parts store said they didn't have one either, can you point me towards what I'm needing on the net or something? Also, no sort of insulating tape either so I'll have to look another place. I do have a engine vac/fuel pump pressure gauge. I used a T fitting and put it in the fuel line in several spots. Between the filter and the pump in 5/16 line, it seems to show no positive or negative reading, but the needle jumps and pulses around. At the rear carb inlet in 1/4 line, it's showing a solid 3 PSI. At the end of the 3/16 return line next to the pump it's showing .5-.9 PSI with a bit of pulse Don't know how these numbers sound to you guys? But again, the car held a nice tune until it started getting really warm, then it seemed to be running very lean, even with 3 turns of the idle mix nob, based on the fact that the flow gauge or my hand would make it quickly run right as I covered the mouths of the carbs. I would also get some back firing as I revved the motor up. If the fuel pressure sounds good, maybe it's a float issue? Some choke still seems to be smoothing the car out a bit, which still makes me think it's very lean. I'm a bit befuddle! It seems really odd that it will run good for 5 minutes (after warming up with choke for 5 or so) then start running like crap. Thanks again for any help!

One thing I thought of, what should I torque the PCV to? It's in good, but not really torqued down hard, maybe 10 ft/lbs?

The heat shield is on for sure, and I imagine doing it's job because of that? The thing about the choke, the light will not go off, but I've checked that it's got full range of motion on the carbs, it just seems that there is always a bit of tension on the handle, but it's not moving the actual linkage, I've gone as far as to remove and reattach the choke cables to kill the light, but no luck on that end so I'm not really sure what to do about that. But I'm sure it's not keeping it choked, I checked the operation while I had the domes and pistons off, it returns to normal just right. The fuel lines are the standard metal ones, they run along the valve cover, with a rubber tubes to each carb, then back along the cover to rubber lines between the fuel pump and fender then metal tubes along the passenger frame rail. Where would you suggest insulating them (along the valve cover I'm guessing?) and what would you use to do so? I'll check the return fuel flow. Is there any sort of filter or servicing that the mechanical fuel pump needs? Thanks for the advice!

So I'm having some issues with my 1972 240z. When I bought the car, it was running but really down on power. I went ahead and did the basic maintenance work on it, I installed a Crane XR700 optical points system, a Crane coil, new plugs, spark plug wires, rotor, and distributor cap. Checked the timing, and I have good compression, 145-155 across the board. Initially it still felt down on power after all of that, better, but not great, then I found some bad connections at the ballast thanks to jiggling the right wire at the wrong time. Cleaned up the electrical connections around the ballast and coil, and I had power! The car then would run great if you started it cold, and drove it from that point. If I stopped, like to go into a store, 5-10 minutes, it would have trouble starting, but would with a bit of gas as it started to catch. However at that point, the car would not run right. It still had power at low RPMs but it stumbled after about 2500 rpm when you gave it any throttle. It seemed to smooth out some with the choke on, so that led me to believe that maybe it was having some sort of fuel issue. Interestingly, it seemed to still run fine if it got cold again, or if it sat for an hour or so before being restarted. At this point I may have messed up, but I watched the Ztherapy SU video, and went ahead and cleaned the domes and piston, used ATF fluid for the pistons, reset the mixture and needles as was described, started the mixture at 2.5 turns down, and then attempted to tune the car. I let it get warm, temp gauge up to operating temp, and adjusted the mixture, 2 turns was the right spot it seemed (I'm running an SM needle that the previous owner said runs rich). I had just a slight flow imbalance that I fixed with a tiny turn of the rear carb idle screw. The car was running good at around 1000 RPM Idle. I went to do the High Speed balance adjustment, and the car started to get worse and worse. I didn't get the balance done because I couldn't get my flow meter to read at the high RPM, but when I backed it off of 3000 RPM it was running terrible again, worse than ever before really. It was sputtering badly, and seemed to be running very lean, (Hand over the carb opening would make it run smooth briefly) and I'm almost thinking I heard a vacuum leak, but it could just be the carbs sucking a ton of air. All my vacuum tubes look good, and I couldn't pinpoint the sound, but it was not there when I started tuning it, or before that I remember, which makes me think it may just be the poor running condition. One thing that seems odd to me, is that the fuel filter on the fender, seems not to stay full. While running it seems about a quarter full at best. The other day it was full up for a while. Based on that, maybe I'm not getting fuel, but I'm not sure how the filter is supposed to look. I'm a bit out of ideas at this point, any help would be greatly appreciated! Also, the mods to this car are the Crane XR700 which I put in just recently (I never had the car running right before that, I put it in as part of the tune up) and it has a Stage 1 Crane Cam per the previous owner, if that makes a lot of tuning difference.

Thanks guys! Picked up a 1515 from Napa yesterday, under $7 here, 1521 is just the same but smaller capacity according to the store. Looks like oil change fun tonight!

I've got a quick question, I'm ordering parts to change my oil on my newly acquired mostly stock 72 Z. I'm going with the Valvoline VR-1 10W-30, and I'm partial to Wix/Napa Gold filters, but the part number given for the 240Z is 51521 (Napa 1521), and my Z currently is running a Fram PH8A which is equivalent to Wix 51515 (Napa 1515)*. The difference looks to be only the capacity, any opinions or experience as to which one to go with? Thanks! *Edited to fix my own part number error

Thanks all the info Bigoak! The big issue with the 72 in charlotte is no title right now, it looks good, I emailed him about the possibility of getting a duplicate, but you pretty much have to have the title, the laws just changed this year and are very strict about classic cars now, but i'll run it down. Also, on the 280Z I went and looked at, the (tiny) holes in the floor pan are a bit odd, they seem solid, there really is no rust, just two pinholes, one in each floor, so go figure?? I should have taken more pics!

This may be my first post, but I've been lurking for a while, soaking up all the info I can! I'm considering purchasing a 1978 280z. I'm really looking for a car I can drive and enjoy, I have a 2004 350Z that's my daily driver, and I've gotten the bug for an older one to have fun on the weekends with. The price will be a bit under $3000, and it needs tires, and a muffler, (and brake work, which I can do). which sounds reasonable to me, but maybe not to any of you?? Here are some of the flaws, etc I noticed when I went down to look at it. -It runs good, no smoke, hesitations, etc, and the 5 speed shifts firmly with no grinds or anything. It drives very well, but needs one rear brake worked on, the seller claims it's leaking down over time, and to that end, the red "BRAKE" light flickers on and off as you drive, the master cylinder is full, which is usually what causes the flickering light on every other car I've had. It also seems to not have power steering, which I believe is correct for a 280z? -The interior is okay, both seats have small cracks, etc, no carpet in the drivers section, but there is in the rear hatch. The dash is cracked. All the gauges seem to work with no trouble. It present well inside, other than the few flaws I mentioned. It supposedly has A/C, doesn't work, but the blower does. -The exterior is alright, the paint is black pearl, has the 638 paint code sticker but I don't believe it is the SAP, no stripes, one (wrong) mirror. Seller claims its the original paint, which I kinda believe, it's cracked and spiderwebed, a real 20 foot paint job The good thing about the car is it's overall rust free. The seller claims it's been garaged most of it's life. The underside looks really solid as well as the doglegs and rockers. There is a bit of bubbling on the lower quarter panel next to the muffler. The floor boards, driver and passenger, both have one icepick sized whole, but look solid otherwise. The only big issue is the battery tray area. Seller claims it was recent, from, go figure, a leaking battery. I've taken some photos, and advice on how bad it looks would be appreciated. It seems to be just surface rust right now, the rails seem to be solid from tapping on them. But this is the only one I've seen, so...? Any comments would be appreciated! Also, I suppose I should ask, I'm looking, total initial budget, at maybe $3500, max, to have a drivable, if cosmetically poor, car on the road. I'd consider any 240Z, 260Z, 280Z, but I am partial to the 240Z, simple for the "original Z" factor, however I'm not buying one to collect, just to drive and experience and enjoy, so I wont be disappointed in a 280Z, but it seems as if getting into a rust free driver 240Z is going to exceed that budget, at least on the East Coast? But maybe I'm wrong? Hope fully this is a realistic starting price to get into any classic Z at all? Thanks!