Palmettobug

So UPDATE : I purchased a reconditioned set of carbs from ZTherapy. Smartest thing I could have done. These things look amazing! We bolted them on. Made sure the mixture nuts on the bottom were turned 2 and 1/2 turns down, started first time. I have since had the car on the road and its drive able. Needs new springs and shocks. But the new carbs have sure made the biggest improvement to date.

Re-reading this thread, I decided to pull the plugs. From left to right, its #6 to #1. 4-6 are a little black, not much. 1-3 are whitish-tan. Cleaned them up, put them back. Re-dialed the mixture. Fixed the fuel pumping leak in the rear carb. Not a clue how I did it. I pulled the float out, wiped it down. Made sure the needle opened and closed. Cleaned the tan/brown varnish stuff off the bottom of the bowl. Car idles at 1200. Drops to 500 when placed in drive. And ..... we're back to hesitation/sputtering under acceleration load, and can't make it up an incline in the neighborhood. WTF??? I was having a blast flying down the road earlier. What the heck went wrong?

OK, so today I go buy a fuel pressure tester. It won't hook up to a Nissan. Domestic fittings. In the mean time I decided to pulled the fuel hose off the fuel rail to see if the pump would work. Started with the back carb, turned ignition key to accessory, and Beautiful! We got gas coming out the fuel rail to the rear carb. Did the same thing to the front carb. Same results. So I'm thinking the fuel pump isn't the problem. It's idling at about 1300 rmps. I decide to see if it could make it up small hills today. I go driving around the neighborhood, no problems like before. No sputter, no hesitation, Figure why not go down the road where there's huge hills. Made everyone with a loss of power. OK, let's see how fast this thing will go. Hit the highway and got it to a 100. While it did build up to it, there wasn't an immediately response from the throttle, it's still 10 times better than it was last week. No idea what I did to get it here. However, when I get to a parking lot to check under the hood for problems; I have fuel coming out the air intake hose and front of the rear carb. It's squirting like its being pumped from the fuel pump. How the heck to fix this new problem?

I did put in new plugs and cleaned the carbs. But you're right, I haven't even thought about the distributor. Maybe it is time to put new points in. I'll check on that. Thanks ! I'll check on the fuel pressure too. I did do the "there's plenty of fuel in the filter" test.

S30Driver : Nice to meet you. Has Zup ever had the acceleration problem I seem to be having?

I've got what I think are '72 SU carbs. You can see them in the above pictures. They have the large screws instead of the flat screws. I turned the large screws all the way up and the backed them down two-and-one-half turns.

I could use new friends that lived closer. You guys are on the coast and I'm stuck here in the middle. Haven't seen anyone from Tulsa on here. Anyway, last couple of days I have sync the carbs with airflow. I think I got the fuel mixture right. I have the idle dialed in at 1000 rpm in park, 1200 rpm in drive. I make it out the driveway and step on the gas ..... I get jerking and hesitation. The carbs backfire, and the rpms drop to 500 and stall out. I recrank and put the choke on. I can make it around the neighborhood. Haven't been adventurous enough to jump on the highway. Think I may contact a different shop this time. The alternator thing I was saying because the headlights run dim. Most of the threads I've read say I should upgrade to the 60 amp and purchase the headlight harness from Dave. I also need the Honda upgrade swap for the windshield wiper motor and the heater blower motor. All of which can wait until after I deal with the carb issue.

Dang it. Well, there's another mod I need.

So I believe this is the regulator you were referring to..... And this is a picture of the alternator.... I see an E on it. Don't see the S or L you talk about. Not sure if this is a 40 or 60 amp.

The manual doesn't say where the voltage regulator is located. I assumed it would be on the passenger's side , close to the alternator. But could you put one of those cool pictures up? I do much better with those.

Yeah I think I'm going to have to call them for the video. Getting somewhat discouraged.

That was going to be a question of mine a little further down the line. How do I tell by looking if someone swapped the alternator? Thought everything was synched right in the driveway. Tried to pick the kid up from school and the car died under accelerator load. Spent 30 minutes screwing with the carb adjusts to get enough power to make home. Stopped by Advanced Auto. Guy says he turned the front 1 and a 1/2 turns before it affected the rpm's, the rear one he turned 3/4 of a turn before affect on rpms. He said the front carb needs to go in for rebuild so you might as well do both. Sound plausible? And we haven't even gotten to suspension problems/questions yet.

My engine bay is not as great as your friend's, but I'm trying. I though the mechanical fuel pump was this little blue motor thing right behind the first carb. Whatever it is, it has two wires that have female connectors which aren't connected to anything. There is a small hose that comes out of it on the right side that is plugged. I think think pictures shows the mechanical fuel pump..... The small silver circular thing with the blue collar around it by sparkplug #1. Since that's where the fuel line runs... BTW, while pulling lightly on the sparkplug wires to make sure they were all seated correctly, I also pulled on the fuel hose that runs into that mechanical fuel pump. I don't think it's suppose to split off in your hand...... I had to run into town and get a new hose as it appears the fuel ate into the delivery hose. Problems possibly caused by air leaking into the fuel line??? I have since adjusted and synched the carbs (again). The air flow on both appear to be 9.5 back and front. Adjusting the mixture is a pain as I have big knobs on the bottom of the carbs instead of flat nuts like most directions refer to. My tach is adjusted to 900 at idle.

How do I post a photo? Having a memory problem here.

Siteunseen: I did go buy the Fram G2 filter like you suggested. Must easier to see into than the plastic. There was plenty of gas in the one I removed. At least I know the electrical pump is working. The hesitation thing seems to be intermittent. I've been up and down that hill I described at least five times, only had a problem once. Not sure what that means.

Siteunseen: There is a mechanical fuel pump still mounted above the first carb, but the wires aren't connected and the hose is plugged off. I just replaced the spark plugs yesterday. The first three appeared to be white. The second three appeared more blackish. I adjusted the fuel mixture after changing the plugs. Which was before I experienced the loss of power. I am running Seafoam through the system now. And its the second time I have experienced this. The first time was why I looked up the threads and started changing plugs.

I have a '73 240z with automatic transmission and original L24 engine. I put it in the shop as soon as I bought it, as it needed all new brake line and master brake cylinder. I also had them put in a new flexplate, as mine was missing quite a few teeth. Add a new started. When I got the car back, I pulled the SU carbs off ( the PO said they were off a '72) and cleaned them. Placed 3-in-1 oil in the dampers, replaced spark plugs with NGK 6ES. Adjusted carbs with a flow meter and adjusted the mixture screws. Even put in a new in-line fuel filter under the hood. I turn the engine with the choke on and let it run at 1500rpms for a few minutes before taking off. It usually idles at 800-1000 while in park, 750 in drive. I for twenty minutes and the temp gauge shows halfway (200 degrees??). I can get it to 4000 rpm's at 90 mph. Then a few minutes later it starts jumping/studdering while going down the highway. If I go up a small graded hill, the rpm's drop and the speed drops to 50 mph. Once I get back on level ground, I can get the car back up to 75mph. I believe the PO put in an electronic fuel pump near the gas tank. I notice it "ticks" when I turn the accessory power on before fully starting. I've read quite a few other threads on this, but they don't seem to address quiet the same problem I am experiencing. This is my first Z, so I have all kinds of other stupid questions once we figure this one out.

Thanks DJ. Talking with the maintenance guy about whether we need a flexplate. Priority is on fixing these lousy brakes. Having to put new wheel cylinders on and replace all the copper tubing. Seems the bolt heads got stripped the last time someone changed the brake fluid. Hopefully will get everything fixed after the holidays.

Thank you everyone. Hey, Siteunseen; thank you for checking. Hope you can find those parts. Still working on the brakes over here. Found the rear wheel cylinders in the rear were leaking and needed replacing. Replaced both front calipers in the front last weekend. Not sure about what fluid to use. Dot 3 doesn't seem to give much braking power. I drained some kind of greenish fluid out. Is that Dot 4 or 5?