How to get 260Z to daily driver status?

[Captain Obvious]

Your cold start and running issues don't surprise me at all:

"In 08/11/08 it had all the hoses replaced, repaired the choke and cleaned out the carbs and had 83,520. I bought it with 83,760 on Friday."

Sounds to me like the previous owner was chasing a performance problem with the car... He had all the hoses replaced and the carbs taken apart and cleaned out four years ago, and then put less than 250 miles on it since. I assume it's been sitting with the same gas in it for those four years? I'd be happy that it runs at all!

If you're looking for significantly better performance that what you're getting now, you're probably going to have to get inside the carbs. Or open your wallet and find someone near you who's got a handle on the infamous flat tops and hope that it's something simple that can be addressed by the anemic rebuild kits. If you were closer to me, I'd be happy to help you with them, but I'm several hours from you.

Also, from one of your previous posts, there's a question that hasn't been addressed:

About the diesel noise, Ive narrowed it down to this area:

[ATTACH=CONFIG]55738[/ATTACH]

What is that covered by that cap?

Under that cap is your EGR valve.

I'll second the guess that you've got an exhaust leak. Probably at the rear of the engine back by the firewall.

[Captain Obvious]

Speaking of EGR, one of the things that can cause the problems you're describing is if your EGR valve is active when it shouldn't be.

The EGR valve should only be open after the engine has warmed up, and if it opens before that, it can cause rough running.

To check for that, pull and cap the hose running to the EGR valve (the thing with the large round cap) and see what happens.

[porkbun]

In 08, the car wasnt starting, the alternator wasnt charging, and all the fuel lines were replaced at Acme Nissan in NJ, so it sounds to me like they were trouble shooting and happened to notice the state of the fuel lines. According to the receipts, it seems that it was a daily driver until the 80s (70k in 83)and then the mileage per receipt interval starts dropping down to a couple hundred in the 00s. I have no problem with the performance, but sometimes in first, ill experience a bit of a hiccup under heavy acceleration like the car is just realizing how hard im pressing down on the gas (like an automatic transmission changing to a lower gear for more power. carb lag?). I also feel like I could be getting better MPG since I do mostly highway driving, but I do enjoy the acceleration in town.

I would like do work on the carbs, but it all seems to be a bit over my head. Would just replacing them with the 240 SUs or another carb make maintenance easier? I havent called around yet, but I feel like getting different carbs would be cheaper than always having to rely on someone else to take hours to get everything right.

This is the clacking diesel noise I hear when I start the car and the hood is up, but its definitely coming from the area in the photo. I havent even noticed it anymore because I can hear it in nearly every other engine bay video (or its could be stuck now that I think about it)so it doesnt really seem like a problem to me:

. Ill try covering up the EGR tomorrow to see what happens

[Reverend]

It would totally make maintenance easier, there is tons of info about round top SU's here and they are most reliable carburators i have ever stumbled across. I had them tuned by a pro and i havent touched them since (2 years). There is good quality sets for sale if you keep looking, im sure many of our forum members have extra pairs waiting for someone to buy them

[Captain Obvious]

Problem is that you've got no "baseline". You don't have any portion of the car verified, tested, proved positive, that you can be completely confident is working as designed. What I mean by that is, for example...

sometimes in first, ill experience a bit of a hiccup under heavy acceleration like the car is just realizing how hard im pressing down on the gas (like an automatic transmission changing to a lower gear for more power. carb lag?).

Stuff like a short lived dead spot, "bogging" on heavy acceleration as you described above could be caused by a whole bunch of things. Some carb related, some not. Could be anything from lack of oil in the carb dampers, to a clogged fuel filter back in the electric pump, to a distributer problem. Might be fuel related, might be ignition related, might be air related. Could be anything. Point is, either you better get good at opening your wallet, or you better get good at finding and fixing your own issues.

So back to the carbs... The flat tops work great when they're working great. I'll even risk poking the hornets nest here and go out on a limb to claim "Better even that the round tops." Problem is, as with many other "better" systems, that improvement comes with the down side of complexity, and that complexity provides more avenues for problems to work thier way into the system.

The bottom line is, either carb choice works great if done properly, but the round top system is boatloads simpler than the flat top system. That simplicity makes it much easier to keep the round tops working properly and also to troubleshoot problems when they do occur.

I know the flat tops pretty well. But reaching that point is much easier to achieve if you aren't behind the eight ball working on your daily driver!

[porkbun]

Problem is that you've got no "baseline". You don't have any portion of the car verified, tested, proved positive, that you can be completely confident is working as designed.

I see what you mean. The only other detail that I can give is that the problems go away after the car is does some "work". This morning it was pretty chilly and I was experiencing some of that lag and my rpms were threatening to drop below 1k. 3 Hours later (7 miles away), I start it up with the choke, but the RPMs dropped to 8-900, but when I took the choke off, it went to a normal idle.

Ill pick apart the FSM and see if I can get anywhere tomorrow with the carbs, and maybe that set of appliance rims that came with the car will help soften the blow of switching/tuning the carbs if I cant figure them out. I cant just pour money into the car all at once, because I still have to pay taxes for it and get some new tires which is already about $800, so what do you recommend me doing first? Its pretty predictable right now, but I want to get it in good mechanical shape so I dont end up on the side of the road.

[Captain Obvious]

I see what you mean. The only other detail that I can give is that the problems go away after the car is does some "work".

Apologies ahead of time if I'm wrong, but I'm gonna go out on a limb and make some age related assumptions. I don't know how old you are, but I'm guessing that every car you have ever seen or been in to this point had computer controlled fuel injection systems and no choke. You got in - turned the key - and went off down the road without a hiccup.

Well let me tell how it used to be in the old days...

There was no electronic fuel injection or computers of any kind in cars. Cars had carburetors and chokes. When you first started your cold carbureted car, it ran "OK" if you were lucky, and "poorly" if you weren't. If you were lucky, you could let it sit at high idle for a minute or so to warm up before you went off down the road, and if you weren't lucky, you had to sit there for a minute and nurse it to keep it running. Then once it was running well enough that you felt confident that you could pull out into traffic without stalling in front of someone, you could get moving on your way. As you put a few miles behind you and the engine continued to warm up, it gradually got better and better until it ran "good".

The best you could ever hope for was that it started easy, idled smooth but tentative while cold, and improved quickly to the point where you were safe to leave your parking spot.

So what would I do? With the FSM as a guide, I would start with the easy stuff:

Ignition - Install new distributor cap, rotor, plug wires, and spark plugs. While you're in the distributor, check your ignition pickup gap. Once you have installed new components and verified your pickup gap, check your ignition timing and adjust as necessary.

Fuel - Check and adjust your damper oil as necessary (yes, you have a fill-to line on the damper stalk). Check your float bowl levels. I would assume that if your float bowl levels are OK at idle and you aren't running out of power on the highway that your fuel filters are not clogged (yet).

Air - Replace the air filter and inspect all the vacuum hoses and lines in the bundle of snakes and compare against FSM for correct locations of all the tubing. Vacuum leaks are not your friend, and because of the complexity of the 260's system, there's lots of opportunity for them to occur.

Keep in mind that this is just the simple non-invasive stuff. Beyond that are more invasive tasks like setting the valve clearances and replacing the fuel filters. Also keep in mind that I'm focusing on simple "performance" based stuff, and there is a lot of "safety" related stuff suggested earlier by SteveJ and LeonV like brakes and suspension inspections.

Keep us posted!

[porkbun]

I don't know how old you are, but I'm guessing that every car you have ever seen or been in to this point had computer controlled fuel injection systems and no choke.

That assumption is spot on. This car is more than double my age and Ive never seen a choke on anything besides gardening equipment, even those are disappearing now. It seems like most of my worries were just part of the operating instructions that arent in the manual. My Moms mechanic is biiiig on Volvos, and now that I think about it I actually remember seeing a couple of Zs and ZXs at his garage over the years. Hopefully he will know a thing or two about the SUs if I cant figure them out

That list will be added pretty close to the top of the growing list of my Zs to do list. My wallet and schedule will be taking a beating, and I havent even touched the body or the electrical yet! Its a good thing I wasnt looking for a car that would be perfectly reliable and never give me a reason to get my hands dirty. Thanks to everyone for helping me diagnose and plan a course of action and take the first steps on my Z journey!

[Bonzi Lon]

Well let me tell how it used to be in the old days...

There was no electronic fuel injection or computers of any kind in cars. Cars had carburetors and chokes. When you first started your cold carbureted car, it ran "OK" if you were lucky, and "poorly" if you weren't. If you were lucky, you could let it sit at high idle for a minute or so to warm up before you went off down the road, and if you weren't lucky, you had to sit there for a minute and nurse it to keep it running. Then once it was running well enough that you felt confident that you could pull out into traffic without stalling in front of someone, you could get moving on your way. As you put a few miles behind you and the engine continued to warm up, it gradually got better and better until it ran "good".

This is the exact same routine I went through in the winters of 77 to 79 in order to get to college class on time, 73 with flat tops.

Bonzi Lon

[Captain Obvious]

My Moms mechanic is biiiig on Volvos, and now that I think about it I actually remember seeing a couple of Zs and ZXs at his garage over the years. Hopefully he will know a thing or two about the SUs if I cant figure them out!

I believe they used SU's on some of the Volvos, so if he's got old Volvo experience, he should know his way around the Z carbs. Only question though would be is he capable of making the leap from the round tops to the flat tops like what you have... They are the same carb in theory of operation, but there are a few differences.

That list I put together was assembled with an attempt at "all things considered". By that, I mean, I tried to put together a list of things that wouldn't cost much, wouldn't be very difficult or require special tools or equipment, and wouldn't take too much time at any one sitting so you could still use the car as your DD while working on it.

My intention was not only to get you some possible improvements in how well the car worked, but also an expectation that you would get some experience and knowledge while doing that work. You could spend hours and hours and hours on making things perfect, but I know it's probably not the right time for that. Once you know your way around the car and have a handle on the FSM, you get to spend countless hours working on everything else! If it's running well once warm, isn't billowing black clouds, and has decent power, then you're doing as well as a lot of Z owners.

Well let me tell how it used to be in the old days...

This is the exact same routine I went through in the winters of 77 to 79 in order to get to college class on time, 73 with flat tops.

Haha! It's amazing to think how "spoiled" we are with todays cars... You get in, turn the key, and hit the road. I typically start the car cold in the morning, and have wheels turning no more than ten seconds after the starter has stopped spinning. No muss, no fuss... It just starts and goes.

We take it for granted now, but when you think about it, it's really amazing!

[porkbun]

Put 1k on the car and it had been running just as it had when I got it...until my friend brought me to a large open parking lot to do donuts. I couldnt pass up the opportunity to do a few donuts, but Im kinda regretting it now. It was really just turning hard in first in a sandy empty parking lot, but my car did not like that at all. My car suddenly started experiencing jerky hard acceleration (like I was pumping the gas pedal) and would randomly threaten to die at stoplights (putting down and running rough until I gave it some gas). Accelerating from first always feels like im just using the clutch completely wrong and I feel a ton of rubbing as the car starts move (from idle or above the usual 1.2ishk, the RPMs will drop to maybe 700 and then go up as the car starts to move). I also feel more of this rubbing when I try and accelerate and turn from a stop, but that might be because its harder to move with the wheels turned.

I decided to check out the air filter and though it wasnt that dirty, I did find a TON of tree nuts inside the housing. I cleaned those out and noticed a ton of play in my throttle arm linkage (id say a little less than half an inch).

Does the little boot of the arm coming from the pedal act as a spring? The one on my car is brittle and opened up. Does the play even really matter? I feel as if the throttle response is perfectly fine, but dont know if its contributing to the jerky acceleration.

From what ive read about vacuum hoses, it seems like theres a leak somewhere (my rpms will also drop if Im on the brakes hard for very long (like an exit ramp). I hope its just that and not my steering and/or clutch. Any recommendations as to replacing the hoses or learning more about them? Ill be a LOT less busy in a month and have plenty of time to pay attention to the car, but right now im so busy.

[porkbun]

I just noticed while under the hood that my valve cover breather hose(?) is saturated with oil and the valve cover has marks that show that some oil spilled/spurted out of the hose a while back. It also has some tape on it which seems to show that it isnt the first time this has happened. My mechanic should be back from vacation, so ill call him and see how much he knows about these cars