Miles

Trouble shooting automotive electrical problems is a different skill mix compared to engineering. As a retired mechanical engineer I enjoy the hands-on problem solving.

Did you remove the marker lights? There are two wires connecting the marker lights. Did you reconnect the wires correctly? For example, on a 240Z rear marker light one wire is hot and the other wire is a ground. When I had my 240Z painted, the shop hooked up the right rear marker light backwards so each time I turned on the lights the fuse for the parking/marker/dash lights would blow. When things like this happen ask yourself what did I do to the car just before the fuse started blowing. Like retracing your steps to find lost keys.

Not with paltech. But I bought a set of SU carbs from Ztherapy when I discovered that the throttle shaft bushings were leaking. At that time (2004) a set of Ztherapy carbs ran about $600. If the throttle shafts had been air tight I would have just bought the Ztherapy rebuild kit. I see Paltech rebuilds SUs: http://www.paltech1.com/id4.html

Forgot to mention that. If the bushings are worn air will be sucked in around the throttle shaft creating a lean condition and make it impossible to properly adjust the mixture. Typical symptoms of leaking shaft bushings include rough idle, lean sag and backfiring through the carb. If the bushings are suspect you can spray carb cleaner etc. on the throttle shaft ends with the engine running and listen for the engine speeding up or smoothing out. Ztherapy fixed this problem by replacing the throttle shaft bushings with sealed bearings.

If you are new to SU carbs then you need to buy the "Just SUs" video at http://www.ztherapy.com/ After viewing this video you will be able to maintain, adjust and repair SU carbs. Ztherapy also carries parts for SU carbs. If you Google SU carb adjustment or SU repair you should get many how to work with SUs write ups by Z car owners. Also, search Hybridz and classiczcars.com as there are many posts on maintaining SU carbs. In addition to the video, download a pdf copy of the factory service manual (FSM) for your year Z from the Links forum. Look here too: http://atlanticz.ca/zclub/techtips/carbs/su/index.htm

See if you can Google a pdf copy of the 78 280Z schematic. The pdf is easier to read and you can enlarge it to better see the details. See AtlanticZ for some electrical schematics: http://atlanticz.ca/zclub/techtips/electrical.htm

Here is a thought.................. http://www.thezstore.com/page/TZS/PROD/11-3280

What year 240Z, 280Z, 280ZX. 300ZX?

Sometimes. There is no 'generalized" answer without knowing the specific brake configuration you are asking about. See Brake FAQs and the other posts in the brake section etc.

Once you watch the video you will understand why your carbs are not working when you move the throttle linkage. The linkage that you are pulling on the bottom of the carb is the choke which causes more fuel to enter the carb as long as you hold the choke open. On the other hand, the throttle linkage only opens a butterfly valve. That's it. Basically, fuel flow into the carb is controlled by the piston lifting a precision tapered needle up inside its tapered valve seat which allows more fuel to drip out of the bowel and get sucked in by high velocity air into the carb where it is mixed with the air forming the correct air-fuel mixture. Some refer to this as a "controlled drip". Mixture adjusters on the bottom of each carb determine the correct mixture. It is a bit long and complicated to explain how the SU carb, throttle and linkages work. The video explains the theory of operation along with tuning which is the best way to learn SUs. Or download SU instructions off the net.

If you are new to SU carbs then you need to buy the "Just SUs" video at http://www.ztherapy.com/ After viewing this video you will be able to maintain, adjust and repair SU carbs. Ztherapy also carries parts for SU carbs. Do you know about the mixture adjustment nuts on the bottom of each carb? If you Google SU carb adjustment or SU repair you should get some how to work with SUs write ups by Z car owners. Also, search Hybridz and classiczcars.com as there are many posts on maintaining SU carbs.

Take your time and buy the cleanest, rust free and unmolested Z you can find.

Suggestions: If doing a V8 swap buy the Jags that Run (JTR) book and read it at least 5 times. Download a Factory Service Manual (FSM) and buy a Haynes repair manual for your specific car. Download electrical schematics for your car. PDFs are easier to read than those found in books. Buy the book How to Restore Your Datsun Z Car by Wick Humble. It will save you hours of searching. Focus on searching Hybridz as 99% of questions have already been addressed. Make a detailed plan with parts list including cost. Start bookmarking Z car parts suppliers - there are many! Remember these are 40 year old cars and will need restoration to be safe and drivable. Join ClassicZCars.com website and search there as well. Become well informed about modifications before asking questions. People will be more inclined to answer informed questions. Have some money. I stopped counting after $12k. Read the new member FAQs. Useful Links: http://zhome.com/ http://www.atlanticz.ca/index.php/tech-tips.html http://www.classiczcars.com/index http://www.zcarparts.com/ http://www.blackdragonauto.com/zZxCatalog.htm http://www.arizonazcar.com/

Well I guess we could rip off Mike Knell who wrote the JTR manual and post a picture of the entire page in the manual that explains how to hook up a 280Z tach to a Chevy HEI distributor.

He says that he has an HEI distributor.

The Holley Street Avenger uses vacuum secondaries which can be adjusted using their secondary spring kit. Let us know how it works out.

Your car sounds good otherwise. You are not running a big engine so the mechanical fuel pump should be ok. I know the Edelbrock tuning guide well. I tried a variety of jet and metering rod combinations without any improvement. Another problem I had with every Edelbrock carb was stalling under hard braking or cornering. It is a float thing. I finally concluded that I could use the Edelbrock carb as boat anchor and replaced it with Holley Street Avenger five years ago. Did one dyno run and haven't had any issues since. Please post how you resolve this.

What have you checked so far? Check the basics: fuel pressure, float settings, jets, metering rods, advance etc. If the problem exists after diagnosing the usual things consider: I had a similar problem using Edelbrock 650 cfm carbs on two SBC 350 240Z projects. After wasting a lot of time and money "tuning" the Edelbrock carbs, I switched to Holley Street Avenger carbs and the engines no longer boged plus the off-idle throttle response was excellent. The difference between Edelbrock and Holley was night and day. Out of the box the only thing I did with the Holley was to use stiffer springs to delay the onset of the secondaries.

That master cylinder is a "fast fill" or "step bore" master cylinder designed to work with "low drag" brake calipers. Fast fill calipers have a seal that withdraws the piston further back in the caliper bore so the pads do not ride on the rotor hence they are "low drag". That bulge on the side of the master cylinder contains valving to work with the step bore piston which provides an extra volume of fluid at the beginning of the stroke to make the low drag caliper piston move out of its resting position to push the pads into contact with the rotor. After the initial push of fluid, the master cylinder works like any other master cylinder. If you have a car that doesn't have "low drag" calipers and you install a fast fill master cylinder you would experience a higher, but stiffer, pedal. However, if you have installed disk brakes and a larger master cylinder and still have a long pedal this might be a solution to reduce pedal travel. I haven't seen anyone try this.

You will need to consult the factory service manual (FSM). Look in the downloads forum for Xenon where you can find a pdf of your specific FSM.

So is your car a Honda, 240Z, 280Z. 280ZX, 300Zx or should we guess????

All of that JB weld will have to be wire brushed off and you will have remove the barb on the end of the tube. The use of the compression fitting requires that the tube be smooth, clean, free of burrs and bends etc. or it will not slip over the tube - very close fit. I used some fine emery cloth to prepare the tubing for the compression fitting. Since the the tube requires re-brazing, just pull the tank and have a -6 AN bung installed and braze the original tube closed. Clean up the tank and install a new sending unit while the tank is out. Or do as RB26power suggested. Recommend that you search more gas tank issues in HybridZ before doing anything.

Look at a schematic, other circuits run through the headlight switch as well. Note from the schematic that the headlight switch also switches on other circuits such as the tail lights, dash lights, running lights, parking lights etc. The contacts for those circuits can be dirty or distorted such that no contact is made. Those contacts can be repaired. Over the years I learned that whenever the lights mentioned in this thread were out I found the headlight switch to be bad. So I keep a set of working turn signal and headlight switches around to use when diagnosing light problems. It takes but a few minutes to swap in a known working headlight switch. If it works you are done. If it doesn't work then you have just eliminated a variable in diagnosing the light problem and can move on to the next step. Or you can use a schematic and volt meter to check each contact on the switch.

Check the headlight switch. Fast check is to replace the switch with one you know works. Or you can learn to check the switch wire by wire with a meter.

Some good info at Zcar.com: http://www.zcar.com/forum/10-70-83-tech-discussion-forum/122943-78-280z-heater-valve-photo.html Lost of threads about the 280Z heater at Zcar.com.