seattlejester's 1971 240Z

[seattlejester]

Another problem that came up during the autocross was fuel starvation. Part of me thought it was because it was autocross and I was running the fuel cell fairly low. It did seem to get better when I filled up the next day. 

 

Then I went on a local drive. A little over half way through the car started bogging and surging pretty badly running pretty lean even at low load. I could hear the pump cavitating. I filled up again and it seemed to go away after I let the car sit, and only returned after 30 minutes. 

 

Sent off the fuel pump for warranty in case it was going bad and started assembling a new fuel system. When it returned I threw it back on for a photo shoot only to find the fuel flow from the hose was less then the fuel flow from the fuel cell. I took off the inline filter to find it was about 1/2 blocked.

Even after a bit of cleaning it still had fine debris.

 

I think this stemmed from when I drained the fuel into a plastic fuel jug and when I poured it back in the little plastic bits from manufacturing also went into the cell. So the car would run ok until enough of the fuel passed through the filter to bring the debris into clogging the filter. After sitting the debris would basically backwash into the cell. Good thing is the filter did its job, and being reusable is a wash away from being clean.

 

However I had already started down the road of replacing the cell with a tank. Thanks to posts by Joe and a lot of feedback from Omar I decided to go with a camaro tank. That was a whole ordeal in and of it self to acquire and prepare it.

 

We tigged this frame together, only to find it was too long and wouldn't sit on the mounts I had from the fuel cell.

So it was modified to allow it to slide in at an angle. 

A wee bit of undercoat to keep it from instantly rusting.

If desired, the tank could be dropped with the straps, and then the subframe could be removed if needed.

Much more discrete then the fuel cell that used to be there.

The GM sender is also a different ohm range than normal and really difficult to design. I did find a gauge online that worked, but it kind of ruins the current scheme I have going on.

Might have to slowly convert everything else around it now, but the gauge has the startup dance, a really nice back lit LED and when you get low on fuel the gauge buzzes and the logo at the bottom turns orange. Not bad for $40 or so.

 

[Zetsaz]

That's awesome! Nice to see the new tank is in and working

[seattlejester]

Thanks for answering all my questions, it is a bit odd not hearing the pump, but at the same time quite nice to have one noise gone.

[caperix]

The fuel tank subframe looks great. My winter project is to put a Camaro tank in my 260. Do you have any more photos of the install?

[Exposed]

that tank is a good idea, looks like it was meant to be there. I need to either clean out my current tank or repair/ replace it, was having a similar issue when the car was on the road. What year camaro is that from?

[seattlejester]

Thanks, I think I am going to try and get some lift time soon and I'll grab a few more photos.

 

It really does look like stock, maybe even better with the speed grooves. The tank is from when they switched over to the LS-1, so 99+ I believe.

 

Notes while I still remember.

 

Most parts you can buy from rock auto, straps, hardware, fuel fill neck, gas cap, lock ring, etc.

 

The Spectra V6 pump says it will push 50gph, but I'm not sure if that is true, I have the pump, but I've never tried it. Their pumps are clipped into a plastic ring and are not readily replaceable other than another spectra pump so be advised. The stock style bucket was found on amazon for about $30, it has the rubber sleeve, jet pump assembly, etc. You can get a stock replacement for something ludicrous like $5-700 from the parts store. Racetronix sells a plug and play kit for the STOCK bucket. It puts a 255lph pump that uses the jet pump and is all wired up, but it is for the STOCK bucket, if you use aftermarket they switched to wider tabs for the fuel pump wires and the plug will not fit.

You will have to harvest the new pins from the new bucket and crimp them onto the thicker wires from the racetronix kit.

 

The part that is seemingly non existent is the fuel fill hose that connects the neck to the tank. According to the junkyard they cut those to drain the tank. Given the tank has a roll over valve that seems completely unnecessary, but I believe the stock fill neck is welded to the car so it may be how they remove it easily. I found a hose for an old jeep that is the correct diameter, if you can find 1 inch hose rated for gas as well as some 1 inch hose barbs you will be in business, I could not find any locally. Still looking for the right fittings.

Company/part number: Omix-Ada 17740.05 it seems to have sufficient bends and curves to figure something out with some couplers/90 fittings.

 

Note the V6 and the V8 tanks are identical as far as I can tell. The internal bucket mechanism is different. My setup is a combo, I have the top half of the V6 bucket and the lower portion of the V8, the only benefit is that my fuel return goes straight back into the bucket instead of shooting out from the removed regulator port, not sure if it will make a difference. The difference once again is the V6 has a feed and return and dumps into the bucket, no regulator in line. The V8 setup has a regulator built into the bucket and will not return until 70psi or so. 

 

I am pretty sure these are the fittings I used to adapt to the top of the tank

https://www.amazon.com/Russell-640853-Quick-Disconnect-Female-Fitting/dp/B001P2CKVY/ref=sr_1_15?ie=UTF8&qid=1548038859&sr=8-15&keywords=3%2F8+to+6an+quick

I already have 6 an line so plug and play.

 

The pump needs to be primed on your first go around, preferably with adequate fuel. I had it all installed and poured in a few gallons into the tank and the pump wouldn't circulate. Pulled it out and filled the bucket a bit and it gurgled then started pumping. Make sure you prime it the first time before you load it into the tank.

 

The bars to mount the tank against should be about 2 inches wide (note the frame, not the straps). Make sure you use foam on the pressure points, you can see where they used it on the factory tank from the cut outs they have for it (weather strip foam bought at home depot). 

 

Ohm range is like 40-250 for the sender. Not many gauges seem to do this range.

https://www.ebay.com/itm/Fuel-Gauge-2-52mm-full-ranges-LED-low-fuel-warning-001-F-BB-17/261697663603?hash=item3cee657273:g:PukAAOSwKSRa4yMw:rk:30:pf:0

That is the one I bought and it works well. Pretty nice as mentioned above.

 

[seattlejester]

Gas tank picture with a bit more lighting, I'll have to get it in the air to take a good picture to show location and fitment next time I get on a lift.

 

It has been a while. I bought a new daily driver that has needed some work, and I started up school again in addition to work which has sapped a lot of time.

The new member of the family. 

I needed something on the small side for city driving, that I could have a little fun with on occasion. It's been pretty good so far. The AC is the only real problem which is hopefully getting addressed soon, and I've replaced some wear parts, and I have a stack of some shiny upgrades will be making there way on as time allows.

 

On to making the datsun pretty and more pleasant all around.

 

Exhaust is definitely good, needs an additional hanger, but it is pleasant enough to drive without necessitating ear plugs, and with the windows up you can collect your thoughts. Still enough of a growl to turn heads.

 

Cleaned up the front radiator mount a little bit, friend Tig'd some new moounts for my intercooler to replace the washers I tacked in there ages ago.

Tire letters are in the process of coming off, and I think the rims may need a re spray. 

There is also a list of flaws from an outsider that has been generated that will systematically be addressed.

 

Edited April 1, 2019 by seattlejester

[seattlejester]

If I eventually make enough mistakes, I think my car will finally be sorted.

 

One of the things not on the list, but very apparent was a large dead zone in the brake pedal.

 

Turns out you can't just play legos with these cars. I was able to source and have rebuilt a 15/16th master a long time ago, and threw it onto the replacement early booster I bought. Turns out in 73 and later, they started using a longer cap/bolt on the pushrod on the engine bay side of the booster that sticks above the surface. So my 280zx 15/16 master was never going to work well with the shorter setup. Taking it off I found there is a fair amount of adjustment and adjusted it to match a 280z booster I picked up from the parts store. Turns out that one was poorly adjusted as well. I tested the brakes with the wheels in the air and made sure they released, but I'm guessing the booster has to see vacuum in order to be in its functioning state. I drove down a small street with no problems, then when I got on the freeway with the vacuum going suddenly the brakes gradually came on harder and harder until the car would not accelerate.

 

I was able to dial back the cap a few mm on the side of the road luckily being able to pull over in an extra wide shoulder and drive home without much issue, but please learn from my error. If you have this wonky combo, test your setup with the car running, and make sure you get some vacuum built up whether it is going down a hill or engine braking. 

[rossman]

6 hours ago, seattlejester said:

If I eventually make enough mistakes, I think my car will finally be sorted.

This my friend is how we learn  I've made many and I'm sure, despite my best efforts will continue to do so.

 

I have the same setup but haven't noticed a dead zone, but it was about 10 years ago when I installed the zx master cylinder and I don't recall what I did regarding the push rod.  I'll take note next time I drive the car.  I DID make the mistake of keeping the 7" brake booster.  It takes quite a bit of force on the petal to stop the car quickly.  Should have upgraded while I was at it...

 

Cheers,

Ross

[seattlejester]

Despite my efforts I'm sure I'll be chasing my tail, can't blame anyone, but myself in the long run.

 

I actually bought an 8.5 inch booster, but turns out the bolt pattern is pretty different. Might be worth taking a look at the length of the pushrod. I thought it was a squishy pedal and I needed more pre-load or something or I needed more booster, but when it was adjusted out and working the brakes were immediate and felt very modern in engagement. 

[seattlejester]

Goodness I love this forum, you really can find everything.

 

Quote from this thread:

DO NOT, DO NOT, DO NOT preload the brakes. EVER!!!

 

The master cylinder needs to fully release in order to open up the little ports that let the brake fluid back into the reservoir. If they can't release ALL THE WAY then they can't release the pressure.

 

This makes no difference at first, because you let off the brake and there is no pressure, then you step on them and there is, let off and there isn't. As the brakes gets hotter from you applying the brakes, say, in traffic, the heat generated transfers into the fluid, which expands. If the pressure can't release back into the master cylinder reservoir then this results in a light drag on the brakes. As the drag continues, more heat is generated, more fluid expansion, more pressure, more heat, more expansion, more pressure, etc.

 

I had this happen with my clutch once and I learned to have free play in the system. On the brakes you want a little free play in the master to booster connection, and you want a little in the pedal to the booster connection. 1/8" of free play in both won't make a noticeable difference in the pedal throw, but not having that free play will be a BIG problem.

 

Pretty sure that is what happened. 

 

I measured what I did and found that I was sticking 13mm past the flange of the aluminum spacer at first, that caused the pre-load on the master and the exact symptom of the brakes coming on and staying on. Then on the side of the freeway I moved it down to 6mm past the flange and the car drove back with no problems. I have it currently set to 9mm which is in spec, but I will be checking for preload and complete release to make sure I don't run into problems again. 

[seattlejester]

Miles also posted this image two days before this happened. I should have taken note:

Equates to 9.9mm past the surface.

[seattlejester]

Work has been interesting and been keeping me busy, but continuing on.

 

Twinning done correctly:

With the brakes somewhat adjusted (after that experience I decided to leave myself a 1mm buffer from the correct measurement). I tested it to find the brakes fully disengaged and the dead pedal throw was reduced by a good margin.

 

I added some rubber isolators to the tank strap bolts as well as loctite, sealed up the hole the new much smaller filler neck revealed, and fixed the fuel filler hose.

I even adjusted my hatch which has been loose for years causing a little rattle at speed if a microfiber towel wasn't put on the gasket to help put tension on the aerocatch latch.

 

The reason for all this was a drive a friend had setup. The last time we went, my car was in the middle of the full rear end overhaul. Right after finishing if memory serves I killed the battery and popped a fuse which until was found caused a lot of things not to work. Decided I was going to definitely make it this year.

 

It was supposed to be crummy weather, but as with this time of year it really is unpredictable. The morning started out overcast and cold, but glorious weather waited.

The car made it 140 miles with no real issues.

As the car ticked cool with the hood ajar, my copilot and I sat around waiting for the remainder of our group to arrive.

As much as I enjoy Z cars, it seems like all the locals *cough cough* are down or in progress at the moment. I swear it is some type of curse, only one running Z at a time allowed. However I really enjoy the mishmash of cars the last few drives I have done there were no two cars the same.

Had a nice beverage or two (don't worry I was the passenger), and we took off the long way back home through Packwood.

 

Turns out they had an autocross earlier in the day, may have to try and squeeze one of those in soon.

By the time we rejoined a major highway it was golden hour. 

And golden hour means great lighting especially for rollers.

 

So what does this road trip have to do with anything? Well it was the first time I filled up my gas tank to the full mark. With the filler neck hose from a Jeep I bought I was able to make it so that there was no noticeable kink allowing the fuel filler to fill at full speed. The full tank of gas also helped add weight on the rear helping damp balance some of the weight and giving the shocks more weight to play with. To top it off even at our brisk pace combined with some traffic the 3L turbocharged engine managed 360 miles with the 16 gallons. 22.5mpg. That was with some pretty extensive brisk driving. I imagine sticking strictly to cruise we would see something closer to 30 or so. 

 

Definitely some faults did rear their ugly head. The car is loud even with the cat and ultra quiet resonator, the first stint we did without earplugs, only when we stopped to stretch our legs did we realize how loud it had been. Some rattles definitely need to be chased. Under extensive driving the seats do get warm, I imagine time for some heat mat under the seats, maybe some insulation and carpeting. Driving position still sucks not sure what can be done short of cutting out the floor or finding some way to make the seat reclining mechanism narrower or jack the front of the seats up a couple inches. There also was some smoke coming up from the shifter, we didn't find anything more than a bit of oil dampness not even dripping, so perhaps it was the adhesive used for the tunnel shield slowly cooking off.

[rossman]

Congrats!  Sounds like it's a pretty well sorted car!  How well did it hold up to the other cars? I love the e30, my favorite beemer. 

[seattlejester]

Thanks!

 

We really didn't get a chance to do much comparative driving, the route was long and our breaks were long and we had things to do in the evening to find emptier roads. I would like to imagine in a straight line and maybe even in the twisties I would give all of them a good thrashing , I've played with the BMW before and he had a hard time keeping up even with my wonky fuel pump. I think other than the porsche we were the only car to make it on one tank of gas as well. 

 

I think I have a soft spot for the facelift E46, but I do enjoy the E30. His especially, I've never been taken around a corner as hard or quietly. His old setup was running a double muffler so the only thing you would hear would be turbo spool.