Poindexter Posted May 15, 2008 Share Posted May 15, 2008 Greetings all. I tried to search for answers in the forums here- without a clear enough answer. I promise to read the "How to Restore Your Z" book, but for now I just noticed a broken fitting on the engine, as well as noting the apparent lack of several vacuum hoses, and I'm freaked that I might be damaging something by driving it- it is my EDD now, so I really could use some advice from that huge well of experience that all of you people possess. It's a 2/71 vintage, HLS30-23788, under 70K miles, and always garage stored- totally dry and clean- for most of the past 15 years. California car with almost NO rust and totally clean floorboards! It's all stock except for the 5-speed- with a very short first gear- so probably came from a turbo(?) I put it back on the road 2 weeks ago and did a LOT purely mechanical restoration work like all new clutch master & slave, brake master, ball joints, tie rods, etc...that kind of stuff. It was tuned then too, as well as having everything either cleaned out or replaced- like the gas tank, radiator, all filters and fluids, new braided s.s. brake lines, all new belts and hoses, new battery, etc. Trans oil was dirty but showed NO water or metal filings even on the magnet plug- and the trans gear oil was just replaced with RL MT-90. It only took 2 quarts- so I wonder first if that's a bit too little by a half a quart- or so I've read? Mechanic sure it was filled properly. It did have the carbs rebuilt 4 years ago, but it still sat from then, and wasn't driven at all until recently. That being said it drives nicely, a bit clunky on bumps, and it shifts a bit rough until warm, but nothing else apparently glaring. It will need all new bushings, no biggie, but nothing stands out except for the rough acceleration on partial throttle only, a long pedal mve until the brakes engage- but then they work ***perfectly*** and a heavy fuel smell from the exhaust, and a touch of oil smoke. NO loss of coolant at ALL. After thorough local slow-speed-driving-only trials, it drove perfectly on the highway, tracking perfectly with only a tiny 50MPH shake. I've still kept it well below 5000RPM, especially when shifting. I'm treating her very carefully. Other symptoms- It has no pep from idle until apx. 2500RPM unless you really step on it, otherwise it stumbles badly if you don't give it a lot of gas. If you do give it enough throttle, it seems to run just fine, revving smoothly and pulling hard. It also does burble a lot on deceleration, and it does smell like it's running rich from the raw gas smell in the exhaust from outside the car. And the brake pedal travel is too much until it engages- like half-way. Now for the pictures of the main problem area mentioned above. The broken fitting on the left, for a 1-inch hose, goes right into a "T" and the front half goes forward then drops under the A/C compressor. The other concern are the two unidentified parts- one of which I think is the throttle servo, the other I don't know- which have bare stubs that seem to be looking for hoses to attach to them. I am primarily trying to find an experienced mechanic with significant experience in Z's near me in NJ, but with no luck. I know enough that I will need a good mechanic to diagnose these problems- just as I know it will take a lot of time and effort until I learn enough to diagnose and then do some of this work myself- as I don't always have to rely on others, not to mention the huge potential expenses involved. Can anybody *please* help now with some suggestions on these problems? And maybe even come up with a referral to a good mechanic in the NJ area? I imagine the responses here might include having the carbs rebalanced again, as well as having the mystery vacuum lines re-attached, but I'm hoping it's something I can do myself- and now! I do learn quickly, and I must say, modestly, that I know how to use most tools quite well, and have for many years. My Dad always had a huge tool bench, and taught me how to build, work on and repair almost anything- except for car repairs of course! I do have good hands, having built things like tube radios and audio amps in the past. It's just that I'm lacking the critical experience in this very specialized area. I realize I'm asking a lot, but I'm in a bit of a pickle now, with this being my only driver- at least until I can find a newer car to use as a DD- like a 1980's vintage MB 300SDL! link to my photobucket pictures of my car and the areas in question- under the name of Poindexter333- http://s277.photobucket.com/albums/kk60/Poindexter333/ THANKS!!! Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted May 15, 2008 Share Posted May 15, 2008 The broken fitting on the left, for a 1-inch hose, goes right into a "T" and the front half goes forward then drops under the A/C compressor. The other concern are the two unidentified parts- one of which I think is the throttle servo, the other I don't know- which have bare stubs that seem to be looking for hoses to attach to them. What I see in this picture is very typical. The piece with the broken fitting is a valve which would normally be connected to the air pump (aka smog pump) under the A/C compressor, the other hose off the "T" goes to the anti backfire valve then continues into your balance tube. The other two pieces that are missing vacuum lines are for controlling your throttle when shifting, they are only used on manual transmission cars so you would not see them on an auto tranny Z. If you are not having problems with the car being jerky when you shift I would not worry about those. If the smog pump is removed I would not worry to much about the broken part either BUT if that valve is leaking by it can certainly cause some strange problems mostly with your idle but also potentially your fuel milage and back firing. Most people remove that entire system thinking it makes the car run better but that is not really the case, most of the time it just makes the car spew higher emissions, so in my opinion you should try to fix it before you try to remove it. If you do remove that whole system make sure you remove all of it and completely seal every hole left from the removal. Dragonfly Quote Link to comment Share on other sites More sharing options...
Poindexter Posted May 15, 2008 Author Share Posted May 15, 2008 What I see in this picture is very typical. The piece with the broken fitting is a valve which would normally be connected to the air pump (aka smog pump) under the A/C compressor, the other hose off the "T" goes to the anti backfire valve then continues into your balance tube. The other two pieces that are missing vacuum lines are for controlling your throttle when shifting, they are only used on manual transmission cars so you would not see them on an auto tranny Z. If you are not having problems with the car being jerky when you shift I would not worry about those. If the smog pump is removed I would not worry to much about the broken part either BUT if that valve is leaking by it can certainly cause some strange problems mostly with your idle but also potentially your fuel milage and back firing. Most people remove that entire system thinking it makes the car run better but that is not really the case, most of the time it just makes the car spew higher emissions, so in my opinion you should try to fix it before you try to remove it. If you do remove that whole system make sure you remove all of it and completely seal every hole left from the removal. Dragonfly Wow! Thanks for such a comprehensive answer! This car is jerky shifting personified!!! (I do have the 5-speed) Funny, but I didn't remember my shifting technique ever being so bad in the past, as I thought the bucking bronco ride had to be something I was doing to cause it. So I guess I must replace all of the vacuum lines immediately- which seems easy enough. Is there any way you might know of a link with the schematic for the proper configuration for the vacuum lines for the 2/71? I have searched extensively and have found almost everything I've looked for- *except* for the proper schematic for the vacuum system! And are the vacuum and anti-smog "sub-systems" entirely separate? As for the smog system, should I try to recreate the whole assemblage- or nothing at all? I guess the temp fix would be to completely seal the whole thing up until I get all of the parts together? I also have the symptoms you relate- like backfiring, so I will try to restore the system. I am all for cleaner air- and I have no desire to eek out every last newton/foot or whatever unit of energy- but I don't want to open myself up to a nightmare either, since I'm not sure if I still have the pump and the anti-backfire valve- I'll get under the car at first light. Are these expensive or tough parts to find- and is it an all or nothing at all deal with respect to the air valve and the other smog parts? Is it fair to assume that there is a significant horsepower drain with the smog controls in place? I kind of remember the gas craze during the 70's where it was the latest thing to bypass this "stuff", and even though NJ has a waiver for cars of this age- in that I don't have to have any emissions inspection- I do want to do everything I can to (1) make the car run as perfectly as possible, for as long as possible, and also (2) not spew noxious fumes everywhere I go. I live very close to one of the most gorgeous National Seashore Parks- Sandy Hook- and the pristine surroundings and perfectly clean air are major parts of the draw there. But for the few hundred miles I'm gonna drive, I don't want to drop another $500 either! Am I to assume the smog system and the vacuum system are both a must though for optimum performance? See, I already have to deal with that lovely "Z gas fumes" issue to deal with yet- probably due to the psychotic design for the gas venting system. I am trying to learn as much as possible about this car! Thanks again Dragonfly! Quote Link to comment Share on other sites More sharing options...
DatsunD Posted May 16, 2008 Share Posted May 16, 2008 I had a simalar setup on my 260z, i took most of it off and have no problems with my duel dgv webbers. I still have my headers with those smog pipes coming off of them in my shed with the same looking valve as your broken one, let me know if you need it. Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted May 16, 2008 Share Posted May 16, 2008 Most people believe that removing the smog equipment will help the car so a lot of people have those parts laying around and would probably give them to you for the cost of shipping. I personaly feel that unless you are racing the car there is no real need to remove the smog equipment. Here is a link that should help you out a little and get you moving in the right direction: http://www.autozone.com/az/cds/en_us/0900823d/80/1d/1a/32/0900823d801d1a32/repairInfoPages.htm also don't be afraid to look for any other diagrams etc. that you may need from that same link. It would probably be in your best interest to buy a factory service manual for your car, it would make it much easier for you to hook up and test everything. For your raw fuel smell check the hoses on the evap tank that is in the back of the car on the passenger side (inside the car behind the plastic that is nearly impossible to remove), there are also two fuel hoses that come up through the floor in the back of the car behind the plastic that covers the tail lights (remove the entire cover), these hoses should also be checked and the rubber seal between the hose and the "tube" the hose comes through should also be checked, if it is badly damaged go to an RV store and ask for a roll of "dum dum" tear off some and stuff it into the tubes around the hoses to seal that potential leak. You can also get raw fuel smell from the front of the car, if your carbs are not set right and spewing gas fumes they will make thier way through any openings in your fire wall and your cowl vents (where the wipers and wiper motor are) this is the area where your ventilation gets its fresh air from and if fuel vapors are getting in there you will get them inside the car also. Dragonfly Quote Link to comment Share on other sites More sharing options...
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