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Powerglide

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Everything posted by Powerglide

  1. Did the wear spot in the middle of your old rack cause play in the wheel (like on a worn 1956 Chevy) or did it give a lot of kickback in the steering wheel when hitting a bump or pothole in the road? Just curious. Thanks!
  2. Not braggin... And I can't tell you why. But my 76 EFI Z has cheap eBay radiator. 180 degree thermostat, a header (under stock Heat shield), a/c with a Sanden 709 compressor that's always running in our south Florida July heat STRUGGLES to get over 185. That's even after a 15 mile cruise at 80 mph and stopped at a traffic light for 4-5 minutes. It's got the ORIGINAL Paraut fan clutch and a 50/50 ratio of regular old yellow Preston. Thing is...the hotter it runs---the better it runs! I've run 190 thermostat, even here in summertime. But it doesn't seem right, and the extra latent heat inside the car is a REAL challenge to cool. Even with R12. And a 3 or 4 hour heat soak after a hot shutdown will WORK any cooling system or A/C system. Oh, and prior to installing it in my garage. I sprayed it with a light coat of Krylon semi-flat black purely for the cosmetic value. That should REDUCE heat transfer somewhat.
  3. Get the Sanden style 709 with the bracket that eliminates the tensioner. Get the airflow THROUGH the condenser and the evaporator and you'll get mid to high 30s center vent temps as mentioned above. Might check that fan clutch to ascertain whether it's functioning properly. You'll love that cold air in 95 degree weather. My 76 280z stays cool inside in July in South Florida. Stock blower and squirrel cage on the 280z works well enough. But a friend's Honda blower motor will mess up your hair it blows so strong.
  4. You shouldn't be hearing a lot of "Zs with exhaust leaks" any where. If you are then the shade tree "mechanic"/owner did a terrible job installing the manifold/header in the first place. The cheap header on my EFI 76 has been there for 6 years and 50,000 miles and it doesn't leak. Suggest you do the work yourself. Very few shops out there will the work properly. You'll be much happier in the long run. And you'll avoid the absurd markup on parts.
  5. You can get ALL the parts you need from Oliver at Z Specialties in Washington state. Yheir number is 800-518-5480. Tell Oliver Joe (aka Powerglide) in Lake Worth, Florida referred you. He and his wife run the business and are very helpful. He'll give you all the free advice you need. Just remember to buy some parts from him from time to time.
  6. GREAT car. Lots of good info with the photos. To get the stock EFI to run properly and as designed, you'll have to remove the breather on top of the valve cover. The EFI in these cars is designed to run as a closed system. ANY vacuum leaks (and yours has a BIG one due to the breather) totally defeats the factory design of the system. You'll need the FSM. Replace the breather with the factory components, hoses, clamps and adaptors and the system will function as Bosch and the Nissan engineers intended. You'll prpbably have to adjust the AFM several points leaner for it to run right.
  7. You're probably gonna have to replace the entire evaporator. Try AMC Imports in Texas.
  8. I grew up in Kendall about 3 miles from the Z Shop on US1. Dad bought a white 1977 2+2 new. I was 10 at the time. Chances are you worked on his car as he frequented the shop several times before trading the car in. The dealer was useless when it came to repair and maintenence. Small world.
  9. If your 280z has "throttle hang"...look for vacuum leaks. Then check the BCDD. If it's out of adjustment, rpms will hold between shifts and perhaps even rise when the load is removed from the motor when you push in the clutch.
  10. If your 280z has "throttle hang"...look for vacuum leaks. Then check the BCDD. If it's out of adjustment, rpms will hold between shifts and perhaps even rise when the load is removed from the motor when you push in the clutch.
  11. Agree with Tony on this one. Keep the rpms above 3000 on an EFI car. The flap in the AFM will be close to open and the car will respond nicely, not "rev slow" and you'll get PLENTY of engine braking. On surface streets around town, most poeople drop in to 4th gear. The car is sluggish when turning only 2400rpm at 45 mph. I cruise around town in 3rd gear a good percentage of the time. Above 50 mph or so I'll go to 4th gear. Or I'll use fourth at slower speeds if I don't need the "snappiness". Power band on these EFI cars is 3500-5800 rpm. Torque peak is 4400 rpm. The L series motors are NOT American V8s. Driving them well takes an ENTIRELY different tecnique.
  12. Chances are the compressor is locked up and will need rebuilt. From the looks of it...it also appears to be leaking. Lots of oil around the seals.. If you evacuate, replace the drier and recharge, you might have a catastrophic leak and/or failure somewhere in the system. The York compressor was not particulary efficient, even when new. Best bet might be to redo the entire system including a new/modern compressor, drier, evaporator, hoses, expansion valve, and a better blower motor. Rebuild or replace the fan with a stock 280z clutch fan. Parts and labor will be expensive though. Maybe upwards of $1500-$1900. Unless you do the work yourself. Kits with modern components are availible from MSA and other sources as well. But if you're not building a show car with all stock components and you want cold air in 90 degree heat...you'll have to strongly consider NEW components, CORRECTLY installed and charged.
  13. The Hitachi is a good compressor. It does put a heavy load on the motor compared to a more modern compressor though. You'll feel it in the lack of off-idle snap and dramatically lower gas milage. Like 2 or 3 MPGs worse. But you WILL get cold air if the system is set up properly. The ancient flared factory fittings are ok (if they haven't been over tightened) with R12 in that they don't leak. But I will tell you this...R134a WILL tend to leak from the stock fittings and connections in these cars. And remember---R134a runs at slightly higher pressures than R12, exacerbationg any leakage that might not have been present with R12. The BIGGEST problem with the stock system is a lack of airflow from the vents. The stock fan just does not move that much air, even on high. 40 degree air is great and considered the standard (that's what I get from mine too). But a lack of volume will NOT cool the car well on a really HOT day. The car will be comfortable with outdoor temps in the 80s. But in my experience, the stock a/c will not keep the interior cool when temps get much over 90 degrees, especially with lots of humidity. Tinting the windows---especially the hatch---will help considerably. An auxillary electric fan will help, especially in traffic and if the compressor has some miles on it. Remember, the key to cold air is AIRFLOW ACCROSS THE CONDENSOR. There is an outfit out of Texas that will sell you a NEW evaporator with expansion valve for about $400. That may be your only option these days. I'v heard mixed results with those Sanden compressors. They work. But NOT like a new car. And there's nothing worse than pukey 50 or 55 degree air from the vents on a humid 93 degree day. Especially when it takes 10 minutes to get there. You just won't stop sweating. Takes the fun out of driving the car.
  14. Thanks... But R134a is NOT an upgrade in any way shape or form. It's considerably LESS efficient than R12, operates at higher pressures, and tends to leak in older systems. Plus R134a is up to $15 a can. R12 can be bought via for abut $25 a can. So the cost difference isn't too bad. And the environment will be just fine. It's my sweating brow that I really care about! The new compressor will operate with R134a or R12. To your point...it's the oil that doesn't mix well. This whole thing is particularly aggravating because the old/current compressor gives 40 degree air on HOT days on full fan speed. It just won't hold a complete charge for more than a month. Thanks again!
  15. That's probably good advice. I ordered the NEW SWP123 compressor today. Will replace the drier also. When the reman unit was installed 5 years ago, I replaced the evaporator, the expansion valve, the condensor, the drier and the high pressure switch. The system was flushed, and a vacuum was drawn for 45 minutes. The system will produce wonderful 40 degree air on high fan on a 90 degree day here in Florida. The compressor is also quiet. Unfortunately, it requires a 12oz. can of R12 ($25 a pop) every 4 to 6 weeks. The leak is almost entirely at the front compressor seal. Although there is some leakage at the drier as well... In the past, I could top off once a year...but the leak has gotten worse over the last 8 months or so. I really don't have a choice---hence the new compressor. I CANNOT live without a/c in south Florida.
  16. In all fairness...I posted this exact same question on another board. Forgive me if you are offended. The remanufactured SWP123 a/c compressor in my 76 280Z has developed a significant leak at the front seal. The compressor has been on the car and in service for 4 or 5 years. I can get a NEW SWP123 compressor. But in certain circles it is said that the MJ167 is a better/more efficient unit. Any consensus on this? Can you back it up with the facts? I'v only found the SWP123 availible NEW. The MJ167 seems only to be availible remanufactured. NEW is almost always better than reman. But in this case----I'd appreciate some guidance.
  17. but hate the constant fixing and tinkering with the crude stock fuel injection system The stock EFI should'nt need "constant fixing and tinkering". It's probably one of the simplest, most basic and DEAD relaible FI systems ever produced and installed on a regular production engine.
  18. Iv owned both. My last Corvette was a 67 Big Block 4 speed with sidepipes and a 4:11 rear. Subjectively the car was a ball. The POWER, styling, noise and ooh did I mention the POWER! Handling feel...well, pretty truck-like. Your butt sits almost directly on top of the rear wheel. so lots of bump-thump, jiggle and body motion. My car had the stock 7 leaf rear STEEL spring and Bilstein shocks. The ride was OK on fairly smooth roads---but TERRIBLE on bumpy, wavy surfaces. The C3 chassis was developed in the late 1950s. And the driver is ALWAYS aware of this on the road. When the bushings, ball joints, tie-rod ends, shocks, springs and tires are fresh the car actually has a fairly tight sports car feel. But add a few thousand hard miles and frankly, compared to an S30 the C3 is a squirly, loose, rattly, ill handling beast that can be DANGEROUS with all that power! Make it a convertible or add T-tops and WOW what a rat. An S30 is far more comfortable at high speeds (70-100mph) than almost any STOCK C3. The later C3s (78-82) had a composite/fiberglass rear spring that made a world of difference with RIDE quality. Power steering helped quite a bit too. The rear suspension on a C3 isn't terribly well located. LOTS of TOE-change. Lots of roll-OVERSTEER. Lots of BUMP-STEER. Again---60,000 miles down the road only made things SQUIRRLIER, looser and less secure. S30s do this, only less so. All things being equal and when everything underneath is NEW---compare a C3 to a contemporary OLDS 442. Compare a S30 to a Porsche or an Alfa Romeo.
  19. The knock could be coming from the timing chain, the main bearings, the rod bearings, the valves, or the rocker arms. Or maybe the a/c compressor, the transmission, or the clutch.
  20. Every Z car I see has the de riguer red, high voltage MSD coil in place of the stocker. Which begs the question: Is the MSD coil one sees on most Zs a mismatch/misapplication when it's used with the stock ballast and stock ignition on a 75-78 EFI Z?
  21. Sounds like a weak pick-up coil in the distributor or low fuel pressure?
  22. Just took a 4 tank average. 1976 280Z, Stock EFI, 205 65R 15 tires on 15x7 Konig Rewinds. 93 degree heat in S. Florida, A/C on the entire time. Car has factory 4-speed and the usual R200 diff with 3:54 ratio. Driving is about 60% city 40% highway. I drive it moderately hard... Plenty of down shifting and 80mph runs on the Florida TPK. No effort made to "keep my foot out of it". Mobile Gas 89 Octane with Summer Blend 10% ethanol (hurts MPGs) Results on 4 tanks---17mpg Overall--never worse than 15.5 mpg---city/stop and go ONLY with a/c on. Best ever is 23mpg at 75 to 80MPH with the a/c off in cooler weather, ONLY on the highway. A lighter foot might stretch this a little. But an overdrive would put the car into the mid to high 20s on the expressway. A little MORE COMPRESSION would help a lot too. But the motor only has 159K on it...
  23. Adjust the valves. Bump the timing to 14-16 degrees. Run some Seafoam thru. I'll bet your numbers increase by about 10 psi. Take the car out on the highway and run it HARD for an hour or so. It'll run much beter afterwards. These EFI cars tend the run rich with age. That in turn causes sludge, carbon and sticky rings---which will lower compression. Puttering around town and lack of use is the WORST thing for EFI Z Cars. Fresh oil, some meticulous routine/preventative maintenence and some hard use (NOT abuse) will work wonders for your car!
  24. I can't prove it with the data you collected. But...I'd bet that a properly tuned STOCK EFI system with the SAME exhaust would be within 2-3% horsepower/torque/milage of both the systems you tested. The carburetor WILL be easier to tune! At least for me. But I like the stock EFI.
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