MGTS 6 Report post Posted Wednesday at 01:02 AM So I picked up an 83 720 (Z24) 2WD for pretty cheap. 140k miles. Body is decent, but it needs a LOT of mechanical work. I'm starting to make my list. It's the super base trim. No tach, no trip meter. I really want to get a cluster with a tach and trip meter, don't need the clock. Is my truck already wired for the tach? Can I just plug-n-play? How much blow-by is normal? There seems to be quite a bit. I've got 180-185 psi in all cylinders and adjusted valves to .012 hot. How advanced should the timing be at idle? I pulled and plugged the advance and set to 4 degrees. With advance connected it sits around 30 degrees advanced What are some good sites for used or aftermarket parts? I really need to replace the bench seat in my truck. I'm 90% sure it's not the bench that came with it. I also want to replace some light covers and could used a grilled that's not cracked Thanks! 1 Quote Share this post Link to post
datzenmike 37,270 Report post Posted Wednesday at 01:23 AM Tach and clock are plug and play 180 is very good so I can't see blow by being a problem. What do you define blow by as??? These parts are not really available as there isn't a market to support the sellers. Best option is to get them from another truck, as in a wrecking yard. Consumable parts, those that wear out like u joints, brake pads, calipers, drums and rotors, suspension parts and ball joints, bulbs and such go to any auto parts store such as NAPA. 1 Quote Share this post Link to post
MGTS 6 Report post Posted Wednesday at 06:11 AM I will get a video at some point tomorrow of the blow-by. How is the OEM support of wear items? I always try to get OEM seals and bearings 1 Quote Share this post Link to post
datzenmike 37,270 Report post Posted Wednesday at 03:29 PM Don't mistake normal condensation (steamy exhaust) in cooler weather. Goes away when engine warms up. Quote Share this post Link to post
MGTS 6 Report post Posted Wednesday at 08:31 PM Here is the video My other questions that haven't been answered yet. How advanced should the timing be at idle? I pulled and plugged the advance and set to 4 degrees. With advance connected it sits around 30 degrees advanced How is the OEM support of wear items? I always try to get OEM seals and bearings Quote Share this post Link to post
datzenmike 37,270 Report post Posted Wednesday at 08:54 PM Idle is way toooooo high. Should be 700 +/-. Above 800/900 the distributor will begin to add centrifugal (or mechanical) advance. Make sure engine is warmed up before setting anything. 4 degrees advance before TDC is correct. Follow the vacuum advance back to it's source. It should go the the outlet on the passenger side fender of the carburetor. There should be 2 of them the rear most is for the EGR and the front one for the vacuum advance. The timing should not be 30 degrees so either the advance hose is somehow connected to the intake vacuum or the gauge is wrong or read wrong. Blow by shouldn't be that bad. Are you sure you have 180/185 PSI compression??? What's it like with the vacuum advance hose off??? Quote Share this post Link to post
MGTS 6 Report post Posted Wednesday at 10:08 PM The vacuum advance is not connected correctly. Is there a really good CA emissions diagram? I see a lot of T connectors in the lines Quote Share this post Link to post
datzenmike 37,270 Report post Posted Wednesday at 10:28 PM This is federal emissions but the vacuum advance is same Quote Share this post Link to post
MGTS 6 Report post Posted Wednesday at 10:49 PM Excellent. I need to get me a service manual. Nissan, Chilton, or Haynes? I really want a Nissan, but I am seeing them for $80-100 Quote Share this post Link to post
datzenmike 37,270 Report post Posted Wednesday at 11:14 PM Get only the '83 FSM (factory service manual) all others are 1/2 inch thick at best and cover multiple years and very generalized. The FSM is over and inch and only covers your year. Has EVERYTHING. $80 would be when they were new. Get a used one. $80????? you'll save that the first time you use it. What does a mechanic charge per hour??? Quote Share this post Link to post
MGTS 6 Report post Posted Thursday at 01:08 AM Ok got vacuum squared away and idle is stable. There is a thing on the back of the carb that pushes on the throttle linkage. It looks like there is a vacuum port on it but nothing is connected. What is it? Quote Share this post Link to post
datzenmike 37,270 Report post Posted Thursday at 01:33 AM Idle up solenoid, AKA the FICD (fast idle control device) When the air conditioner is turned on an electrical solenoid opens a valve allowing intake vacuum to the FICD which moves a plunger out and holds the throttle slightly open at idle. Quote Share this post Link to post
MGTS 6 Report post Posted Thursday at 01:50 AM Cool. I don't have AC. Sounds like I could remove it without affecting anything? 1 Quote Share this post Link to post
bottomwatcher 738 Report post Posted Thursday at 11:45 PM On 1/13/2021 at 5:49 PM, MGTS said: Excellent. I need to get me a service manual. Nissan, Chilton, or Haynes? I really want a Nissan, but I am seeing them for $80-100 https://www.nicoclub.com/service-manual This may not be exactly what you need but the are out there online for free 1 Quote Share this post Link to post
Charlie69 5,881 Report post Posted 22 hours ago You can find the Nissan Factory Service Manuals (FSM) used on ebay usually. Quote Share this post Link to post
MGTS 6 Report post Posted 20 hours ago Ok, I see that some vacuum hoses have little brass reducers inside them. Which ones? I don't trust the work that's been done by the previous owner 1 Quote Share this post Link to post
datzenmike 37,270 Report post Posted 20 hours ago The little reducers retard the vacuum action so a sudden but transient signal doesn't signal the emissions on or off too soon. The California emissions must be a nightmare. 1 Quote Share this post Link to post
MGTS 6 Report post Posted 20 hours ago Which hoses are they supposed to be in? 1 Quote Share this post Link to post
MGTS 6 Report post Posted 20 hours ago And when should I replace the timing chain/guides/tensioner? 1 Quote Share this post Link to post
datzenmike 37,270 Report post Posted 19 hours ago 1 hour ago, datzenmike said: The California emissions must be a nightmare. No idea, wouldn't even try to figure that out. I think the hoses have little paint splotches on them to identify. 1 hour ago, MGTS said: And when should I replace the timing chain/guides/tensioner? When it's worn out. I've never seen one wore out. The tension and slack side guides plus the tensioner are 'rubber'* coated. They wear out and are obvious. Owners seeing that just change everything. For chain/sprocket wear you move to the #3 hole but never seen anyone ever do this. Make sure it's from Japan. * not rubber but some hard plastic, maybe Teflon? Nylon? 1 Quote Share this post Link to post