MGTS 40 Posted January 13 Report Share Posted January 13 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 Link to post
datzenmike 38,531 Posted January 13 Report Share Posted January 13 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 Link to post
MGTS 40 Posted January 13 Author Report Share Posted January 13 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 Link to post
datzenmike 38,531 Posted January 13 Report Share Posted January 13 Don't mistake normal condensation (steamy exhaust) in cooler weather. Goes away when engine warms up. Quote Link to post
MGTS 40 Posted January 13 Author Report Share Posted January 13 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 Link to post
datzenmike 38,531 Posted January 13 Report Share Posted January 13 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 Link to post
MGTS 40 Posted January 13 Author Report Share Posted January 13 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 Link to post
datzenmike 38,531 Posted January 13 Report Share Posted January 13 This is federal emissions but the vacuum advance is same Quote Link to post
MGTS 40 Posted January 13 Author Report Share Posted January 13 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 Link to post
datzenmike 38,531 Posted January 13 Report Share Posted January 13 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 Link to post
MGTS 40 Posted January 14 Author Report Share Posted January 14 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 Link to post
datzenmike 38,531 Posted January 14 Report Share Posted January 14 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 Link to post
MGTS 40 Posted January 14 Author Report Share Posted January 14 Cool. I don't have AC. Sounds like I could remove it without affecting anything? 1 Quote Link to post
bottomwatcher 825 Posted January 14 Report Share Posted January 14 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 Link to post
Charlie69 5,983 Posted January 15 Report Share Posted January 15 You can find the Nissan Factory Service Manuals (FSM) used on ebay usually. Quote Link to post
MGTS 40 Posted January 15 Author Report Share Posted January 15 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 Link to post
datzenmike 38,531 Posted January 15 Report Share Posted January 15 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 Link to post
MGTS 40 Posted January 15 Author Report Share Posted January 15 Which hoses are they supposed to be in? 1 Quote Link to post
MGTS 40 Posted January 15 Author Report Share Posted January 15 And when should I replace the timing chain/guides/tensioner? 1 Quote Link to post
datzenmike 38,531 Posted January 15 Report Share Posted January 15 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 Link to post
MGTS 40 Posted January 16 Author Report Share Posted January 16 Carb overhaul time. What does this shaft to and how to I remove it? It twists just slightly and I've tried pulling it, but I won't come out. I don't want to pull too much lest I break something. 1 Quote Link to post
datzenmike 38,531 Posted January 16 Report Share Posted January 16 This is the ECC carb? I've never seen one as it primarily for California emissions. That there is probably the solenoid activated primary jet. It opens and closes electrically somewhat like a fuel injector. It's rate or duration controls how much fuel is drawn in and is controlled by the ECU under the seat with feedback from the O2 sensor. This keeps the fuel mix at the ideal stochiometric except idle and heavy load. 1 Quote Link to post
MGTS 40 Posted January 16 Author Report Share Posted January 16 I do not like this Sam-I-Am. Too many electronic parts for a carb. My Land Cruiser carb is much easier compared to this. Do you think it might be held in with O-rings? I don't want to damage, but it really needs to be cleaned I wonder if it's related to the running issues I had. When just rolling down to road with little throttle, if felt fine. When I tried to get up and move, it would lose a lot of power, but when I let off the throttle, I would get a sudden lurch and it would be fine again. Kinda like something was turning on and off. We will see of the rebuild helps with that 1 Quote Link to post
datzenmike 38,531 Posted January 17 Report Share Posted January 17 The ECC is a transitional carburetor to EFI. It's a traditional carburetor.... but has mixture adjustment capability and feedback from an O2 sensor. The ECU uses inputs and computes a mixture and corrects from the O2 feedback to keep the mixture tightly controlled. The inputs to the ECU are... Water temp sensor (not the gauge) Throttle switch (idle)* Engine RPM Full Throttle (vacuum switch) O2 sensor Neutral switch Clutch switch * the throttle valve switch is is on the carburetor I guess clean it as best you can. Bad running under power could be the secondary jet is partly blocked. Primary jet should be stamped (around) 95. Secondary jet around 165. Don't mix them up. 1 Quote Link to post
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