MH77280Z

What is the cold start idle RPM range? I think normal engine temp idle rpm range is 700to900?

Hi Friends, Sometimes when i turn the ignition On-Start etc. the starter do not engage. It is like there is no current flowing to it. I then back off the key and turn it ON again and after 2 try or sometimes 3rd try the starter gets engaged. Mine is a A/T so there is a seat belt relay which is also involved and I have the seat belt hooked. Have anyone seen this? where can the issue be? I feel one of the relays is not getting energized? what you guys think? Starter is rebuilt and I am hoping it is not a starter/solenoid issue.

So today I took the AUX AIR Regulator off and inspected at cold, it was closed. I then bypassed the regulator and connected the hose directly into throttle chamber and the car fired up much better and no sputtering. Idle was fast though. I shut it down. Plan to get this rebuild from fuel injection corp and test it again and adjust the idle speed. Will report back in about 1 week. Really appreciate you guys hangin in there with me. There is one more question: I plan to change some of the vacuum lines coming from the vacuum reservoir. 1. There is one thin vac line going into the firewall next to the battery, where does that go? 2. Also, in front of the fusible links towards the car front there are two round switches, vacuum lines also go into those. What are those?

Guys, when i bought the car i took a risk. I knew it was overheated and also later found the head cracked. So far we have replaced the head and car seems to run decent. Took these compression readings last week and wanted to share. Cylinder 1: 130 Cylinder 2: 130 Cylinder 3: 135 Cylinder 4: 140 Cylinder 5: 130 Cylinder 6: 130 I have yet to see if it burns any oil. Not driven too much. But i expect older engine to burn a bit which is fine. I change every year and dont drive too much. What do you guys think about these numbers? Personally i expected a bit worse but I think 130+ should be acceptable? Any advises for on-going maintenance are appreciated as well?

What is IAC? I have a feel it runs a bit lean at cold. The cold start valve is brand new and so does the connector to it.

Hi Friends, Clean gas tank, new bench tested injectors, all new injector connectors, also changed connectors to themo time, temp sensor, cold start valve is new and so is the harness connector. The car runs well after it warms up in 1-2 mins of idle. Cold start is giving me issues, the engine sputter and try to die. If you pump the gas it is uneven, sometimes it suddenly jumps to very high rpm, i mean u really have to keep pumping the paddle to get it running. We are thinking AFM? TPS? or anything else? any experiences you can share?

Hi, I was bench testing an AFM. I get around 225ohm between 6 & 8 and 125ohm between 8 & 9. Has anyone seen this? does it mean it is too much and it requires cleaning and re-calibration? https://www.atlanticz.ca/zclub/techtips/afm/index.html Measure the resistance from the high side to the low side of the pot/copper trace. (Pins 8 and 6). It should read ~180ohm Measure the resistance across the "standard"/"Reference"/"Control" resistor. (Pins 8 and 9). It should read 100ohms

I have decided to go with 10W-40. I have used it in my 69 Cadillac with a 472 block and flat cams and it has given me great results last 7 years. https://drivenracingoil.com/i-30497806-hr5-10w-40-conventional-hot-rod-oil.html

10W-40 is good choice too. I was just going by what was listed in the manual attached. Temp in CA varies quite a lot Winter below 50 and Summer 75+ I have not come across anyone who uses 10W-50 or 20W-50 though as mentioned here in the manual.

The oil pressure is good. It drops below 1/3 at idle but then climbs up while running. I do expect some oil burn though as i do need a engine rebuild. But for now I want to run the car for sometime to get everything else figured out. 10W-40 is also a good option. What were u thinking?

Guys, I am debating between 20W-40 and 20W-50. The weather in CA does get in the 90s in Summer but in colder winter it does come down in the 40-50 range. Right now I am at 20W-40. Let me know what you guys use. Also any good brand in the 20W-40 range with good dose of ZDDP?

Thanks! Paid a bit more close attention this time. It was beeping as intended without the seat belt. With the seat belt it did cranks nicely. Relay turned up fine i think. I started cold so it did gave me some problems at the start. I am changing the temp/thermo time/cold start valve connectors as they are all loose and broken next. Test out the cold start injector on the machine and finally its time to change the thermal coupler on the fan.

Thanks for the tip. Seems like something not to be rushed especially if the engine is running ok. Let me air blow it first and use dry brush to clean areas along with damp cloth like others are suggesting. I am applying new silicon to places like AFM circuit cover etc. Just curious i have hosed and pressure washed my other more latest 2000+ model cars with no issues. Are we just more cautious with the 280z due to its age or something else?

Thanks!

Guys, i bought a 77 Auto over a year ago and car was sitting for 3-5 years. It does need a wash!!! I stumbled upon somewhere in the manual that says do not steam clean the engine. Is anyone aware of this? I am not able to find that again. Right now I am just planning to use some good of the shelf solvent and wash normally. Is there something I need to be careful about and prevent water to it? Appreciate some input.

Where is this relay located?

Hmmm - yes sir we have not hooked the seat belt!!! but I can try that tomorrow and report back.

Hi Guys, I posted a year ago that I bough a Auto 280z and finally I had it running. Had to do quite a lot of work and it still need more tuning but I was able to get it running on road. The problem is starter voltage !!! I have the new Nissan OEM fusible links installed as well. When you turn the ignition sometimes the starter does not get engaged and if it does it does not get full voltage. We have to use a remote starter button and directly supply voltage to the starter and it then cranks up nicely. The battery is brand new. Can someone guide me what to check between ignition and starter? I would assume there is somewhere a relay also involved.

Thanks all - really helpful. Expect more questions as I am trying to get my 77 Auto tuned. Appreciate all the patience as well 🙂 Right now waiting for new ELBOW and fusible links to arrive from Courtsy Nissan.

The rubber elbow between AFM and Throttle body in my car has a port as well. Your pic above does not show that which is what I am trying to figure out. Chk the T connection on the pic I downloaded below with labels in yellow. This has the T blocked at one end. Now the rocker/valve cover ports in this pic connects to the rubber elbow port. And the T connection on the air regulator inlet is taking input from throttle body etc. And while the 77 Manual pic I have connects the valve cover port directly into the port at the regulator which is blocked on my car and also shown blocked on the eficonnection JPEG. Just makes me confuse because the valve cover hose is venting vapors back into the throttle body via the opening in the elbow. So I believe the flow is from rocker to elbow and the T can connect directly to the opening on the throttle body I believe. So I think first EFI jpeg seems correct?

Hi, I want to confirm the connections to the air regulator etc. The intake side of the regulator has a T. One side obviously goes to the air regulator. On my car one side of the T is blocked with a HOSE/Clamp. My question is, the 3rd side of the T connects to the opening on the rubber elbow between AFM and throttle chamber? Also, where does the connector on the rocker/valve cover connects into? does that go on to the throttle chamber port?

Found some additional info here for fusible links below. Let me get the correct ones and try again if that changes anything. But I am sure those links were custom made wires etc.

Yes mine is automatic. Looking at your diagram, seems like the two fusible links are in the electrical path. We probably changed one or both of these links and made it with a wire in the shop etc. Should i get something from ebay which is close to OEM? what is the guidance on these two links if they need to be replaced?

We did install a new oil pressure sender. Let me check the cam lobes today when we start the car. I think last time when installing a new cam we did a remote start with the valve cover off and did see the oil coming out of the cam holes. Mine doesn’t have a spray bar etc. but will verify again.

Friends, I need some insight what to look for here. Engine oil in the car is Valvoline 20w-50. The oil pressure when the car starts is decent but then as the car warms up the oil pressure goes down. I know it is a bit open question but what should i look for? is there a good starting point? is there a way to test the oil pump? or oil pressure at a specific spot etc.? Appreciate some help ...