govtcontact

A quick review of issues while the Z worked.

• Ran
• Smokey Exhaust
• Oil under the hood from some place
• Started very easily

Did a compression test. Compression ranged from 60 - 80 psi (dry), 70 - 95 (wet).

Tried to correct the timing for chain stretch...Chain tensioner popped out . Pulled the front half of the engine compartment so I could access the front timing cover.

Town evacuated for over a week due to massive fire.

Replaced timing components. Broke valve, damaged piston. . Replaced piston and valve. Did a ring job, new rod bearings, new distributor, new gaskets, new valve stem seals, lapped valves, cleaned off carbon, cleaned varnish from old gas out of the intake runners, repaired groove worn into front timing cover from when the crank pulley separated and cut through on the previous owner, assembled new wiring harness for engine sensors and injectors (using the newer Bosch Style 2).

Rod bearing clearance : <= 0.004"
Ring Gap: 0.049 - 0.059 (old rings), 0.024 - 0.029 (new rings)
Timing chain (new) installed onto #2 on cam sprocket

Tried starting motor. Cranked over, squirted fuel and sparked.

Completed all Ohm and Voltage checks in the 1980 Z Fuel Injection bible. All passed except the throttle position switch. Also noticed the wires attached to the condensor look ragged and only 1 or 2 strands of wire are still connected.

Now the questions:

1. How do you prime the oil pump/system
2. What are some of the common gotcha's with these cars?
3. In testing spark on an external plug, why would there be spark for the first few rotations, then none?

I tried to cover the main points that I felt might be reliant out of the 40 some odd pages of notes taken in my log book.

NismoPick

Yikes...

How did you know the timing chain had stretched? I ask because it's UBER rare for these double wide chains to actually stretch, even though Nissan made 3 slots on the cam gear just in case. Maybe if the motor had 300k+ miles? But since the compression was so low, I guess it's good that you rebuilt it.

As for the oil pump prime, click: https://www.zdriver.com/forums/showt...ime#post280013

Hopefully you're doing the rebuild w/ an FSM or Haynes manual in hand (which has all the info about timing & priming).

And as for the no start, I suggest re-checking your timing. I wager a guess that the distributor shaft was mis-aligned upon install (IF there really is proper spark & fuel).

govtcontact

Thanks for the link. Unknowingly I did fill the pump with oil. On my MOPAR, you turn the distributor drive shaft to pump oil through the system.

I didn't know if the timing chain had really stretched, but wanted to rule it out for the low compression (read a post someplace that out of wack timing could give low compression numbers). There was major wear on the chain guides. In fact one was almost worn down to the metal.

I will double check the timing now that I got some sleep, but I really dont like the spark quality.

govtcontact

Okay...Checked the timing...It was off. At TDC on the crank (#1 TDC), cam lobe #1 was at 3 o'clock when looking from the front.

I do not feel comfortable even attempting to start the engine until I get some conformation on the cam position. With #1 piston at TDC, what postion is the #1 cam lobe at when looking from the front...Is it at 12 o'clock?

The reason I ask is that this is what bit me in the butt before and led to replacing a valve and piston.

NismoPick

All that info is in the Haynes / FSM. If you don't have the FSM, I suggest downloading it from www.xenons130.com/reference.

This is a scan from the Haynes manual. At TDC on cyl #1, the cam gear will be here:

govtcontact

NismoPick: Thank you for the pictures/post...Those images are by far better quality than the pdf's I was using, which I downloaded months ago from that link. (No shadow images/text from another page).

I guess the coffee finally kicked in because I realized who cares where the lobes are, what is wanted is where the cam marker notch and the groove in the sprocket are in relation to each other.

As far as the spark goes, I repaired the condensor (repaired the wire that was only connected by 1 strand of wire), and then installed a coil that I know throws a hot spark, (stole it off of my 2.2l Turbo-Mopar).

I turned the key, it fired up...Heard a thunk! (WTF!) Oh yea, forgot to remove the socket wrench off of the crank bolt from when I set the engine at TDC).

But the kid is now sleeping, it works, so I guess its time to put the exhaust on and put it all back together.

Thank you all for your help!!! I knew I had to be doing something stupid and just needed a smack across the face.

govtcontact

Okay...I set/verified the cam/dizzy/#1 cylinder are where they were suppose to be. It fired up. While letting it warm up to so I could set the timing, new issues arose.

1. On the thermostat housing I have the Thermo-Time sensor. Above that is a temp sensor where a wire with a plug connects to. To the right of that, there is another sensor that once had a wire coming out of it*. Below that is another sensor that looks like the thermo time sensor*.

First few questions:
-What is the sensor called that should have a wire coming out of it so I can get it replaced?
- The sensor in the bottom right (looking from the front), is this the head temp sensor? Before replacing the connector for this sensor, I jiggled the wire and the engine died. No she dont want to start.

Issue #2:

Now to even get the car to start, I have to pull the Fuel Pump Relay, crank the engine over. When it starts, hurry and plug back in the relay and give a bit of throttle to try and keep it running. The cold start valve is disconnected. All injectors were pulled, cleaned in an ultrasonic bath, tested they did not leak, and verified they worked.

-What would be some possible causes of to much fuel being injected?

FricFrac

Check EL-46 in the 1983 FSM that NismoPick linked to above

WildmaN

The only thing that sucks with the manuals. Is they don't tell you how many links from the top hole on the camshaft sprocket. To the bottom hole on the crankshaft sprocket. So my brother and I counted the chain links on my other engine I had lying around. And it was 22 links from the top hole to the bottom hole. Which is permanently written in my Haynes manual. And man, what a nightmare that was, trying to align everything.

NismoPick

^^^ The crappy issue w/ aftermarket chains... no colored / shiny links.

govtcontact

My aftermarket chain had 2 shiny/silver links. It was the cam sprocket that was useless...It had no 'V' or 'U' notches on the backside to line up to the cam retaining plate. But all the parts were "Made in Japan" and picked up the full set for ~$60 from RockAuto. (Its not under the Timing Set complete, I think its under the Timing Sprockets and it was ~$30 cheaper than anything listed in the Timing set Complete)