TieFighter88

Epiphany : This issue could have been caused by my previous problem I posted here, which turned out to be caused by my previous owners retarded Distributor orientation. Detonation did occur *once* with the incorrect spark plug wiring sequence, this would certainly blow the gasket ? Was a very good bang, and it came out the rear end rather than back out the intake... Will pull the head off when I get back in town, I love these engines, so easy to work with.

Still reads maximum when I ground the connector also... will follow the wiring through the dash...

Broke the lower thermostat housing whilst tightening at the thermal transmitter, didn't take much at all... After disconnecting all of the wiring from the thermostat housing, the temp gauge still gets a reading from something...still Maxed out...

from "http://www.zcar.com/70-83_tech_discussion_forum/where_is_temp_sensor_81_280zx_644149.0.html" The following is for a 79, the location of the sensors may be different for an 81 but the description of what they do is correct Looking at the motor from the front, the thermostat housing has the following items: At 2:00 o'clock the "Water Temperature Sensing Switch". It controls the fan which blows air towards the injectors / intake manifold when the coolant temperature is above 110C. It has a single wire connected to it with a "male" bullet connector at the end of the wire. (it is usually green and about 2" long) At 4:00 o'clock the "Water Temperature Sensor". It is connected to the ECU and provides coolant temperature readings in the form of a change in resistance. As the coolant temperature increases the resistance decreases. This sensor works in conjunction with the "Air Temperature Sensor" in the AFM and is also connected to the ECU. These two sensors provide input to the ECU so that the ECU can change the fuel injector pulse width. At 8:00 o'clock the "Thermotime Switch". It is connected to the "Cold Start Valve". At 10:00 o'clock the "Thermal Transmitter". It is connected to the Temperature Gauge in the Dash. It has a single "male" bullet connector built into the end of the sensor. Wayne Monteath Masham, Quebec.

Thermo Housing is that of a 280zx

Been searching through my service manual and I cant locate a diagram ... L28 F54 Block N42 Head, discovered that the block is from a (1981-1983) 280zx, so will check out the 280zx service manual then... Yet the Head is from the 75-76 280z... will check out that manual also then...

I thought about that also... but after seeing the bubbles in the radiator today I got nervous, and my temperature indicator isn't working right, so I just pushed her back into the garage...

The temperature gauge in my dash just reads maximum when I turn the ignition on, and whilst I have the engine running... Retracing and repairing the wiring throughout the engine... I found after tracing the wiring harness has a pair of wires snipped and free without a connection, they are both green and were taped with the wires that run to the thermotime switch. Can somebody please identify the components of the thermostat housing in the photo I uploaded? Off the top of my head, 1: ? 2: ? 3: Water temp sensor 4: Thermotime Switch

78 Datsun 280z , L28 F54 Block N42 Head Trying to identify the cause of this thin white smoke. I cannot see exactly where it is coming from and I cannot identify the whether is an odor of burnt oil or coolant. Before I put the valve cover back on, I put a lip of oil with my finger on the gasket , not a good thing? Thin white smoke is coming out of somewhere now, bubbles are entering the radiator when I rev the engine, so I figure it is the head gasket, but could it also be caused from up on the valve cover 2? Could it be the oil on the valve gasket burning? I dont think the Valve cover is that tight down either, I felt 2 of the 10mm bolts around the cover strip out, I barely got to tighten them much... what should I replace them with? This smoke is immediate from a cold start also, well before the engine is at temperature... so I don't think it is just gunk burning around the engine / headers...

Bubbles in the radiator, blown head gasket...

SOLVED - Incorrect Distributor Orientation: counter-clock 153624 sequence starts at 2 o'Clock, rather than from the original marked notch on the cap / FSM stock configuration starting from 10 o'clock... I removed the Rocker cover and plugs so I could physically observe the valves whilst establishing TDC / monitoring the each of the pistons compression cycles. Felt the compression from each piston and confirmed the correct 153624 cycle and mapped it on the distributor, which was mounted in a fashion fit to this retard that put her together... Pushing the whole car in 3rd gear up and down the driveway, I don't have the 27mm socket for the crank... great workout. Will tune her up tomorrow, not everybody in the neighborhood shares my enthusiasm for this car at this time of the morning... Did notice smoke from somewhere in the bay though, I couldn't discern if it was oil or water... was immediate from this cold start, could just be gunk cooking from the outside of the block / headers or a bad gasket... but will pursue this issue in a separate thread as it shouldn't be related to what we have been chasing in this one. !!!THANK YOU VERY MUCH !!! EXCELLENT INPUT MATES!!!

Still the L28 in the 82 280zx , so it should be the same. Will definitely check the timing and the distributor tomorrow. I hope it is obnoxiously out of sync, almost exhausted every option to check...

I checked out and cleaned up the Ignition transistor, the FSM says there isn't really a way to test it; like the ECU "just replace with another unit"... I have a spare ECU that came with the car and I swap them out with each attempt to see if the ECU is the issue... I was happy to find that the Ignition Relay is the new one, Nissan released a different pair of relays to supersede the factory original (had a faulty ground or something)...

Visibly confirmed spark from each plug, consistent and not erratic. I have cleaned all the pickups and checked out the distributor and freshened up the spark plug wires... The ignition timing must be off, but I have attempted to start with every possible timing setting on the distributor... The fuse box has a splice to the AC fuse, and one to the Fuel Gauge fuse. The center console has switches to power the fan/AC compressor ... And the FUel Gauge works fine... Although these wires could lead somewhere else... worst wiring cluster dance I have ever experienced...

Just tried putting a 5ml shot of oil into each cylinder to up the compression, felt like she had more kick and a soft putter. I adjusted the timing on the distributor just slightly with each attempt and could only flirt with the engine starting. Sounds so close. The injectors are definitely squirting, the plugs were filmed up in gas when I pulled them. Will let her sit for a while tonight while I rip up the rest of the wiring in the interior. I open the AFM and squirt starting fluid in there, to sit between the AFM valve and the throttle chamber and it just ignites and pops back out ... :0 Found two random wires spliced into the fuse box, will follow them back to see what this idiot has wired them to... please see below. (how do I post an image on this forum?) only allows me to add a weblink...

Apparently she ran great, but again this is just from a dude on craigslist. He took my offer of 1000, I knew it was a gamble so I didn't offer any more. Plenty of bling throughout the car otherwise, so shouldn't be too burned if the L28 is dead... After seeing the really poor wiring job I have to pursue all the harnesses and relays first, as they need love regardless if the L28 is running. Will get into more mechanics after I finish ripping up all the electrical tap hiding these finger twist splices... More and more life in the electronics as I clean up the wiring one step at a time, only the dash lights/turning signals and radio are out that I can see now...

Thank you very much for all the help mates, giving me more confidence in this car and glad I found a good community online for this!

I did experiment with the timing, I have it set all the way to the bottom, this caused the most life in the engine while attempting to start... The firing order I have wired up is according to the typical L28 1-5-3-6-2-4 counter clockwise... All the spark plug wires are good and sparking consistently... Triple checked for air leaks... First thing I eliminated after I could hear the backfiring. I put a good 5ml squirt of mystery oil in each cylinder to sit overnight when I first tried to wake her up after the 2 year sleep... will add more oil and try again, the oil pressure gauge inside is moving but on the low end... although the dip stick reads full... I did consider to pull off the rail and check to see if the injectors were actually squirting, I already serviced them tho and they are clicking nicely... will triple check from the rail tho... Will rip the carpet up tomorrow and finalize the rest of the wiring before I start crying to the guys in Holly Hill, I know it has to be some simple electrical issue...

I see you are in Orlando? Do you know of anybody that is a Datsun guru in the area? I am in Port Orange by Daytona.

yep, full mouth full of starting fluid, just makes backfiring more violent and loud. AFM is clean and connectors are all good and checked. I was worried that it was impeding the air flow to the throttle chamber. I can see it barely moves past half way open when attempting to start. I open the AFM myself and spray the starter fluid in there and when it ignited it just came back out from the intake... so stumped...

Bought a 78 280z from a dude for 1000, fresh L28 engine in there apparently... she had been sitting for almost 2 years and now I am trying to get the engine started. I replaced all of the fluids and serviced pretty much everything: Oil, radiator, fuel pump/lines, air hoses, electrical connections, injectors, relays, fresh battery, plugs... Just wont start; dull backfiring when I turn it over... I have spark on all the plugs, the distributor is fine, injectors are fine, fuel pump is fine, fuel pressure is fine, fuel relays are fine, ignition relay is new. The ECU harness satisfies all the tests from the service manual, I checked the whole harness for bad connections and she is clean now. Tried 2 different ECU units... Still inspecting the accessory harness, the only symptoms I am conscious of now are: No dash lights (except the map light) the engine temperature gauge reads maxed the radio doesn't work now All the fuses are ok ... I am totally confused... are their any common simple checks that I am missing? This EFI is killing me... still working through the EFI bible also...