Dave WM

I would just try them out, if you build the engine test stand you can get everything all hooked up, don't install, fire the injectors and know real fast how they will behave. If you want a little more effort some injector cleaner in a can and rig up a way to connect to the hose, fire it with a 9v battery. that way you will have a pretty good idea of the status with minimal hookup.

so those did not have a pintle cap at all or did you remove it? guessing removed since can't see the needle.

I have seen new style injectors sold as a replacement, IIRC something with 4 hole heads, short tails that have been modified to work with reg hose, and they are designed to not use the resistors to drop current flow due to different coils. sounds like a lot of differences from the recommended replacements. I wonder if the lower pressures would effect them as well?

so if you got a "pattern" it was prob just dirty interrupting the stream!!

agree with ZH on injectors, I would just test them see how they flow and if obvious problems then try picking the best of the litter. I did get mine prof cleaned locally, but you never really know what they actually did. Main thing is to avoid leakers or really poor spray. That being said the "spray pattern" is not all that great looking. Perhaps its the injector being dirty OR maybe just the lower pressure they operate at, compared to modern systems anyway. You could always just rig up a setup to spray cleaner both forward and reverse while triggering them. I think just using them by driving is the best way to clean assuming those filters are not clogged up.

starter is cheap just get one from a JY or autozone, always a good thing to keep in your spares bucket. for rad you can just plumb it for a straight thru water supply, put a hose on the inlet and let it free flow (keep the t stat out). It will never comp up to temp but you can at least hear it run and check for leaks etc... anyway you can rig the engine so its not going to fall sideways would do it, I used a saw horse configuration with the pan fitting in the middle, no real need to bolt down the engine, its not going anywhere. the starter can fit with just the thin steel plate that fits between the trans and engine, its plenty stout enough to hold the start in the correct position.

did you put together a test stand?

The idle problem is the BCDD, I think its supposed to act that way. below 10mph it disables (idle drops). Mine does the same, not a big deal. the design is trying to avoid high vacuum, lean run, high temp exhaust smog stuff. with out a computer and bunches of sensors it just does some crude things by todays standards to keep that from happing. At least that is my take on it from reading the FSM emission controls section.

the gasket is fine to reuse as long as you did not stick it down on both sides with some gasket adhesive and then have it get ripped up. I used some hi tack sealant on the cover side just to make it easy to install. When I remove the cover it stays on it, so when I replace the cover I just give it a visual and if no rips or other issue I goes back on. You will know if you have problems if you have a persistent leak on the rear side by the spark plug side, that is where the oil pools up. Just go easy on how tight you bolt back on. Best practice would be to replace it every time, I finally replaced mine after many cycles when it finally develop a very minor seepage on that back side.

some observations: Unused bullet connections seem to be the ones for the automatics per the FSM Unused white molded connector 2 piece, I think this is for optional head lights This one I cant figure out, its a Black wire with an eyelet, looks like a ground perhaps for the radio. Radio is working as is but maybe since the antenna is plugged in. Odd thing is its 60 ohms to ground? will double check that. I cant account for that. I think its a ground wire from the cable harness, I could not find a drawing of the "console harness" in my 75/76 FSM, the schematic did not show it, but did show a ground from the radio to the chassis. I would have to pull stuff apart to see exactly where that black wire eyelet comes from, I am presuming the cable harness and not the console itself.

So I am noticing my dash light were a bit bright, turned the dimmer no effect. (I don't mean excessive bright just bright enough for me to want to play with the dimmer). I don't know if this started AFTER the dash pull or not. I am pretty sure I check all the electrical (including the dimmer) after the dash pull, and all was well, but I am getting old so anything is possible... Anyway 1st order of bus was to look a the wiring of the dimmer, could I have somehow goof that. start by unplugging, no effect full power to instrument lights.. hmm.. So since the dimmer is just a variable ground, I figure the lights are getting a ground from somewhere they should not be. I suspect the radio will explain that I a min. I unplug the radio and now the dimmer working again (after I hook it back up). I plug the radio back in and disconnect the ground wire, radio plays, light work, not sure why disconnecting the ground does this but confident in my expert repair I move on. Next night happy to play with dimmer set it down some, driving around the block, suddenly instrument lights back to full. when I get home I look to the wire harness that supports the radio and center console lights, move it a smidge, lights toggle from dimmer to full on. So something is up with the wiring or what the wiring is hooked up to. I will double check to make sure the unused bullets (think its for the light in the ash tray or automatic) are not touching anything. If I some how got a ground connection on the lead that goes to the rheostat, I can see how that ground would cause everything to light up. Now back to the radio, back when I was working on it, I lost one of the small lights that illuminate the face. they are soldered onto a pcb. Maybe I did a poor job of soldering or left something off that blocks the light from the case, that's just a SWAG, but I can see it happening. 1st order of business will be to get a continuity tone to find when I get a short, seems the best place would be the ground side of that bullet connector for the aux light on the dash. with the dimmer fully CCW should be open to ground, if not then I can carefully move things around, starting with disconnecting the radio, that would get those pesky rice lamps out of the equation. If I unplug the radio and then can not recreate the fault by moving the wire harness around (I figure maybe its moving the radio as well), I will assume the radio is at fault. if unplugging the radio does not stop the intermittent ground then I will have to just get up close and personal with the harness to see if I can isolate the location of movement that is the most sensitive area and proceed from there.

with the EFI on the z car its about the details. Get ALL ground/connections clean and solid. this includes the connections at sensors and fuel injectors. Next you need to confirm no air leaks, I do this with smoke from a cigar after blocking off the TB. blow smoke into the brake booster port on the intake manifold. Confirm things like temp sensor resistance at the 36 pin connector, the FSM covers all this. All the above being said, since your car runs and all I can see is some white smoke from a freshly started car (not warmed up). I would suggest you make sure you have check the fuel lines (again NO LEAKS), get some oil in the trans, fix that bolt, and go drive it. running some gas thru the injectors will help clean up any varnish in there, and gas also is a good solvent for cleaning the entire top end of the engine as long as the air fuel mix is close. CARRY A FIRE EXTINGUSHER

if you are looking for things to do, make sure you have good hoses on all the FI stuff and use the correct FI clamps. Get FI rated hose, its a fairly low pressure system as far as FI goes, but why risk it. Also a trip to the local JY will give you a bunch of GOOD FI OE clamps, not those slotted style. You want a good tight no leak FI system, esp on a car this old that likely has leaks if everything has not been replaced already. Carry a good fire extinguisher at all times.

besides leaking oil, you may have an vacuum leak (the pcv assumes an air tight valve cover). a vacuum leak there will cause problems with the EFI system as unmetered air gets sucked into the manifold.

cant get the video to work, but with all that oil from the valve cover leaking down, I could see it smoking off a hot manifold.

the white tail pipe smoke is the issue? I thought it was leaking around the manifold? Take it out and drive it for a while, see if it still has white smoke. Are you losing antifreeze? is it overheating?

don't pull the head off unless its a problem. If you suspect a issue with the head gasket, start with checking for exhaust gases/oil in the radiator, and oil in the pan. If those are ok then leave the head alone. Typically I would expect an exhaust leak to present as a noise, and intake would be hard to notice unless it was pretty bad. You can smoke out intake leaks with a cigar and a hose after blocking the TB with a cup. IF there is a manifold leak its likely the exhaust on the back of the head. That is were one of the bolts typically breaks off, leaving #6 with just one bolt holding the manifold up tight to the head. After a while the hot exhaust will eat up the gasket and you will get a loud "tick" sound. You can find it easy with a 1/2" rubber hose hold one end to your ear, move the other end around the exhaust and listen for the tick. White smoke can be just something burning off, have you sprayed any chemicals around the engine? Here are a few things I like to do just to base line an engine, after its warmed up take a vacuum reading note the vacuum numbers as well as any erratic movement of the needle, do a compression test write the numbers down for future reference. Put in new plugs, drive it 10 miles pull them and take pictures for future reference.

smoke it out if you suspect an air leak. I had a missing injector o ring that cause issues, cant recall if it was like this.

also a good time for one of those see thru color tune plugs.

compression test on #6?

I can check the other bank, but I am pretty sure they are working, I can get it to idle fine (no missing) IF I manually deflect the AFM vane about 20 degrees. Once I open the throttle up, it runs normally (no manual deflection of the AFM required), so the problem seems to be isolated to low throttle or idle. I know the TPS is working since the other ECU works fine in the test stand. I maybe wrong on "runs normally at high throttle though, I did not run it very long that way, and as soon as I let off the throttle it backfired and blew the AFM completely off the throttle body.

I am going to try hooking up my AC analog simpson and see if I can get a voltage reading instead of just the lamp. will do with good and bad ECU. I recall disconnecting the temp sensor trying to get it to run, but I forgot to look a the light to see if was flashing brighter (FSM check for correct operation of ECU). If that is inconclusive (the simpson) I will get out the scope. That should give me some clarity on the signal for comparison. I will do this with the spare dizzy so I don't have to spin the engine over for testing.

oh and the 78 did NOT have an O2 sensor either. Guess that came on the later ZX. Again since all my pins "seem" to go somewhere I really don't know what I have in the way of an ECU.

Yea I read that, but visual inspection IIRC had traces to all the pins, all soldered and going somewhere (not just pads). I will be confirming that. I just read up on the alt comp, leans it 6%. Also if I read the 1978 FSM correct I should NOT have continuity between 12 and 9 for low alt (sea level). The wiring harness I have does not support a alt comp device so I presume "as is" there is no continuity, therefore should NOT be an issue. That and a 6% even if I am wrong does not seem to be enough to require such a large deflection of the AFM flap. I don't know how the signals are coupled to the circuit, I assume since the sensors are DC, then no capacitor issues, possible a resistor has gone out of spec, but without a schematic its like shooting in the dark. I don't want to go around probing with a multimeter set to resistance and end up frying a IC. Besides that the parts look to be high reliability so will have to stick with just a visual and look for an obvious defect. The fact that it works at all make me think its a base signal issue, the AFM flap effect it, the trigger is working. I suppose I should try it with the engine completely warmed up to see if the cold enrichments could be the problem (air/water/start). Still would not know how to effect a fix if one or more of those was the issue. IF its a base signal, IC2 seems responsible for setting that up, Not sure how the freq is derived, been a while since I messed with IC wave generators, IIRC I made some up as a kid from 556 and resistor/cap values.. CO HELP!!!! I don't even know if the IC's have marks on them, they are the round can types not DIP. If it had vacuum tubes I would be more comfortable....

will be digging in. for starters I am going to see if the 78 FSM has any mention of other sensors as well. I think that is the year that the ECU pins were all connected. I don't know for sure what year this ECU is from. I do know it has large alum guide ears on it if that is a clue.