FastWoman

Well, 11-12 mpg is horrible mileage. You might get as low as 17 or 18 on a properly running engine if you're running it a bit hard. If you're going a tame 55 mph, you might get somewhere in the mid/high 20's. I get about 20 mpg combined city and highway with ordinary, non-heavy-footed driving. But no, these aren't the most fuel efficient vehicles!

^^^ I agree with Eric. Remember that just because you smell some gas out the exhaust doesn't mean the car is running rich. I don't know how old you are or whether you would remember cars that didn't have catalytic converters. Properly operating cats make our exhaust smell pretty tame. Without them, the exhaust will smell a bit gassy, even when everything is running perfectly -- with a perfect mixture. Go to any antique car show, and you'll smell a lot of stinky exhaust.

I went with whatever cap they gave me at the auto parts store. I don't know the brand. Seemd to work fine. Good fit. I know my injectors are Standard. There were a few rough spots on the molded electrical connector that I trimmed up, but otherwise everything seemed fine. Still working great. (I was able to get my car out a bit today, if only for a short errand.) I think 16.5 might be "good enough," but I'd want to be on the rich side of "good enough," rather than the lean side. I think after a while you can end up pitting your cylinder head and cooking your valves with a lean mix. I agree with Eric, BTW: The valves aren't scary. They're rather easy, and they're actually fun -- way easier than stuff you've already been doing. Enjoy!

... and I SHOULD have done that, but I cheaped out. The stainless allen head screws were $2 each. I just got hex-head stainless screws. In hindsight, the space is a bit tight to get a socket around the hex head. The allen head would have been perfect.

Be careful with those injector screws! A few of mine were frozen. The forward most one on the #1 WOULD NOT BUDGE, no matter what I tried on it, and it eventually broke off. I had to remove my intake manifold (which had to be done anyway, so no great loss) and take it to a machine shop to have that screw and a few other stubborn fasteners extracted. But be careful, because if you're not (and even maybe if you are), you'll end up with enough of your engine disassembled that it looks a bit scary. PBlaster and Kroil are great products for freeing up frozen bolts/screws. You might also try a miniature torch on the injector screws. I sort of wish I had tried that. You headlight issue might be a dirty/corroded switch -- assuming you've ruled out your connectors. You can open it up and clean it if you're careful. Don't bend the tabs too much. I've never done it, but I've been told...

In answer to one of your questions, the ECU has nothing to do with delivering spark. Rather, a signal off of the ignition feeds to the #1 ECU terminal and clocks the fuel injection. It's possible for an inoperable IM to result in an ECU not delivering fuel, but it's not possible for an inoperable ECU to result in loss of spark.

Any black interior plastic panels? I need both A-pillar panels for a '78. I could also use the little panels that attach under the dash on both sides. All of these panels are in pretty awful shape on my car. Thanks, Stephen!

Anthony, I'm guessing the car died when you hit at least the 2/3 point in the throttle. That's where the throttle position sensor would have signaled the ECU to deliver "full throttle enrichment." I suspect your problem is a mixture problem, and that's where you saw it. Maybe you're running too rich. I'm just guessing, of course. There could be any number of causes for having the wrong mixture.

It's hard to say, but if your battery will crank your engine after a full charge, I wouldn't replace it. There are numerous reasons your engine could be running poorly. You could have electrical problems, fuel delivery problems, EFI problems, vacuum leaks, timing issues. Unfortunately none of us would have a clue from the information provided. Time to break out the FSM, tools, meters and gauges! I'd start out by looking for vacuum leaks and a sticky/frozen breaker plate in your distributor. Most Z's on the road seem to have these problems.

You can certainly test your entire system for electrical conductivity with a multimeter, but you neeed to disconnect your radio first -- both the main fuse and the memory fuse. The reason is that it may have discharged capacitors and will otherwise have a baseline current draw that might mess up your measurements. But yes, check the polarity of the battery first. You can actually reverse charge them if not careful (although that's mostly a deep cycle battery issue). I bought a camper once that was running a reverse-charged battery. (RV color codes are weird, so I guess the PO got confused.)

Argneist, let's say your air temp sensor is off, so that it reads 68F when the temp is really 75F. That means your ECU will stop enriching the mix for temps of 75F and above. At some temperature point, the air temp sensor will tell the ECU, correctly or incorrectly, that the temp is 68F. That's where the ECU will stop enriching for air temperature. (It may still apply enrichments for other factors like coolant temp.) Eric, I had forgotten about those line graphs. Eyeballing the upper graph on EF10, it would appear that my fuel output was about 75% of what it should have been. When I boosted it by 33%, my mix was correct. I guess that coincides roughly with the experiments I had been doing with fuel pressure.

Well, EXTREME lean running can foul plugs from engine misfiring. I can attest to that from personal experience. However, the goop component might be something else. I think you might be burning oil in those cylinders. But you never know until you work through all the problems systematically. Even if you end up rebuilding your engine, you'll still need your fuel/intake working correctly, so nothing you're doing is wasted.

Eric is saying that the temp sensor tells the ECU the temp of the intake air, and the ECU richens the mix accordingly. At 68F and above, the ECU doesn't richen the mix. At 67F, the ECU starts to richen the mix. As temperature drops, it richens it even more -- the lower the temp, the richer the mix.

Yeah, that would definitely be a lean-running issue! You can get the small dia vacuum line and smaller diameters of fuel line from your local auto parts store. Larger fuel-rated lines can be found at your nearest tractor supply, or you can call Hampton Rubber in Hampton, VA. If you ask them very nicely, they might mail-order you what you need. (They have EVERYTHING rubber in the known universe.) You'll want fuel-rated hose for the hoses to the air regulator and from the valve cover vent. Don't use heater hose.

Well, before you replace injectors, you should make certain you need to. I only guessed at your problem, but without putting a gauge on your fuel rail, it's only a guess. Besides, a leakdown problem could be the check valve too. Although those are becoming NLA, you can buy an inline fuel check valve off of Ebay that will do the job.

Tomo, it's not as simple as that. The ECU can drift over time. At least that's what Cozye and I have found. We both got EVERYTHING in our systems to spec, and the mix would still be off. We both had to richen our mixes quite a lot to get our engines running well. The idea of a wideband sensor is appealing. It might be something useful to stick in one of those gauge pod pillar thingies.

Dunno... I use B6ES-11 in my '78 (per specs) and also use the NGK inductive wires. I used the same combo on my old '75, for a combined total of 15 years of daily driving. I never had any problems. The most noise-critical component in both cars would have been the stereo. Yes, if I turn up the volume high enough on my current stereo, I can hear a tiny bit of noise, but only if I strain my ears. It's not at all objectionable. On my '75 (which had a cheaper, poor-student-variety stereo), I did have a bit of noise, but I simply installed a choke on the +12 wire, and the problem went away. Your ears will tell you whether there's a problem. Our ECUs are quite primitive and are linear devices. They won't go crazy from electrical noise like the digital ones could.

Well, being drained is pretty hard on a battery and does sock some of the life out of it, but as long as you can start your engine, that's all you really need of the battery. Anyway, glad you got the problem tracked down!

Tomo, I'd say the WD-40 works as a light-weight contact cleaner. It's not as good as Deoxit, but it's really not half bad. I like that it leaves a light, protective residue. I've never had it damage or gum up anything. I wouldn't sweat the fuses. If you see corrosion on one, yeah, toss it. Also toss it if it doesn't test good with a meter. Otherwise, no worries. I routinely use a lot of fuses a lot more than 33 years old. I think I've only seen one or two fuses fail from metal fatigue or corrosion (appearing to be good, but actually being open). Just carry some spares in the glove box, and if one blows, you'll be prepared.

From the profile, it's a 1978, so there's no external voltage regulator to replace. Perhaps the shop opened up the alternator to replace the regulator circuitry inside? An output of 13.5V is a bit on the low side, but I think acceptable. It should certainly keep the battery charged and your engine running. Even 12.7V at the battery should keep your engine running. You say you "suddenly" lost electricity. Did the engine run poorly before that, or did it just die -- BAM? If it suddenly died (BAM), then I would suspect a bad connection somewhere. Probably a fusible link. You might also check the integrity of the white accessory wire off the (+) post of the battery. It can get corroded just under the insulation. Your voltage problem (which would be different) might be due to crusty wiring between the alternator and the fusible links and from there to the battery. With the engine running, see if there's an appreciable voltage drop between the alternator post and the corresponding fusible link. (I forget which one it is.) This circuit was poorly designed in the first place (wiring gauge too small, and 2 or 3 crimp connections en route to the battery). You can start unwrapping the wiring tree from the alternator back towards the fusible links, and pull out/replace the main wire from the alternator to the fusible link block. That might help. Of course your alternator might put out sufficient voltage but anemic current. You can have it tested at many auto parts stores if you want a second opinion (apart from the mechanic's).

Herb, FAIW, a metric allen-head bolt might be better. Casual thieves might have a couple of pairs of pliers on hand, and maybe a wrench or two, but I bet not many carry metric allen wrench sets.

Nice, Eric! I'm impressed...

What Andrew and Zed said. I forgot about the relays. There's a black box on the passenger side of the engine comparment, mounted to the inside of the fender. There's a plastic cover inserted into the backside of it and a few screws securing the cover. Remove the cover, and look inside. You'll see several relays there. You can pull the connectors off and clean them up. I can't draw on too much experience here, but I THINK ECU failure is rather rare. Ztrain documents some cold solder joints in his that he had to re-flow, but I think his engine still ran. I've never heard of one flat-out going kapoot. I think may be rather common for them to fade away, but the engine should still run at some level. That said, I think fuel pump control is powered straight off of the ignition circuit, once the engine is running. I don't think the ECU is involved in any way except for sending the original 5 sec "start" signal. The fuel pump should keep running as long as the engine is running (assuming working alternator and oil pressure), irrespective of the status of the ECU. I agree with Andrew! Kudos for toughing it out. Once you get it running right, it will be a very reliable machine -- along the "use it or lose it" lines, of course.

Yeah, be gentle. Carbon isn't that big an issue. Oddly, carb cleaner can attack an adhesive used to seal the waffle side to the rest of the body (and might also attack a rotted O-ring around the idle mix screw). It doesn't attack the sealer TOO quickly, but does make it a bit of a gooey mess. I found that brake cleaner doesn't attack anything on the AFM but the dirt. I haven't tried throttle body cleaners. Squirt some oil around the shaft when you're finished.

I'm not fond of Holleys either. The model number should be stamped on the air horn. You can order a rebuild kit if you need one for about $50 (local auto parts store). I'm not understanding why you need to jump-start because of a bad choke, unless you just keep cranking until the battery dies. Try stomping on the accelerator a few times before starting -- assuming your accelerator pump works. That should kick it over. Whether it keeps running is maybe another matter.