FastWoman

10mm = approx. 3/8 intake 8mm = approx. 5/16 going forward. The noise might be from your having damaged/bent/misaligned the fuel pump's rubber bushing system, so that you have metal-to-metal contact. Just a guess.

Oh, I misunderstood! Never mind. I thought you had the same plugs as when you put the car to bed many years ago. So you should pull and read them now! Do you know what to look for? Can you post a photo?

Kelly, you need to install a fresh set of plugs, so that you can see how the individual cylinders are running. If any of your injectors are partially clogged, the corresponding plugs will show lean, while the others show normal, less lean, rich, whatever. If you have a completely clogged injector, the plug will look brand new. The other way you can check the health of your fuel rail is to pull it and spray fuel into little glasses with it, essentially flow-testing it. However, that's pretty labor intensive.

I agree. I have a low pressure filter on the intake of my pump as well. No problems so far. The next time I replace it, I might use a clear, polycarbonate filter, so that I can see any debris. Something like this: Spectre/Clearview replaceable fuel filter (6932) | Performance Fuel Filter | AutoZone.com I installed that filter on our 318 inboard boat (which would suck down fuel like a Russian sailor would swill vodka) and had no starvation issues. It's not a particularly fine filter (speaking in terms of particulate size), but it would catch any larger junk that would do damage to the pump, and it should be pretty free-flowing. I've also used this same filter for many years on my tractor. Your pump noise MIGHT be due to a missing or malfunctioning fuel damper. The purpose of the damper is to reduce fuel pump noise. Also check that your pump is supported with rubber and is not mounted metal-to-metal. Ordinarily the pump makes a tiny whine. You can hear it, but not very easily. The random nature of the stumbling suggests to me that you might have dirt in the fuel rail / injectors. Of course it wouldn't distribute itself uniformly if that's the case. How do your plugs read? Do they all look the same? Different? Hose sizes: The two supply sizes are 5/16" and 3/8". (OK, those aren't metric sizes, but they're close enough.) As I recall, it's 3/8 from the tank to the pump and then 5/16 thereafter, but you'll want to confirm that before buying hose. If you end up getting into the bigger project of replacing your fuel vent lines, then you've got some bigger sizes there. I believe the biggest is 5/8". Resist the temptation to buy heater hose. You'll need fuel-rated hose. You can get that size of fuel hose from a tractor supply and also from Hampton Rubber in Hampton, VA. (You'll have to call them and put together an order.) Your stubborn screw: DON'T DO THIS IF YOU HAVE ANY FUEL IN THE AREA: You can always use a dremel tool to make a slot that a flat-blade screwdriver might like. Use a low speed, and don't make sparks. Take your time. If the screw still won't turn, maybe you can cut off the head, remove the part, and turn the screw shank out with some tiny (and new/sharp) vice grips. I've gotten in the habit of replacing all of my screws with stainless, by attrition. I think I ordered some stainless metric assortments from BoltDepot.com -- like this one: Metric assortments, Small plastic compartment boxes, Metric Bolt Assortments, Stainless steel, Metric hex bolts (coarse thread) w/ nuts, flat washers, and lock washers 6mm - 10mm - Bolt Depot Also buy some antiseize lubricant. You'll want the nickel variety for putting stainless into aluminum, and any variety will work for stainless into steel. Be careful, though, because a well lubricated stainless screw can back out.

I think it sounds like an extreme lean condition. If you pull off the vacuum line to the fuel pressure regulator and block the little hose with your finger, does your engine still backfire when you hit the throttle?

But isn't an AZ alternator a rebuilt OEM? Not rebuilt well, maybe, but it still has the same copper windings and such, right? FAIW, I replaced a GM alternator on our boat (Chrysler 318 inboard engine with a reversed bracket for the alternator, so that it would spin the right direction) with a rebuilt unit from Advance Auto. It was $35 with exchange, which both delighted me and caused me considerable apprehension. That alternator held up under the most hostile imaginable service (salt air environment with heavy condensation every night) for 5 years until I sold the boat. So it wasn't a bad rebuild at all. Ah, therein lies the rub. While I agree with you, photography, web design, and graphic design aren't exactly booming fields. Pay is good when I can get it, but in all honesty, I have way too much free time to replace Chinese crap. So the better question (for me) is how much frustration is a part worth. In all honesty, I thought the Saturn radiator was a 30 min or 1 hr R&R, based on what I read on the Saturn boards. However, what I read was wrong. The biggest headache is that the AC condenser coil is mounted directly to the radiator, the two cannot be removed together without disconnecting freon lines, and there is almost no room to get to the condenser coil mounting screws. Uncharacteristically BAD design for that company! Anyway, it's about a 2-3 hr R&R, and I would have gone with a non-AZ part considering. I think I'll be buying more NAPA regardless. BTW, I'd reconsider those HF jack stands, Wade! I had a weld break loose on an old Chinese jack stand, not that it dropped a car or anything. Chinese might generally be fine for this item, but HF sells the bottom rung of Chinese goods.

A precautionary rant: I've been a proponent of lifetime-warranted AutoZone parts, provided they are easy enough to change out. The alternator in my '78 280 is a good example. The swap is fast. I'm on my 3rd AZ alternator now, but it was cheap and easy. I'm really starting to question the wisdom of this plan, though. My Saturn's radiator tank cracked, so I got an AZ lifetime warranted radiator. After changing out the radiator (very cheaply constructed in China), I was STILL losing fluid at about the same rate, but I never could find a leak in the driveway. It turns out the radiator had a drain plug whose threading was slightly too small for the threading in the drain hole, so it popped loose, and it would pee fluid sometimes on the road (but not in my driveway). Gah! This was a tooling problem on their part -- dyes were not machined to the correct thread sizes. Not wanting to replace the radiator, I shamed the AZ people into lending me a tap, so that I could enlarge the threading to 10mm x 1.25 and put in a bolt. (My tap sets were in another city.) After re-threading the hole, I discovered that the Chinese tap had been horribly machined and had some horrible burs in it that buggered up the threading as I tapped it. The result? The bolt wouldn't hold either. So I ended up replacing the radiator under warranty -- another 2 hr of my time down the drain. I checked the plug very carefully before taking the new radiator. It did snug up firmly, so I guess they corrected the dye problem. Lessons: 1. Never trust a Chinese cutting tool! 2. Never trust a Chinese cutting tool! 3. Chinese workers don't give a @$%. That was 2 out of 2! The re-tap would have worked, but I was doubly condemned to failure. 4. Never use a Chinese part if it takes longer than a half hour to replace. 5. Probably stop using Chinese parts altogether. (Is this some sort of a Chinese plot to waste American time and resources?) 6. And once again, never trust a Chinese cutting tool! (Imagine if I had been using the thing to chase some threads in my cylinder head!)

Captain, I saved my original check valve, in hopes that you (I somehow knew it would be you) would come along later and figure out how to refurbish it. I'll keep hanging on to it. I see no reason why the inline check valve wouldn't work just as well as the one on the pump. You can always pull it back off later, once you've figured out the refurb process for our old ones. As a compromise fix, I wonder whether the check valve Wade sourced (NAPA ATM 1587010532) can be fitted with a nipple on the other end.

Holy moly! I was going to put one of those things on our boat! I may still do it, but I think I'll put fuses on both ends of the connecting wire. Thanks for the cautionary tale of your ill-fated solar adventure! Good luck with the repairs!

If you've got any varnish in your engine, you might have a hanging valve. I've never had this problem on an interference engine, but that's not to say it can't happen. Might also be rings. Might also be a dribbling injector and a flooded cylinder (flooded after engine shut-down from the residual pressure in the fuel rail). I'd say the conservative approach is to take some stone-cold compression readings. It wouldn't take very long. I think I'd do the following: 1. Start the engine, observe that it's still running on 5 cyl, and then shut down immediately. 2. Pull the plugs and examine them. Is the plug for the offending cylinder fuel-soaked or caked in carbon? If so, consider a fuel issue. 3. Compression test. 4. If all looks normal, then consider ignition issues. Swap the plug and wire of the bad cylinder with the plug and wire of a good cylinder. Did that transfer the problem to the (previously) good cylinder? If so, replace plugs and/or wires. (Of course you could also have a bad cap.)

Tomo, I think both mounting holes are the same electrically. Regardless, I'd bolt them both down tightly. Better two grounds than one! Z-ya, my HEI retrofit has been in use now for over 3 years, and my Z is a daily driver. (OK, I don't drive much, but still...) So there's nothing wrong with the concept. There has to be something wrong with your wiring. I can only guess as to what might run your engine successfully for a while and then fry the module. Here are a few guesses: 1. Heat dissipation issues: These modules are designed for pretty high temps, because they're ordinarily stuffed inside hot distributors. I've been told the modules don't need any special heat sinking and that they are fine mounted directly to the fender in the clamshell location. (The person who told me this had a '78 daily driver.) However, I always overengineer everything, and my module has a heat sink on it. Anyway, just check your module to see if there's any reason it might be overheating, which I can't imagine. FAIW, these modules don't generate a lot of heat. Mine barely gets warm enough to tell that it's warm. Of course that's with the heat sink doing its work. 2. Too much load. The only real load on the module is the grounding of the coil. One possible problem, previously discussed, is that you're trying to drive a ballast-type coil without a ballast resistor. I don't really know the accel coil, but be certain it's not supposed to be driven in series with a ballast resistor. The second possible problem might be that you're grounding the + side of the coil, where you're also supplying your +12VDC IGN. If you ground out your supply voltage, I suppose you can cause enough electromagnetic fluctuations in the coil to create a spark and run your engine, but the HEI module is really going to take a beating. This is all just speculation, but if I had to guess, I'd say the most likely possibility is that you're grounding your supply voltage and not the opposite side of the coil from your supply voltage. (For instance, maybe you've got your +12VDC IGN running to the neg post and are also grounding the neg post with the HEI module.) So make certain your +12VDC IGN and your HEI are wired to OPPOSITE sides of the coil.

z-ya, Pin #1 always goes to the negative, with any configuration, as far as I'm aware. The +12 IGN goes to the + side of the coil, and the ignition module grounds the other side of the coil to create the spark. Same story with a points ignition system. When the engine is running, an overly simplistic explanation is that the neg side of the coil goes back and forth between +12 and 0 volts, while the pos side of the coil stays at a constant +12V. In practice it really isn't this way. Rather, both sides gyrate wildly in voltage. You could probably trigger both your tach and ECU off of the pos side of the coil, but the neg side is going to give both devices a more appropriate signal that they are designed to read. FAIW, my tach jumps a tiny bit too, during hard acceleration. That's because there is sometimes slightly less efficient combustion, and this results in a recoil signal (not exact terminology here!) at the end of the ignition pulse, hence a "double" pulse. A condenser sounds like a reasonable way to fix the issue. I just haven't gotten around to working on mine yet.

Wow, what a flurry of activity on this topic! I've been busy building our dock -- dead tired -- so I've been away. I think Zed Head covered most of it. The tach/ecu wire seems to branch somewhere in the wiring tree. All you need is the one wire -- yes, to the (-) of the coil. The ballast-type coil might be a bit too much of a load on the HEI module without a ballast resistor -- might have fried it. A non-ballast type coil is probably a better choice. I use the Blaster II coil with good results. Tomo, I see no reason why you would have to disconnect any of the original IM wiring if you didn't want to do so. You could simply unplug the old IM and do as you will. I just hate stray wiring floating around the car. It seems like asking for trouble. You'll have ignition noise traveling around through dead-end wires (acting like antennas), and if anyone ever decides to plug back in an OEM IM, you'll have fighting ignition modules. I would simply isolate the input (reluctor from distributor -- red and green wires) and output (the ground wire to the neg of the ignition coil), and everything else can stay in place pretty harmlessly. My thought is that you still have the wiring in place, but it's not connected to anything and doesn't carry any voltages or noise. My entire approach to retrofitting is to make everything as painlessly reversible (to OEM) as possible.

You're probably pulling most of that moisture from the building materials. Once they're dry, you'll probably condense much less. Good weather stripping will be your best money spent, if you intend to keep the garage dehumidified. Don't forget to weather strip between garage door panels as well!

De nada, mi amigo!

To expand on what Walter and Tomo have written, the analog L-Jet ECU is an open-loop system with no lambda feedback (O2 sensor) or any other sort of feedback. It does not adapt and correct the way modern systems do. Also, unless you have a California Z, you have no catalytic converter. My end-of-the-line, Kentucky version 1978 280Z has a spledidly analog ECU, no oxygen sensor, and no catalytic converter. It does have "chips," but those chips are analog and packaged in oil cans -- probably not the sorts of chips you're thinking about. But yes, they came from silicon wafers (just like discrete transistors did/do).

Jenny, careful with those Fram filters! A tough guard filter is merely a crappy orange filter with grip paint. IMO, the best filter for a Z is a K&N. Here's a review of several filters with... er... very interesting commentary on the Fram. I can't say I disagree with anything he says, but I don't think I would have said it quite the same way.

You can still buy a product called Cosmoline. Maybe you can find a way to introduce some into the rails. I have no personal experience with the stuff, but I ordered a gallon tonight (about $125) for another project, and I'll occasionally find opportunities to apply the stuff in vulnerable areas of my Z (e.g. inside doors). I'm very excited about the stuff.

My guess would be the sender. It can read exactly that way when it goes bad. (Mine did.)

Jenny, I believe the AZ distributor is rebuilt by Cardone. The one I got was fine. However, I understand they sometimes bend the shaft a bit when they rebuild them, so be sure to check for any wobble. It would be worthwhile putting on a new boot. It's not a hard job taking apart that part of the throttle linkage. The risk, without a boot (and similarly with any other holes in the firewall) is that carbon monoxide from an exhaust manifold leak can blow into the cabin.

Tomo, just trace the wires with a multimeter! You might need an assistant, but hold one probe on the ECU #1, and the other on one of the disconnected mystery wires. If you've got continuity, that's the one. Andrew, I hate to say I'm in "life gets in the way" mode right now. We start building a dock on Thursday, and that's only the beginning of all our fun, including landscaping, grading, armoring of our shoreline, waging WWIII on an invasive species of marsh grass, adding on to our home, alternative energy, and probably a few things in the "etc." category. So I can't promise you a good, illustrated writeup anytime remotely soon. Until then, this will have to do (all from memory, so I might have an inaccuracy somewhere): 1. Remove the passenger kick panel, and uninstall the ignition module. Leave the wiring in place, in case you want to revert to OEM configuration in the future. 2. Locate the terminal block (a tiny black clamshell on the inside driver's fender) where the distributor's pickup coil connects to the wiring tree. Take apart the connections, and remove the terminal block, making sure to save it for later reversion to OEM. You may use the same threaded mounting holes to mount your HEI module. 3. Disconnect the wires from the (-) post of your ignition coil. Identify the wire that has conductivity with the #1 connector on to your ECU (beneath the driver's side kick panel), and reinstall it on the coil. Fold the remaining wire back on itself, and wrap it up in electrical tape. You may pull this wire back out later if you wish to revert to OEM. 4. Mount your HEI module to a good heat sink, and mount that heat sink to the fender, using the old terminal block's threaded mounting holes. Use heat sink compound between all mating faces. It is very important to have a good ground between the module and the body. 5. Replace the pickup coil's ring connectors with female spade connectors. Connect red to "W" and green to "G" on the HEI module. Lube all connectors with silicone dielectric grease, both here and below! 6. Install a wire from the HEI's "C" to the (-) terminal of the ignition coil. 7. Install another wire from the HEI's "B" to the (+) terminal of the ignition coil. Additional notes: See Tomo's diagram in post 19 of this thread for pin positions: http://www.classiczcars.com/forums/engine-drivetrain-s30/45070-gm-hei-upgrade-78-280z.html One person on this forum once swore that you should run a very beefy wire directly from your IGN+ circuit to the HEI's B terminal. However, the heavy current handling of the HEI is only from the coil to ground. The B terminal merely feeds the module's internal circuitry, so I don't think it has to be particularly beefy. You'll run the same +12 to the coil via the supply wire that was there to begin with, and it is heavy enough to support the current demands of the coil. The HEI module can simply be supplied with a small'ish branch off of that, perhaps 16 gauge. I used a square, finned heat sink for a power transistor to mount my module. I did this out of conservatism. Others (Steve Blake) have said no heat sink is necessary and that mounting directly to the fender is adequate. This makes sense, as the module is ordinarily in a pretty hostile (hot) environment, crammed inside a distributor. There are different versions of the HEI module. They all wire the same way, but some are higher specification (e.g. for very high RPMs). I used a very cheap/ordinary one, and it's worked great. My own successful installation was based on this writeup for a 240: GM HEI retrofit

Andrew, did you have the tach/ECU wire connected? If not, the ECU wouldn't have been triggered, and it wouldn't have delivered any fuel. Tomo, if I recall correctly, you keep the + wire intact. Then on the - side of the coil, there will be two wires. One will go to the old ignition module. (You can disconnect that one.) The other will go to the tach and ECU (see above). You need to preserve that one. And then there's the connection you add from the HEI unit to the - of the coil. I took my ignition module completely out, but I kept the plug and wiring intact, so that it could be easily re-installed or replaced with OEM. As I recall, I simply folded back the ground wire to the coil and taped it up.

Yeah, #38. That valve lets air move in both directions, but outflow occurs only with a good bit of pressure. I suspect the check valve could be removed, but I wouldn't swear to it. The only possible consequences I would anticipate would be fuel leakage through the bottom of the carbon canister (not likely) and the slow accumulation of water condensation in the gas tank (due to the tank breathing too much). If you drive your car enough to keep your gas fresh, water condensation should be carried away harmlessly with the ethanol. But too much condensation, and you'll have trouble with fuel separation and gunk/goo.

Hi Jenny, Wow, you've been moving along on this thing! I've been largely MIA because of a dock we'll be building. The contractor is ready to move on it, and I've been scrambling to order stuff and finalize the last design details. I'm fried! I think the recommendation for an engine stethoscope is a good one. You can buy one very cheaply from Harbor Freight, and it will work far, far, far better than a long screwdriver. Moreover, I think there's a very real safety issue. As a neurobiologist, I'm always cognizant of the example of Phineas Gage (whom you can google). Of course most people don't fare as well as he did after having long metal shafts launched through their skulls! Even being punched in a rather fragile area of your skull with the butt of a screwdriver handle would not be a good thing. A stethoscope is much safer, and the sound is far, far clearer. Personally, I would suspect a bearing, although I didn't hear the noise that well. As for predetonation issues, you really need to get a handle on your vacuum advance. If it seems sluggish or stuck, consider that it can advance on engine deceleration during closed throttle (when vacuum is highest) and then hang there. It's almost useless to set your timing when your vacuum advance (or mechanical advance) is sticking. Your timing could be almost anything. Personally I'd go for the rebuilt AZ distributor. There are aftermarket distributors (better ones) if that doesn't work out. Frankly the distributor is the only quite-bad component of this engine. Your AFM cover: There shouldn't be any noises from the potentiometer chamber with the cover removed, nor should you hear any vacuum noises. The cover simply keeps the innards clean. When you're completely finished working on the innards, you need to clean away all the old caulk, squeeze out a rather thin bead of new caulk (I like 5200 black) in the cover's groove, and squish it onto the AFM. Let it cure overnight before driving. But whatever you do, don't let the cover fall off! I have no idea how you would replace it!

Congrats, Jenny! See, I told you (or at least I told someone who I think might have been you) that it would be a highly pleasant job. The valve train is easily the prettiest working part of the engine, and there's something very satisfying about adjusting it to spec. And that gentle sewing machine sound.... PERFECT! It's how an engine SHOULD sound. (I don't trust those hydraulic lifters!) FAIW, I never had any trouble adjusting the valves with ordinary hand wrenches. But then again, I don't think I had a gorilla pre-torque them for me. When I first adjusted my valve lash, I found that two of my exhaust valves had NO (.000) clearance. Scary! Fortunately my compression is good, so none of the valves were burnt, even with the lean running.