FastWoman

As grantf suggests, you can plug a miniature Christmas tree light bulb into your injector connector (i.e. after unplugging an injector). The light should flash once per rotation of the engine (twice per 4-stroke cycle). The FSM says to test your ECU by unplugging the coolant temp sensor and seeing whether the light flashes brighter/longer. I would imagine an ECU could be half dead and still pass this test, but that's what the FSM says. You say you did some ignition work. If you don't have connectivity between the (-) post of the ignition coil and the #1 pin of the ECU, the ECU will not detect rotation of the engine and will not fire the injectors. Check your connections.

Can't have too many gauges! Your fuel pressure on your return line should be nearly zero. If you do have pressure there (especially after you relieve any air pressure in your gas tank), then you have a blockage somewhere in the return line. The best place for a gauge, IMO, is inbetween the fuel filter and the supply tube to the fuel rail. You should use 5/16" barbs -- no smaller and no larger -- for your fuel lines. Too large a barb will eventually split your fuel line, and too small a barb just won't hold the hose. I wouldn't worry about flow restriction. I know people get all freaky about flow restriction, but the fuel doesn't really flow all that fast. 5/16" is plenty adequate.

I think the towel around whatever hose you intend to disconnect is about as easy as it could possibly get.

FAIW, I installed a guage permanently with parts from my local True Value. They have a $5 Chinese gauge that's pretty accurate. It has a 1/8" NPT fitting. I screwed it into a 1/8" NPT "T" fitting and screwed a couple of 5/16" barbs into the other two holes. I installed it inline between my fuel filter and fuel rail. Works great. Total cost was under $10. You can test your vacuum advance without a mightyvac. Just suck on the tube REALLY HARD. You should be able to move the breaker plate. You can also try moving the distributor's breaker plate by hand. It should turn smoothly, without binding. Yogurt cup test: One chest full of air should do the job.

That's a pretty long, convoluted tube. I doubt you'd be able to slip anything inside it. Maybe see what a radiator shop can do for you? They sometimes work on gas tanks.

^^^ not a bad idea!

I'm surprised! Just go to the plumbing section. Look in the parts bins for small brass fittings. Well, I don't know how much this really tells you. I know for a fact that my engine is very tight, but I don't get the same huge difference when I pull the oil filler cap. I do get air throught he hole, and the engine runs a bit rougher, but it's nothing dramatic. I think that has to do with my PCV valve, which is new. I think it passes less vacuum than my prior PCV valve did, and with that valve, there was a more dramatic difference when removing the oil filler cap -- even though I had vacuum leaks going on at the time! There's a quick way to test for vacuum leaks. When you get your new AFM and boots, first connect up just the boot that goes to the throttle. Then stuff something (I use a yogurt cup) inside the boot opening to block the air. Pull off the vacuum hose to the brake power booster, and attach a hose to the manifold that you can stand to put in your mouth. Then blow into the manifold like you're inflating a balloon. The pressure will build, until you can't blow anymore. Just hold the pressure there, and see how long it takes to dissipate. It should take probably 15 sec or more for most of the air to leak back out. Then pull off the little vacuum hose beside the brake booster hose, and repeat the test. You'll see/hear/feel lots of air coming out through that little nipple, and the air pressure should leak down MUCH, MUCH faster. If there is a dramatic difference between the two, your intake and engine are tight. If the difference isn't very dramatic, you have a leak somewhere. If you do have a leak, I suspect you can find a smoker (hopefully not you!) to blow cigarette smoke into the manifold. It should come billowing out wherever you have a leak. I've never tried this (non-smoker living amongst non-smokers!), but I bet it works quite well.

I would GUESS a busted spring would result in too low an oil pressure, but I don't really have any experience with that. I suppose it's also possible to have a jammed relief valve (from debris from the spring?), which would result in high oil pressure. FAIW, your oil pressure should naturally rise and fall with the engine speed; however, it usually stabilizes at a moderate RPM and doesn't get much higher at a high RPM.

You're welcome! No prob... To get your static reading, just hook the gauge directly to the outlet of the fuel filter (i.e. with no "T" fitting and no connection to the fuel rail). Disconnect the starter wire from your starter (the little one). Watch the gauge as you turn the key to "start." You should have 5 sec of pumping, and your fuel pressure should go up to 45 psi or better. IF YOU NEED TO, you can hot-wire your fuel pump directly without damaging it. I don't know which terminal is which. With the engine not running, just put a multimeter on it, ohms mode. One terminal will have zero ohms to ground, and the other will have infinite ohms. You can connect +12 to the side with infinite ohms to run the fuel pump. If you're getting 36 (or 35) psi fuel pressure, that's fine. I'm suspicious of your measurements, though, as the 25 seems a bit low. I wouldn't pin that on a bad FPR, as it's a pretty simple device and could only give you inch-for-inch compensation in fuel pressure as vacuum is applied. I suspect your gauge might be sticking a bit somehow -- or might be inaccurate.

No, you won't ruin the FPR, and yes, you need a good ground.

Well, with that hose disconnected, you were running with more fuel, which made the engine run stronger. With the vacuum line connected, you get backfiring through the intake ("burps"). That confirms a lean condition. Your FPR might indeed be bad. Or maybe you have an inaccurate gauge, and other stuff is causing you to run lean. However, I think replacing the FPR would be a good move. Just the same, it would be great to have a static fuel pressure reading from that pump, just to make certain it can put out the needed 45+ psi.

You can get "T" fittings at any hardware store for your fuel pressure gauge hookup. You'll want a "T" fitting with 5/16" barbs. Is there any reason you're wanting to change out injector hoses or injectors? If you don't need to do it, I wouldn't. When I suggested changing out vacuum lines, I only meant vacuum lines. Even if you want to change out fuel lines (not a bad idea, really), I'd leave the short hoses on the injector rail assembly as they are. You'll definitely need the correct model of AFM to start with. You'll know much more about your engine after you get that corrected. Fuel pressure and fuel line diameter -- You've got a lot of factors mixed up here, but a blockage in the return fuel line could cause an elevation in fuel pressure. However, a smaller diameter fuel line isn't going to amount to much. Fuel isn't gushing through those lines like water through a fire hose. If you're tweaking your afm to open up the vane (to deliver more fuel), and if that makes the engine run better/stronger, with more vacuum, then you're ordinarily running too lean, not too rich. I don't care what the smog report says. The split in your boot could be part of the problem. You can still buy that part new from Nissan. Try Courtesy Nissan on the web. You don't need to remove your dash to check your flashers. Your flashers are up under the driver's side dash. Just lie on your back on the floor, and look up. There's one for the turn signal and one for the hazards. If I recall correctly, the hazard flasher is up above the hood release somewhere. If not there, it's near the steering column above the pedals.

I have to go, so I don't have much time to post. I'll be back later. IF your fuel pressure is high, it's going to contribute to rich running. Your problem is opposite. So if you fix the high fuel pressure (e.g. replacing regulator), it's going to make your engine run worse. That doesn't mean it shouldn't be fixed (if it's broken, that is). Your first job is to search for vacuum leaks. All your vacuum tubing, if old, is suspect. I'd replace all old tubing/hoses with new. It's an easy job. Also check the big rubber boot between the AFM and throttle body for splits/cracks. Some of us are finding that our ECUs have drifted over the decades, resulting in inadequate fuel delivery. There's a remedy for that, but before doing it, you have to get everything else straight with your engine. BTW, since you've been into the ECU, take a look at the silicone rubber blobs on the clock-spring wheel. Do they appear to be factory blobs, and are they still intact? It's important to figure out whether anyone's tampered with the AFM's factory settings. If so, you may need to recalibrate. Finally, you can download a factory service manual for free from xenons30.com. Go to section EF, and you will find lots of diagnostic procedures you can follow. There's a big connector on the ECU, just under the driver's side kick panel. I'd suggest doing all the electrical measurements there. It's a good way to check both your components AND your wiring and connectors, all at the same time.

Well, there's another test you should do for your fuel pump. Just disconnect the hose from the fuel filter to the fuel rail, and hook a gauge up to the outlet of your fuel filter. That will give you a static reading. It should be approx 45 psi or better. You should probably do this test after your system gets warmed up enough for you to see that small pressure drop you mentioned. FAIW, before I replaced my pump, it woiuld give me about 50 psi when cold, but as I ran the thing for 5 or 10 min, the pressure would sag down to about 25 psi. I think it would really sag much farther than that, as my immediate problem was that the engine had died and left me stranded on the side of a highway. (Grrrrrrrr....) You're right... better to have one issue per thread. There's an exhaust section, and lots of people have expertise in exhaust. However, they might be carb people and might have no interest in checking the fuel injection section. ;-)

Well, the 36.3 psi reading would be without compensation for intake vacuum (i.e. with the vacuum hose disconnected from the FPR. It still sounds low, though. Assuming the engine is pulling a really healthy vacuum of 19 in Hg, there should be almost a 10 psi decriment in fuel pressure, which would put the correct pressure at maybe 27 psi. Realistically, our old engines don't pull the vacuum they did when they were fresh (unless they've been rebuilt), so a pressure of 29 is more likely. (That's where mine runs.) Is that far enough from 25 to be low? Dunno... How accurate is the gauge? It still sounds a bit low to me, but it's not EXCEEDINGLY low. If the fuel pressure IS low, it could be the fault of the pump, the regulator, the damper (rare problem), the fuel pickup screen, the fuel filter, or the fuel lines (clogged). To rule out a number of these items, I'd suggest finding a length of clear vinyl hose and hooking it to the outlet of your fuel filter. Then hot-wire your fuel pump (+ to the + connector on the pump), and see how the fuel flows. You can either pour the fuel directly back into your tank or spill it into a gas can. You should see a healthy flow. If the flow isn't healthy, then something's probably blocked up. The next test would be to reconnect your fuel rail to the fuel filter and hook the vinyl tube to the fuel return outlet of the fuel rail. As your engine runs, you should see a healthy return flow. If not, your pump's output might be inadequate. (That's how my own pump failed, BTW.)

You don't need to replace your oil pump. If it's a gummed up relief valve, you might be able to solve the problem with an engine flush. Next oil change, run some Gunk motor flush in the crankcase for 5 min before draining your oil.

Check your throttle position sensor (black plastic box on the side of the throttle) to see if it's clean and adjusted properly. If I'm understanding correctly, the engine won't rev beyond 3k. That could be because your TPS is stuck in the idle position, so that fuel is cut above 3k. Fuel pressure: Might be a bit low. While the engine is running, pull the vacuum line off of the fuel pressure regulator. The pressure should then be about 36 psi, as I recall. Be aware that your fuel pump can test good when cool, but become inadequate when it gets warm/hot, so test it after running it for a while too. It is normal for the fuel pressure to drop off as engine vacuum increases. In fact the fuel pressure is held constant with respect to intake manifold pressure, if that makes sense. Welcome, BTW!

Well, yesterday I had many of these themes come up in the same conversation, when I showed my "new" Z (had it now for 2 years) to some out-of-town relatives. They both commented how cute the car was. One of them pointed to the inspection flaps and asked if those were the headlights. I explained that they were just flaps. They both asked what the car was, and I told them a '78 280Z. One of them then commented, "They haven't changed much, have they?" I think he though the car was recent. I explained, "No, this car was built in 1978." Then he repeated, apparently not understanding, "Yeah, that's what I mean. They haven't changed much at all." I guess he still didn't understand that I was referring to the very car I was driving, as opposed to the model. I guess he thought the model must still be in production, since apparently I had just bought one. After asking me about the Z, he asked me about my 2001 Z3, asking if I still had "that old yellow car." Mind you, the old yellow car was in show-room condition, so I guess it was just the body style he thought made it an antique. Go figure. Then the other relative (who apparently grasped that the Z was an antique) asked me how fast it goes. I replied that I don't know -- that I've never driven it that fast. Incredulously, and with a smirk on her face, she quipped, "WHY NOT?!" (This comes from an elderly, retired primary school teacher.) I told her that in its day it would go around 160. In hind-sight, I think I should have told her, "I don't know. I'm not dumb enough to try driving it that fast.";)

That happened to me too, and yes, it's a bit scary. I just watched carefully, and after 5 or 10 min, there wasn't any more smoke. It was definitely all the penetrating oil. It gets everywhere, including in the pores of the metal. Glad it runs better!

Wow, congratulations! Yours was a LOT easier than mine. I'd recommend you replace all the fasteners, whether they look like they need it or not. I sprayed both sides of my gasket with this: http://www.google.com/products/catalog?q=copper+gasket+spray&rls=com.microsoft:en-us:IE-Address&oe=&um=1&ie=UTF-8&tbm=shop&cid=7438551903716389274&sa=X&ei=3ctHToDXC6ipsAKJypDXBQ&ved=0CC4Q8wIwAA# ... and then I thinly coated all the port holes on both sides of the gasket with this: http://www.permatex.com/products/Automotive/automotive_gasketing/gasket_makers/auto_Permatex_Ultra_Copper_Maximum_Temperature_RTV_Silicone_Gasket_Maker.htm I don't know what brand of gasket I installed. I ordered it from MSA, and it came in an un-labeled plastic sleeve. It looked reasonably substantial, to my untrained eye. Wow, if your gasket was as bad as you indicate, this should make a HUGE difference in how your engine runs!

Grant, I just re-read your post. I now see you're talking about the heat shield BETWEEN THE MANIFOLDS. Right? (I thought you were talking about the exhaust shields hanging down below.) OK, this is easy: You don't remove that one! Believe it or not, you can slip a socket with two extensions right underneath it. Just get some light under there, and peer in sideways with a mirror. You'll be able to see all the studs shared between the intake and exhaust manifold -- the ones with the big hold-down washers. As I recall, it's a bit of a squeeze to get to the forward-most one, and it's necessary to flex the heat shield just a bit, but your drive will fit in there, possibly with one long and one short extension, as I recall.

Grant, yes, you've got a lot of heat shield under there. I honestly can't remember how it all bolts up. (It's been a year.) However, I do remember all the heat shield bolts are easily accessible. The hard part is FINDING them. Your best friends will be a good drop light and a small hand mirror. You'll also need to remove the shielding around the brake master to get the EGR stuff loose, so you may as well remove that now if it's in your way. In general, if you can't free a bolt with Kroil, heat, tapping, gentle persuasion, and the requisite swear words, your only option will be to ring it off and deal with it later. You'll probably have to "give up" on a few fasteners to get the job done. That said, my heat shielding came off just fine. The real problem points for me were the manifold studs near the front of the engine (from chronic coolant seepage) and a few bolts on the top of the manifold that held down brackets and emissions stuff. I think my corrosion was probably about as bad as it gets.

Check your gas cap's vacuum relief valve. As long as that's working, you won't get a problematic vacuum in the fuel tank. That said, I think you probably should have your charcoal canister connected up. There's no reason NOT to, and tampering with it is actually illegal. (I'm imagining a conversation in a jail cell: "So what are you in for?" "Tampering with a carbon canister." "Oh god! Stay away from me! I don't want NO TROUBLE from you!") A problem that suddenly comes and goes sounds VERY ELECTRICAL to me. I'm always suspicious of crusty wiring/connections. You might learn a lot by pulling off the ECU connector (WITH THE IGNITION OFF!) and going through all the measurements in the factory service manual (which you can download for free at www.xenons30.com). By measuring at the ECU, you will not only be determining the state of your various EFI components, but also the state of the wiring and connectors. If your connectors are anything like mine were, they're pretty crumbly and corroded. You can buy new 2-connector Bosch-style connectors (the style on your injectors) on Ebay from a seller called "f0rrest."

Cool! I had looked for a Schrader valve at various auto parts stores, and the folks all stared at me like I was dressed like a Viking and speaking Portugese. All I wanted was an easy means of checking fuel pressure, so I simply installed an inline fuel pressure gauge. I've described it elsewhere, but I'll also describe it here in this thread as an alternative that someone might like. The gauge ran me $5 at my local True Value hardware store. It's made in China -- 100 psi max, about 1.5" in diameter, with a 1/8" NPT thread on it. I screwed that into a "T" fitting with 3 1/8" NPT threaded holes. I screwed 5/16" nipples into the other two holes. The entire assembly was under $10. The "T" is oriented with its "bottom" (the stem at the bottom of the letter "T") pointed downwards and connected to the top of my fuel filter via a very short length of hose. One of the "arms" of the "T" has a 5/16" nipple that points directly towards the fuel rail and is connected to it via a short length of hose. The other "arm" of the "T" holds the gauge, whose face points straight upwards for easy viewing. No brackets are necessary, as the gauge is held quite steadily on the ends of the short hoses. The installation looks very neat, and the gauge has held up fine in the summer heat. (I was worried about the possibility of softening solder joints.) Also my car is a daily driver, and I've noted no corrosion or deterioration in the gauge so far. Finally, the gauge is surprisingly accurate for a $5 item out of China.

YUM! That's DEFINTELY chess pie! What it's doing in your water pump is an interesting question indeed. Seriously, could that be some "stop leak" treatment?