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Thread: My '76 Z has a healthy crank but won't start!

  1. #1
    Registered User skunkbud280Z's Avatar
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    Angry My '76 Z has a healthy crank but won't start!



    I was warned and worried about fouled/contaminated fuel so I wanted to do a lot more fuel-prep work than just drain and refill the gas tank.

    I pulled the gas tank, got it cleaned at a local shop who gave it a Castic acid bath for a day, got it back last week but haven't reinstalled it yet. Blew all the bad gas out of both the feed and return lines with an air compressor (the feed line between the fuel damper and the fuel filter; the return line between the fuel rail and the fuel tank). The fuel in the feed line had some black flakes in it, the fuel in the return line had a bit of thick white junk similar to a jelly but otherwise the decade old gas looked clean and new in color. Changed the fuel filter, changed the oil and oil filter, drained and replaced coolant, replaced a bad fuel hose, replaced the leaky bypass hose(s) (why I stopped running it long ago in the first place), got some 93 octane gas with some gumout fuel system cleaner in it, and here I am.

    I have a 2-gallon fuel container sitting on a box right behind the fuel pump I'm feeding the fuel hose with gas. Incidentally, I have the rear of the car up on jack stands (using the proper jack stand points as instructed by the repair manual). The rear wheels and drums are off (bad break hoses and brake fitting nightmare but that's another story) and I don't think this has anything to do with why the car won't start.

    The hole on the container was wide enough to put the return hose in there as well, I've already verified the fuel pump is pulling fuel at a good rate, and there is fuel coming out the return hose when I'm cranking the engine.

    I verified there is spark in #2 and #3 cylinders by using a test light. I hooked the negative alligator clip up to ground and stuck the needle up against the metal contact inside the rubber boot of the spark plug wire and when someone else was cranking the engine I could see sparks in there. The cranking is really healthy sounding. Not too fast, not too slow, just like I remember it when it was running. It just won't fire up. I lifted the distributor cap to inspect inside. There was a bit of corrosion on the rotor head and contact points. Nothing to keep the car from starting I would think. I cleaned them up and put the cap back on. I felt air pulling into the air filter housing when the car was cranking. I know these are rudimentary checks I'm doing but I'm afraid I don't know much. Most of what I know about my Z I've learned in the past three weeks just reading the repair manual and hobbying away on it. Suffice it to say removing the fuel tank was a challenge for me, especially the venting vapor lines, but I succeeded at it without breaking anything. Not looking forward to putting the tank back on. I presumed it would be running by the time I got to that point.

    Anyway, I read elsewhere on the site that vacuum hoses can prevent the car from starting. There are some small rubber hoses around the distributor I observed today that were cracked and hardened and didn't seat together that good. I'm not sure why the timing would be off, it's only sat in the garage for 10 years. Not sure how to check for a bad timing chain or even set the timing. I see the adjustment screw on the distributor and I see the two little plates with the lines on them, and that they're offset from each other by a certain angle. If the rotor head spins counter-clockwise, the little bit of white corrosion on it would have been closer to the leading edge of the head rather than the trailing edge (relative to the middle of the rotor head). I presume this would signify a more "advanced" timing than "retarded" timing.

    Which is what I figured already anyway: The car is advanced and I'm retarded, it's okay, it doesn't mean that life is unbearable.

    I pulled the spark plugs out last night. They were all blackened on the electrodes and the insulators. I lightly sanded them and wiped them all clean and checked their gaps with a feeler gauge I bought. Not really sure how tight the fit is supposed to be but they all seemed to be gapped around 0.8mm.

    Anyway the car should be getting fuel as the pump draws the fuel out of the container nicely and I have fuel coming out the return hose. Doesn't mean the injectors are good but I don't know how to check the injectors and wouldn't they go bad one at a time? Would two or three bad injectors keep the motor from starting?

    I have spark inside the spark plug wires by using my test light probe grounded to the (-) battery terminal, but that doesn't mean it's a "good enough" spark.

    I haven't done a compression check. Seems self explanatory enough to put a compression gauge into the spark plug holes and check the cylinder compression but I don't know if this is a likely culprit of why it won't start at all. Seems implausible to me that it would prevent the car from starting when it ran very well the last time it ran a decade ago.

    Anyway, any general wisdom of what/how to check next, or most-likely-culprit information would be greatly appreciated.

    Thank you in advance!
    Shawn
    Last edited by skunkbud280Z; 09-06-2008 at 10:08 AM. Reason: clarification of some of my writing

  2. #2
    Registered User Curtis240Z's Avatar
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    I assume you were cranking the engine for some time, did the spark plugs smell of gas? Were they wet with gas? The most likely problem after 10 years would be clogged injectors.

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    Registered User skunkbud280Z's Avatar
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    Default You assumed right in all questions

    I had been cranking it for awhile already. A stupid mishap on my part happened which set me back a bit. I realized that the fat fuel hose between the fuel tank and the fuel pump wasn't long enough to sit down into the fuel container, so to remedy this, I got a section of my excess 5/16" injector hose and it just so happened to fit snugly up into the inner diameter of the fatter hose. After some undetermined length of cranking, the smaller hose slipped off the larger hose and fell into the gas can. I don't know how long it was in there and how long I was cranking without any fuel to the system, but when I saw this had happened I fished the hose back out of the gas, and got a clamp and right now I have the hoses clamped together so it doesn't happen again. As I said, I got a clean glass bottle full of gas and held it while someone cranked the engine and it quickly took half of the gas in that bottle through the lines so that'd be about what I'd expect from a fuel pump at ~35psi.

    The spark plugs were not only black but they were moist black, and yes they smelled of gas. For all I knew/know, I figured they would have still smelled of gas from 10 years ago and the smell didn't signify any fresh gas on them. I think if I can intuitively read what you're saying, I figured wrong. I thought the moistness on the electrodes was from oil coming through the rings as the FSM suggested, engine has 120k+ miles on it, all stock aside from headers/exhaust.

    I got some gumout maximum strength fuel system cleaner (cleans lines, injectors, everything) and one bottle treats up to 20 gallons of gas, I put half of that bottle into only 2 gallons of gas, which would have made the mixture 5 times more concentrated than what the bottle suggests. That was an arbitrary judgment call on my part. I didn't know how much to add, maybe I should have used the WHOLE bottle? *shrugs* A friend recommended that I let the car sit overnight or longer with that cleaner in the system to hopefully break up clogs in or to the injectors.

    Thanks for your reply Curtis. Perhaps you'll think if the plugs were wet and smelled like gas, the injectors would not be clogged...just about everything there is to talk about, is something for me to ponder about.

    It's still FUN though and that's what matters to me.
    Last edited by skunkbud280Z; 09-06-2008 at 09:52 AM.

  4. #4
    Former frequent poster sblake01's Avatar
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    Do you know for sure that the fuel pressure is 35 (actually should be 36.3 according to the FSM) and each injector has a pulse and is opening and closing?
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  5. #5
    Registered User skunkbud280Z's Avatar
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    Smile Forgive me for being so late

    I uploaded a video of the car cranking on Youtube and meant to post it on here but I lost internet for several days and never quite made it to respond temporarily from work. I just got the car fired up last night and uploaded the video of it starting a little while ago.

    I'm one happy clam right now as you can imagine!

    No and no to your two questions. I just visually observed the fuel pump taking fuel and presume that it's working just fine. It's what I would expect about 35psi to look like. I figured the easiest way I could hear the injectors pulse would be to be with a stethoscope (dunno, just guessing) and I didn't have one of those. I tapped on the fuel injectors lightly with a hammer, and they'd been saturated (I had hoped) with that fuel system cleaner for days now. I left the cap my fuel container all this time, I was wondering if the fuel would start to go bad as it's been sitting in there a few weeks now. Believe it or not there is no gas available where I live in Atlanta right now due to the hurricane. One station down the street was charging $5.50/gal for regular unleaded. I'm glad I bought this 93 octane gas when I did because it's the only gallon in town!

    I've been having fun chasing after bits and pieces of "stuff" in my fuel tank. Still haven't put it back on yet. It's sitting in the basement, I have all the holes plugged, and some gas in there I swish around now and then, and the dehumidifier is working overtime. I spent all night draining it from the plug to remove little flakes/pieces that roll/rattle around in the tank when I shake it.
    The reason it took so long is I spent about an hour trying to get the stuff out of the big hole, until I put my finger all the way down in it and realized that there is a cylinder of metal that extends down into the tank, and I realized any debris in the tank would have to come out the drain plug. I sloshed a gallon of gas through the tank several times and was removing a little more crap each time. Yes this is after getting it boiled in acid at the local radiator shop. They charged me $65 for the cleaning which seems to be a good deal. I notice there's a spot on the corner of the tank that was in the process of rusting out. There are going to inevitably be some flakes breaking off at that particular part of the tank unfortunately but the rest of the inside of the tank looks like new. Light grey and smooth instead of the red color it was when I took the tank to be serviced.

    Anyway a few observations about my car that have me perplexed. Obviously my fuel gauge isn't working because the tank is off therefore so is the gauge. But my voltage gauge isn't working either. I was wondering if that is because I disconnected the fuel gauge? They both share the same instrument. I doubt this is the reason why the voltage gauge isn't working but I'd love to hear that they share a circuit and once I plug the fuel gauge back in, the voltage will work again too? The clock doesn't work, but it stopped working before it stopped running 10 years ago.

    My headlights don't work. I wonder if I can just replace the bulbs and that will fix the problem? Do headlights go bad if they're just sitting in a garage for years, typically?

    And for some reason I'm missing the fuse for the dome light in my fuse box. Not sure where it went or if it was ever there, but my dome light doesn't come on either.

    I was flirting with this Multimeter on Amazon. I was hoping someone could recommend whether this would be a good one to run some more detailed tests on the electrical system in my car? Thanks!

    http://www.amazon.com/Actron-CP7677-...481640&sr=8-11

    Looks pretty sweet.

    Oh and here are the videos of the Z. Thank you for your help and my thanks for the great Z website.

    It was idling at about 600rpm during the video. I let it run for about 20-25 minutes and it was idling at 650rpm before I shut it off. It sounded pretty good, but I wonder if all six cylinders are firing right. Perhaps a test drive will be the best way to see.

    But my rear brake hoses are ripped, the rear master cyl. reservoir is bone dry, and I rounded off one of the brake fittings between the metal line and the rubber hose on one of the rear wheels. Used a flare nut wrench, it didn't matter. Those things are locked on there like superglue. I was using two Vice Grips on it since it was already rounded anyway, and even those couldn't get that damn fitting to come loose. I just about need to shoot it with my rifle but the bullet will probably ricochet off the fitting and it will still be as tight as ever. I've used WD40, over and over again. Does anyone have any magic answer to how to get these infernal brake fittings loose without causing any more damage?

    And can I "somewhat safely" drive the car on just front brakes? The master cylinder is supposedly dual circuit, meaning the front and rear are independent hydraulic pressure. Or supposedly they are. But I've heard warnings from friends that even so, I can lose all pressure in many instances with other vehicles. I noticed this happen on my Camry recently when I had a brake hose go bad on that. Barely got the thing home from my emissions test, total brake failure due to a torn line in the drivers side front. I had just bled the entire system at all four wheels and still had total hydraulic failure after driving only several miles. And despite the supposed "dual circuit" brake hydraulics.

    Oh and does anyone know what size/specification/brand/whatever of headlight this car uses, or that it should use? Thanks!!!

    http://www.youtube.com/watch?v=1sJ_vipQn7M

    http://www.youtube.com/watch?v=p5I8hjinY1w

    Crikey! I think I'm high on some nasty smelling fumes mate!
    Last edited by skunkbud280Z; 09-15-2008 at 06:19 AM.

  6. #6
    Former frequent poster sblake01's Avatar
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    What a difference a week makes! Fuel shouldn't go bad in just a few weeks. How much fuel system cleaner was in it? It takes a while for that to clear out but the car sounded pretty good to me though the idle was a little low IMO. You don't really need a multimeter with all of those functions. I have one that measures voltage, current flow, resistance, frequency, temperature, diode continuity, transistor hFE, dwell angle, and engine rpm. Haven't had it out of it's box in at least 6 months. I usually use the cheap little meter that I bought form Harbor Freight for $2.99. About the brakes, I've never attempted to drive one w/o front or rear brakes so I can't say much about that. The volt meter is tied into the fuel gauge ground. If it worked before it will work when you plug the connector onto the fuel sending unit. Z clocks are always subject to failure. Luckilly my original clock works but that puts me in the minority. Brake lines are always tough when they've been undisturbed for a long period. I use a flare wrench and tap it with a small hammer a few times and that usually works for me. But if they're the least bit rounded, it becomes kind of iffy. The headlights are the basic Sylvania H6024 or equivalent 7" dual beam. I'd check the circuit first or the continuity of the bulbs before replacing them.
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    Registered User skunkbud280Z's Avatar
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    Default Wow thank you Stephen

    for all the information! I'll buy a cheaper Multimeter then. I found a few better deals. That was actually a lot of money for me to spend, and less necessary for me to even buy one since the car is running.

    I'm really glad to hear that the voltage guage is tied to the fuel gauge ground! It did work before so I'm hoping it will work again! The charge light still comes on but I suppose that is separate. I was hoping I didn't reverse the polarity when I put in the new battery. --what someone like me thinks after I install the battery and look at the gauge

    Thanks for the info on the headlights too. I might wait on purchasing some new ones until I have some fun with the Multimeter. It's likely the bulbs I guess, and I've changed the headlights in this Z before. I remember how it took me about five minutes to change the headlights in my '72 Cutlass. Not so much for this car, I remember being out there almost all afternoon with it. heh

    Yep I remember hearing long ago about the failure with the clocks. Mine hadn't worked for at least a few years before I stopped driving it. Just a minor nuisance, I hate seeing what's involved with getting to those instruments under the dash. I don't feel comfortable with that amount of disassembly. Oh sure I'd take the whole engine apart if I had to, but only as an apprentice to someone who really knows what they're doing. The clock, at least for now, can wait.

    Okay I think I see from what you're saying that you use the hammer and the flare nut wrench AT THE SAME TIME! I was using them seperately. *slaps forehead*

    Respect,

  8. #8
    Registered User skunkbud280Z's Avatar
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    Talking New video on the Z running today

    Car is idling great, running really smooth. Can't wait to finish up and take it for a ride.

    Thanks again!

    http://www.youtube.com/watch?v=1wl0-hlQMzI

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    Registered User skunkbud280Z's Avatar
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    Default Two questions: One:Wheel cylinder grew(blew up?)while bleeding brakes?

    Two: Fuel gauge is indicating full tank although tank is almost empty.

    Re: problem #1:

    Well I got frustrated with trying to get that fitting off. If I want to replace the brake hoses it looks like I'll have to cut the line, re-fit it, and re-flare it, and I'm not looking forward to any of that. Don't have the tools or the experience.

    But while I was back there, I noticed on closer observation of the brake hoses that looked torn on the outside, I noticed underneath the black rubber "outer" hose that had cracks was an inner braided hose that seemed to be intact. I fed fluid through the rear master cylinder chamber and started th bleeding process at the slave (wheel) cylinders. To my pleasant surprise the hoses held the fluid, and the bleeding process was working. At least while I was still on the right rear wheel. I moved over to the left rear to bleed that one next, and while I was over there, I heard some noises to my right while my assistant was pumping the brake pedal, and I looked over there and saw a stream of liquid come pouring out of the wheel cylinder. Well in little time, the rear master cylinder was completely empty again (just like it was when I started the process). In a way I was angry at myself for "causing" the cylinder to go bad but in hindsight it's probably better that it happened sitting in the garage bleeding brakes than out on the road somewhere. I really wanted to drive the car though. Anyway I noticed that the wheel cylinder seems to have expanded outwards a good deal on the side with the rubber boot and the pin on it. The round metal that holds the rubber boot popped off and I can't get the boot to go back on. The lever that "auto-adjusts" on the gear wheel has completely separated itself from the adjuster wheel and also looks a little bent compared to the other one on the driver's side which is horizontal and straight with the teeth on the wheel. The shoes are so pulled out on the bottom now I wonder if I'll even be able to get the drum back on. My question is pretty easy for most to answer I suppose. And it's just this:

    Can I use the adjuster wheel to push the cylinder back in, at least so I can get the drum and the wheel back on? I should be able to use a slot screwdriver to do this. Also, and if so, which way should I rotate the adjuster? Assuming perspective of sitting at the rear of the car looking forward. I would guess the wheel only turns in one direction but that'd be a real drag if it's not the case and I accidentally turn it the wrong direction...

    To replace the cylinder I'm going to have to take the brakes completely apart, and that means another fitting at the cylinder needs to come off and after having such a nightmare with the other fitting, I don't even really want to touch it. I'll let a real mechanic with a blow-torch or a magic vice-grip or whatever take it off.

    I'm wondering if maybe the wheel cylinder isn't bad and it just pulled apart too far and is SUPPOSED to let fluid out when that happens?? Maybe it's a matter of bleeding the brakes wrong somehow. Can never be sure.

    Re: problem #2:

    I got the fuel tank back on. It went on perfectly. Really happy about that. However, when I plugged my fuel gauge back in at the tank, and turn the ignition on, the fuel gauge on the dash is indicating a full tank and I know I only have two gallons in the tank. Also the voltage meter still isn't working, although it gave a little wiggle when I turned the ignition on the first time. At first I thought I plugged it in wrong but on careful study of the manual I see the plug is "keyed" so you can't do it wrong. One other possibility is that I put the actual float mechanism in the tank wrong. I thought I put it in right. With the float sitting horizontal (parallel to fuel fluid surface) and down at it's lowest point. I assumed the fuel level would make the float rise from that low point. Could I have put it on backwards so that the float is sticking up at the high point and then gravity alone causes it to drop and the fluid level opposes that gravitational force?

    Thanks

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