the_tool_man

Got back from the UK last night, ready to resume on the car. Walked to the shop to find a tree had blown over. Backed the car out and pulled the wheels. Took the wheels to a tire place for new tires. Started the car to drive it back into the shop, and noticed that now the tach is inop. One step forward, two steps back. Gotta deal with the tree. Then I'll pressure/flow test the fuel pump.

I didn't even know that existed. Cool.

I plan to. I'm traveling this week, with plenty of time for researching, dreaming, planning and asking annoying questions, lol. Testing resumes this weekend.

Great info EuroDat. Not trying to hijack Wheee's excellent restoration thread. But this seems like an appropriate place to ask: As my fuel pump is suspect until I can test it next week, I've been looking at pumps too. I noticed a bunch of "replacement" ones. I assume they are "replacement" in the sense that they are fuel pumps that provide enough pressure and flow, but not mechanically identical to OEM? For example, I see on RockAuto they have the Beck/Arnley OEM pump for $396, and several "replacement" ones, such as a Delphi for $81, and others. If one doesn't care about originality, or needs one for temporary use, wouldn't this be another option? I'd assume a mounting bracket or adapter would be necessary.

I ordered some extras. I've done crimping before, just not with these specific connectors. I got the pin removal tools for two reasons: 1: so I could disassemble the connectors before trimming the wires, as I want to keep as much of the original as possible (the AFM cable in particular doesn't have much slack in it), and 2: because I might need to take one apart for some reason other than to replace a crimp. Or maybe I just like accumulating tools. My connector does look just like the top one in your photos. There was no wire on it. I haven't heard anything back from Kurk. So I gave up on him and ordered this kit from Ebay: http://www.ebay.com/itm/161969530205 Since I bought the extraction tool for the pins, I have the option of using new pins on the original wires, if they're long enough. If not, I can splice the pigtails.

Describing what's going on, while limited to a keyboard, has its limitations! Part of the problem is that I leave out details that seem minor. Let me elaborate on my description: The engine starts easily. If I allow it to idle, it stumbles while idling, and dies after 10 seconds or so. The AFM vane moves off its stop while idling. If I rev it to 2000rpm or higher, it will continue to run. While running, it continues to stumble (misfire, skip, whatever). While it's running, the fuel pressure drops to "near zero" on the gauge I'm using. That gauge has a pretty big range (0-160psi). And "zero" looks to be more like 5psi. So I can't really say it goes to zero. I assumed, but didn't specifically communicate, that it was getting enough fuel to run even though the measurable pressure at the gauge is quite low. I really appreciate all the suggestions. They're pulling me in different directions! But I'm going to concentrate on the fuel supply first: When I'm home next week (traveling in the UK at the moment), I'll test the fuel pump for pressure and flow, and investigate possible flow issues with the tank and lines. I've ordered a replacement FPR, since the one on the engine may well be original, and is suspect. Hopefully, it will arrive early next week. I realize the one I have may be working fine. And I know how to test it. But it's an easy job to replace it. And I want to be able to take the car on long trips. So for peace of mind, I'm going to just replace it. Zed's theory about it leaking fuel into the intake sounds intriguing, as it explains the low pressure and rich mixture (if that's truly what's happening). So again, one more reason to just replace the thing. On my longer term list: I noticed my fuel gauge reads half-full. I know the tank was full when I brought the car home (I filled it up). So while not necessarily urgent, I need to sort it out pretty soon. I may end up pulling the sender anyway during the course of the fuel supply investigation. But if not, it won't hurt to pull it to inspect the inside of the tank for rust and debris. If I had to drop the tank to do this, I'd probably put it off for as long as possible. But between the tank drain and the inspection panel in the trunk, it looks like an easy job. I plan to replace all of the EFI connectors with new ones. Firstly, the AFM connector on my car was missing the wire retainer, and is currently held on with wire ties wrapped around the AFM. Secondly, while the contacts aren't green, they are somewhat corroded on many of the connectors. I've inquired about replacement connectors from a guy (Kurk MacKay of MacKay Power Products) recommended to me on Hybridz. He's been slow to communicate. But he offers a kit that has everything I should need. I've already ordered the pin removal tools and a new crimper to facilitate this. I still haven't completed all of the electrical tests as outlined in the EFI book. I'll do these as time permits, just to eliminate other potential issues. I need to go through the ignition system, if for no other reason that to make sure everything is in good shape. I have to repeat that amount of help here is overwhelming. I'm not used to this. Thanks!

Zed, I've confirmed that the contact in the AFM is working properly. I can see, with its cover off, that the flap stays open while the engine is running. I can hold the engine at 3000 rpm, and it runs. But it misfires, I now believe, due to fuel starvation. And for the record, I haven't changed the adjustment of the AFM spring from how I received it. All I've done so far is check and clean electrical connections. You and EuroDat have both suggested disconnecting the start solenoid to further test the fuel pump. I will do that next. I can at least determine if its building enough pressure.

Crimper tool and pin extraction tools are ordered. Made contact with Kurk about a connector kit. Thanks for the help.

Update: The visit to the pull-a-part yard was a bust. So I bought some brass fittings and a pressure gauge and spliced it into the fuel line after the filter. I put in a new filter, too, even though the one already installed looked brand new. It was fun to test without a helper. I had to lean in through the passenger side window to start it, and then try to watch the pressure gauge while manipulating the throttle linkage. But I determined that when cranking, the fuel pressure would build to about 20psi. Upon starting, it quickly (5-10 seconds) dropped to zero on the gauge. I could keep it running by revving it. But it sputtered, as you would expect. So the fuel pump is running (eliminating electrical fault, contact in AFM, etc.), but it is either worn, or there is a blockage somewhere. I'm not sure how this explains the symptoms of running rich. But that seems to have been a red herring. My next step is to run new fuel lines from the pump inlet and return line to a gas can in an attempt to isolate the issue to either a dirty tank/pickup or a weak fuel pump. I was pleasantly surprised to see a drain plug in the fuel tank, BTW. More to come.

So will the standard "Open Barrel" die set work on these terminals? I just want to make sure I get the right thing. I've contacted FricFrac about a connecter kit. Now that I've read the terminal replacement tutorial, I see the difference in the connectors. I also now recognize that at least one of mine (coolant temp sensor) has been replaced. I noticed when I was debugging that circuit that the connector used the newer wire retainer, and that there was a bulge in the harness a few inches away. I thought it might be a resistor installed to fool the ECU. But it ohmed out with no resistance. Now I realize the PO must have bought a replacement connector with pigtails and spliced it into the harness. Thanks!

Got it. Thanks. I tried to find an inline fuel pressure gauge yesterday to facilitate testing. But none of the local parts stores I tried had one. I'm taking tomorrow afternoon off, and will go by the local pull-a-part to find a late model fuel rail with a built-in Schrader valve so I can use the gauge I have. I also picked up a new fuel filter, even though the PO said he had just replaced it before I bought it. Stay tuned.

Yep. My 25 year Sunbeam project started out as "this car almost runs", and quickly became "the engine needs rebuilding", and then much more slowly became "I should just part this car out". I will NOT do that again. I probably won't live that long, anyway, lol.

If I'm brutally honest with myself, this statement describes where I've been with the car since I bought it. I've been assuming it would be one or two easy things to fix, and I'd be driving it. That's what's frustrated me. I just need to get past that and be methodical.

I'm going to put in a new fuel filter and a fuel pressure gauge. If nothing else, this will rule out fuel supply issues. The engine revs fine. The plugs are sooty (see pic), indicating running rich. So I doubt it's a fuel supply issue. But it doesn't hurt to check. Like I said. It'll be a couple of days before I can get to it.

I'm not sure. My connector has no wire, and doesn't appear to have any provision for one. I think it used some other retention method. Good news about reusing the wires. Thanks.

This is taking longer than I thought. I didn't get much time to work on it this weekend, due to some issues that came up. But tonight, I went through the temperature sensor circuit. I drained the coolant and removed the sensor. It checked out, reading 3.5 kOhms in my ~55 degree shop. I could even get the resistance to drop by holding the end with my fingers, as you would expect. I cleaned the bullet connectors in the harness over the intake, and checked continuity in the harness where I could. Once I did that, the resistance at the ECU plug read correctly. I was very hopeful that I'd solved it. I refilled the coolant. I pulled the spark plugs. They were completely covered in carbon, from running rich I think. I cleaned and reinstalled them. The connector on the bottom of the AFM wouldn't stay plugged in (I think it's broken). So I used a couple of crossed loops of wire ties to hold it. I hooked up everything, crossed my fingers and turned the key. No difference. At idle, it stumbles and dies after a few seconds. I can rev it to 2000rpm, and it'll run, badly. The search continues. Next session I'll try the cold start valve and clean all the other connectors I can get to, etc. My next opportunity to work on it won't be for a couple of days. That's a good thing, as I'm so discouraged, I don't want to look at the car right now. I did get the car titled and insured today. That's something, I guess.

Thanks S30driver. That looks like the ones I saw on Ebay, too. Not looking forward to soldering all those wires. But that beats my current solution, which is wire ties wrapped around the AFM to hold the connector on.

Hi all: I searched here for the answer, and I Googled a bit for a source. But no luck so far, other than Ebay, which has connectors that don't look the same as mine. I noticed on my '77 (that I just bought) that the AFM connector does not seem to have any retaining means in the AFM. If I unbolt the AFM, the connector falls out as soon as I move it. I'm concerned the connector will fall out while driving. Is there a source for a replacement connector, aside from getting an entire harness? I can't even tell what is supposed to retain it. But I assume this is not an uncommon issue. Before I shell out $300+ for a harness, I'll explore a home-made solution. But I'd rather replace the plug (or whatever retains it if that can be retrofitted). Thanks in advance, John.

First, I visually inspected all of the vacuum hoses. I couldn't find anything wrong with any of them. I even removed the large hose from the valve cover and intake coupling behind the AFM, just to make sure (losing part of the wire hose clamp in the process, grrrr). All looked good. Second, I performed the "yogurt cup test". I'm not sure that really does anything. After using a yogurt cup, of all things, to block the intake, and taping over the T fitting on the vacuum hose to the valve cover, I disconnected the brake booster vacuum line at the firewall connector, and used some clear vinyl tubing to pressurize the intake. I found that it built pressure immediately, until I felt something give way, and then had a constant leak accompanied by a trumpet sound. When I sucked on it, it would pull vacuum immediately and hold it. I'd let the end of the tubing suck against my lip for a few seconds, just to make sure. The weird thing is, I could remove the oil filler cap or the plug in the end of the hose to the valve cover, and it made no difference. So I don't know any more than I did. Next I pulled the ECU connector and measured the resistance of the coolant temperature sensor circuit (pin 13 to ground). It measured 13MOhms, essentially open circuit. That's not right! Tomorrow, wife permitting (it is Valentine's day after all), I'll check that circuit as suggested.

Progress. It runs! Sort of. I removed the AFM, and after opening it, realized it had been messed with. The glue blob on the locking screw was broken. And it looks like the black gear has been adjusted 6 teeth clockwise from where it should be. At least that's what the white marks on the body of the AFM and the black gear seem to indicate (see photo). I went through the electrical tests, and found that the fuel pump cutoff circuit was intermittently open. A quick pass over the contacts with some emery paper and alcohol fixed that. Everything else on the AFM checked out fine. The air passage was dirty. So I cleaned it. I decided not to attempt any adjustment of the black gear yet. Anxious to see if that fixed it, I reinstalled the AFM and started the car. As long as I gave it enough throttle to maintain 2000rpm or more, it ran. But it sputtered and smelled sooty like it was running rich. I tried the "fingering" test with the AFM to see if I could effect the mixture. But it didn't seem to make any difference. I ran it for about 15 minutes, letting it warm up. I'm not sure why I did that, other than in the hopes that running that Star Tron through the injectors might clear things up. It didn't. Still, now that I can get it to run, I've eliminated fuel pump and ignition as the source of the issue. Now I can go through the troubleshooting process to get it tuned. Tomorrow, I pull the wheels and get them re-shod. EDIT: I just noticed the last several posts with good ideas for easy stuff to check. I'll test for vacuum leaks and bad connections tomorrow. I'll also look at the plugs and see what that tells me. Be patient with me. I've not spent much time tuning pre-OBD cars. Stay "tuned", lol.

My thoughts, exactly. Don't forget, we got the engine to run by mechanically forcing the AFM vane open.

Thanks for all the help. I've still not carved out much time to work on the car. I did get the mildew stains on the bottoms of the door cards cleaned up. I "Lysoled" all of the hard surfaces inside the car and left the windows open to let it air out. Regarding my learning, I've downloaded copies of the FSM, 280Z FI book, 1980 EFI bible (seems redundant), etc. I read the first section of the 280Z FI book, and have read the AFM calibration website (though the HTML seems to be messed up, causing much of the text to overlap images toward the bottom of the page). I've also ordered a Haynes manual, though it'll be somewhat redundant. And I've spend a little time locating the various EFI components in the engine room (I love that the FSM calls it "engine room"), checking for loose connections or PO modifications (finding none of either). My AFM appears to be un-tampered with. I assume the black cover is glued on, and has to be pried off (amazingly, I haven't found instructions for that anywhere. I guess it's one of those intuitive things people just know). One thing I did note was that when I start the car, it dies after a few seconds no matter what the throttle setting. Whether idling or revved to 3000 rpm, it dies. I can't imagine there would be a vacuum leak big enough to allow the AFM flap to remain closed at 3000 rpm. That's easy to visually verify, once I arrange for a helper to start the car for me. If it is staying closed, I think its stuck from being dirty, or held closed by a broken or misadjusted AFM. If neither of those, I'll look for leaks. Weekend plans include (in order of priority): Take the wheels off and get new tires installed (old ones are dry-rotted). Visually check operation of AFV flap. If sticking, clean air passage and attempt to lubricate pivot. What lube should I use here? I don't want to foul electrical contacts inside the AFM. Depending upon the result, I'll open the AFV cover and go through visual inspection and calibration as advised. One thing that wasn't clear to me. Can the electrical measurements be made with the AFV in place? It looked to me as if they cannot. If I remove the AFV to test it, I'll do the "yogurt cup" test to check for a vacuum leak. Might as well while I can. While the wheels are off, I'll do a thorough inspection of the suspension and brakes. Might get the brakes bled, too. I suspect the rear cylinders are leaking, as the reservoir for the rear is low. I already will have to rebuild the MC, as it is leaking out the back against the booster. But that won't happen this weekend. If I get all that done, I'll be pleasantly surprised. My weekends get filled with lots of unplanned activity, lol. Thanks again for the many suggestions. Regards, John.

Wow. That's a lot more work than I had imagined. I never noticed how different the 240 and 280 front ends were. Thanks for sharing.

I haven't had much time to work on it yet. But I fixed the clock. I set it to the correct time and it magically started working, lol. And I got the balky passenger door latch to work properly again. It just needed a little lubrication. I'm almost to the point of removing the AFM, having removed the intake hoses from it. Tonight, I'll dive into the AFM. If I get it running, I'll let it warm up and do an oil change.

For now, I just want to clean it up, get it running and enjoy it as is. I'll explore minor mods to improve engine performance while retaining the FI. I'd like to swap over to 240 bumpers pretty soon. Long term, I'd like to remove the sunroof and the body side molding. But that'll have to wait for a full repaint. It's funny; while I was searching I was thinking about lots of mods to modernize and customize one (lowered, triple webbers, custom interior, etc.). But this car is so original, I feel a bit of obligation to preserve its originality. So I'm going to have to consider my options for a while. I have an introductory thread linked below which might be a more appropriate place for this discussion: http://www.classiczcars.com/topic/53262-new-owner-of-77-280z-from-upstate-sc/