the_tool_man

I didn't know noid lights existed. I'll pick up a set. I didn't check the distributor. But I've already set the static timing. Would it run with the distributor 180 degrees off? Sent from my XT1254 using Classic Zcar Club mobile

FSM spec is .037-.041 for a '77. Five of the new ones I bought were at .038. so I gapped the sixth one the same. Sent from my XT1254 using Classic Zcar Club mobile

Tonight I pulled the plugs, cleaned them and gapped them to .038". I pulled the valve cover and checked the valve lash. All were in spec. While I had it open, I rotated it to put #1 at TDC and verified the cam timing was correct. I checked the torque on the head bolts. They were all tight. Does the red on the camshaft mean anything? Then I buttoned it all back up and started the engine. I pulled each plug wire in succession to see if the idle changed. The idle is so rough that it was hard to tell. But it seemed as though #2, #4 and #5 made a difference and the others didn't. I confirmed with a timing light that all plugs are getting spark. Fuel pressure is good. That leaves injectors and vacuum, right? I don't have a stethoscope (I'll pick one up this weekend). And my hearing is shot. So I've decided to just replace all the injector connectors. I already have new ones, since I'd planned on swapping them anyway (boots are disintegrated). As I said, the injectors are brand new. I practiced connector pin removal tonight at the kitchen table. I also borrowed a fog machine to test for vacuum leaks. I'll play with that this weekend. Sent from my XT1254 using Classic Zcar Club mobile

Thanks for that. I went to Harbor Freight and bought a ready-made remote start switch for $8 (with coupon). Worked great for re-starting while diagnosing running issues, looking for leaks, etc. I also used it for compression testing. But it never occurred to me that I could have left the key off to disable fuel, saving me the trouble of disconnecting the injectors. I was in the habit of turning the key on every time. I guess I deserve to be treated like an idiot, when I act like one.

I'm not sure whether to find this line of discussion funny or insulting. I assumed a photo of the mysterious box was sufficient. For the sake of brevity, I didn't develop an elaborate verbal description. Again, knowing what to call it would have been helpful. But I didn't have that information. I have every intention to resolve the fuel pressure issue at the earliest possible opportunity. I am quite familiar with the fuel pump test you mentioned, and will certainly perform it. But in the event the fuel pump doesn't operate, I will be looking for possible causes, starting with most likely ones. For example, what electrical connections might I have disturbed? Since I touched the junction box, I wanted to know what it does, so that I can assess whether or not it might be related to the issue. The time to ask is now, while there is time for someone to answer, not at 8:30 this evening when I need the answer at hand. I can see how my questions might appear random or spontaneous if they don't correspond with your paradigm of a logical troubleshooting method. But there is an underlying reasoning, nonetheless. Disconnecting the fuel injectors was so that I didn't get sprayed by fuel while performing the compression test. Because I wanted to minimize cooling down during the test, I took out all of the plugs at the same time to get compression readings quickly.

I have tried to identify the mysterious black plastic thing that is screwed to the driver side inner fender forward of the coil. See yellow circle in photo. I haven't found it through searching, since I don't know what to call it. I tried to open it last night while working on the car, thinking it might be a junction box of some sort (trying to avoid having to unplug all of the injectors). I figured out it's potted, and can't be opened. But what is it? If it has something to do with the fuel pump, it might explain why mine quit working. Unfortunately, during the compression testing, I paid no attention to the fuel pressure. So I don't know exactly when it quit.

It's detailed in my intro thread linked in post #1. But the fuel system has been gone through from the filter outward. Fuel pressure was verified. 44psi dead headed to test check valve. 35psi with engine off. 32psi with engine at idle. New FPR. New injectors. New hoses. I haven't replaced the CSV. But I'll check it.

Load test is a good idea. I'll try that. Plugs are new with correct heat range. I'll check gap. Water temp circuit has been verified. I will test CSV. Air filter was removed on day one. FPR has been replaced. Fuel pressure was good. Leakdown was in spec. Fuel check valve tested good. AFM came from running car.

Good idea. I'll check the plug gaps. I still have the old, conventional plugs, though they're really dirty. I could swap those back in if you think they'd be better. Once again, the car will start and idle, albeit roughly, when cold. Once warm, it won't really idle for very long, maybe 15 seconds or so. At any temperature, when I attempt to rev the engine, it will hesitate and pop a few times in the intake. Then it will rev. If I hold it at 2000 rpm or more, it seems to run pretty smoothly, with a slight tremble. I don't know if that's normal or not, since I've never owned one of these before. I have not attempted to drive the car, other than driving it off the trailer and into my shop. The driveway is very steep. And the thought of trying to back it up that hill with it sputtering and dying doesn't appeal to me. I verified spark on all six cylinders with my timing light.

I have lots of pics. The only overall engine photo is from the day I bought the car (below). The coil of wire around the AFM was what I stuck in it to hold the flap open and let the car run well enough to drive it off the trailer and into my shop, lol. That AFM ended up having an intermittent fuel pump contact, and had been "adjusted" by someone. I replaced it with a known good one from a running car. I've included a couple of closer shots of the sides of the engine in case they help. I've got close-ups of just about everything. So just ask if you want more detail.

The boot looks like practically like new. No tears. All the soot has made me think it's running rich. But the popping in the intake has everyone telling me it's running lean. I don't know what to believe. Photo of boot right after I got the car. I've replaced the coil and plug wires since this photo was taken. So disregard the beat up coil wire.

I got one end of the PCV hose loose, so I could give it a good inspection. No apparent issues. I've come up with a plan to use smoke to look for vacuum leaks. But I couldn't do that until a friend brings me his fog machine. So tonight I did a compression test. After warm-up: 1:152psi 2:152psi 3:158psi 4:155psi 5:155psi 6:150psi An 8psi range (5℅) seems pretty good. Here's a pic of the plugs (in order 1-6 left to right): They probably have about fifteen minutes of total run time on them. No time for more than that. So I put everything back together and checked the firing order for the fourth time. Of course there's always something that goes wrong. I have no fuel pressure now. Not sure how since I didn't touch the fuel pump circuit. Sent from my XT1254 using Classic Zcar Club mobile

I did the yogurt cup test months ago. It would build pressure as it should. But it would probably be a good idea to repeat it. I checked the web between the intake and exhaust ports for the EGR. It's solid. I was careful to clean the surface of the intake manifold so the new gasket wouldn't leak. I did not plug the pipe from the exhaust. So I wanted to make sure neither side would leak. I tried double nutting the studs. But this required using an open end wrench to loosen them, which put a lot of bending on them. The extractor I borrowed uses cam driven rollers to grip the stud all around. I put a big ratchet handle on it and pulled pretty hard to the point where I think I yielded the studs a bit. In another thread I detailed my ordeal with snapped fuel injector screws. Rather than break these, I used the EGR spacer to let me put nuts on the existing studs. At some point I'll use heat to get them loose. But I'm moving on for now. Timing is 10 deg. BTDC at idle. Vacuum advance seems to be working. But working alone I can't reliably correlate rpm and timing. Sent from my XT1254 using Classic Zcar Club mobile

I picked up a gasket and made a block off plate for the EGR. I used a borrowed stud remover to try getting the studs out. But they wouldn't budge. Rather than break them off, I decided to just use the old EGR spacer on top of the block off plate. No change in running, vacuum reading, etc. I found the PCV hose under the intake. But I'll need double jointed elbows to get to the thing. I'll go at it from below on my next foray. But I ran out of time tonight. Sent from my XT1254 using Classic Zcar Club mobile

My methodology at this point is to take the list of possible causes provided by the contributors to this thread, and eliminate them, starting with easiest first. Vacuum leaks seem to be most likely, and with the exception of an intake manifold gasket leak, would seem to be easiest to check. Then I'll test the CSV. Next is a compression test. Then valve lash, timing chain, etc. I chose measuring vacuum at the booster line specifically to isolate possible diaphragm failure. I also tested the check valve while I was there (it's working). Engine RPM was at idle. But I couldn't see the tach while I was doing it. I'd guess 750 RPM. When I revved it, vacuum increased as expected. But I didn't attempt to correlate vacuum with RPM. I didn't mention it because it didn't seem important. But the EGR valve is really dirty. The pintle moves freely under finger pressure. But I can't tell if it seals when closed. I can't really test it until I have a block-off plate made to cover the openings in the intake. Then I can hook it up and visually test it if I want to. If the pintle moves with vacuum, I could attempt to clean it. But the plate will eliminate it as a cause for now. I don't have anything else to report. Between work, family and other obligations (including the death of a friend), I've only had about 30 minutes with the car in the last several weeks. I should get more testing done this week. Plans today include borrowing a stud extractor from a friend, picking up an EGR valve gasket. If time allows this evening, I'll make a block-off plate.

I'm giving serious consideration to stripping down the entire intake and getting rid of all the emissions junk, if for no other reason than to eliminate a bunch of potential problems. But that's for another thread.

Quick update. I used the vacuum line from the brake booster to check idle vacuum. It's below 5" at idle. So I have a big vacuum leak. I've checked all of the hoses for obvious leaks. So I decided that before I start replacing all that mess, I'd pull the EGR valve. It was a welcome relief to break the nuts loose without breaking off the studs. A first, I think! My EGR has a thick cast spacer, necessitating long studs. They're stuck, of course. I plan to pick up a new EGR gasket and make a block-off plate. If this isn't it, I'll just replace all of the vacuum hoses and go from there. Sent from my XT1254 using Classic Zcar Club mobile

I started a new thread for the engine diagnosis. I don't plan to update this one any more. http://www.classiczcars.com/index.php?/topic/56998-Engine-rough-running---at-wits-end EDIT: For the sake of closure, the engine runs now. Turns out I didn't properly seat the #5 fuel injector seal when I replaced it. This caused a huge vacuum leak which was causing most of the issues. See above linked thread for details.

True. I plan to make a block off plate to eliminate that as a cause. Sent from my XT1254 using Classic Zcar Club mobile

I didn't have much time to work on the car tonight. But I had a few minutes to poke around. The EGR/BPT recall has been done on my car (see photo of sticker). I used a mirror and looked under the intake. I didn't see any holes; not even any surface corrosion. I picked up a remote starting switch, too. It'll come in handy for compression testing. Sent from my XT1254 using Classic Zcar Club mobile

What's a BPT tube? Found pics of what you're talking about in your reply to G3BOWSKY's thread on popping noise. Thanks! Sent from my QTAQZ3 using Classic Zcar Club mobile

Not yet. They've probably got about ten minutes of running on them since I installed them. Sent from my XT1254 using Classic Zcar Club mobile

Used from a running car. Sent from my XT1254 using Classic Zcar Club mobile

Early on, the CTS circuit read super high resistance. It may as well have been unplugged. When I corrected it (new sensor and cleaned bullet connectors), it didn't noticably change anything. But I was having fuel delivery issues at the time (bad AFM contacts), so that might have masked the issue. It's something to try. Sent from my XT1254 using Classic Zcar Club mobile

No. That sounds like fun. Sent from my XT1254 using Classic Zcar Club mobile