|Topic Review (Newest First)|
|11-27-2017 07:55 AM|
|chairmankaga||Just boosting this thread to say thanks to everyone who helped, because the car is running like a champ and I've been able to put several hundred miles on the clock these past few months, including some pretty hard driving out in the Hill Country, without so much as a hiccup (once I replaced the AAV with a manual heater core valve, I mean). I've pushed timing several degrees with great results, and even the idle is smooth and even. A couple of old-timer ALfa guys stopped by a few weeks ago and helped me dial it in a bit, and everything seems to be solid. November & December in Central Texas is prime windows-down driving weather so I plan to use the time wisely. Thanks again!|
|06-08-2017 10:31 AM|
|Del||Congrats. Glad you didn't give up.|
|06-06-2017 07:58 AM|
|shrike||Happy to hear that it's running again!! For me the most useful part what the comment that "I even got my wife to help" -- this morning I told my wife that I learned from alfabb that when all else fails, bring in the big guns.|
|06-06-2017 07:03 AM|
Yeah, I'm residing in just as much disbelief as you regarding the supposed culprit. It doesn't make sense! Maybe there was an additional obstruction in the hose or adapter? Maybe it was some weird principle of hydrodynamics? Maybe I coincidentally leaned the right way over a wiring connector and brought it back to life?
It was utterly bizarre. After GMJohns helped me with the distributor wiring orientation the thing still wouldn't start, which is why I decided to try one last thing before towing it off to a shop - recheck the injectors. I suppose it's also possible there's some debris in the fuel rail and lifting it out and plopping it on its side to check the spray patterns was enough to dislodge it? If the problem comes back I think I'll know where to look.
But the gauge and adapter were straight from Summit. Basic anodized aluminum 5/16" gauge adapter with a 100 psi gauge that just screws in. Like I said, it protrudes into the adapter maybe a 1/4" or so, and maybe that's enough to do whatever it might have done? I could shim it with a nut to back it out a bit.
Anyway, weird. One for the ages. Moral still applies though! "If it don't run, think, 'What was the last thing I ****ed with?' and that's probably it."
|06-05-2017 11:29 PM|
|martym00se72||Nothing like a happy (ish anyway...) ending. Bet that seems like a weight has lifted from you! This is good news!|
|06-05-2017 11:02 PM|
Originally Posted by chairmankaga View Post
I would like to see details/pictures of your exact fuel pressure gauge setup---it would take quite a small restriction to obstruct fuel flow to the extent of stalling an engine with no load!
We have at least a half-dozen different fuel pressure gauges at my shop of varying ages and manufacturers; I have used them all on many different types of cars over the years and have never had one cause a restriction or other issue when installed in-line with the fuel inlet, even while test-driving the car and monitoring fuel pressure under load.
Take a breather, hug your family, and get back to us when you can!
|06-05-2017 08:19 PM|
|alfaloco||After what you and that car have been through, I think you hit the nail on the head.|
|06-05-2017 02:08 PM|
I guess I don't get how that could happen. My '82 has 4 marks - M (max advance), PF (cam and static timing) share a mark, and R (full retard at idle). The cams should be timed to the PF mark, and they're RIGHT on it. Both cams, aligning the mark on the shaft with the cap, as well as the crank. Spot on. I pull the retard vacuum line to the diaphragm and it speeds up. I let it more air and it speeds up. I close down the idle and it slows down. I hook up the retard line, rotate the distributor to bring the pin to the correct mark, following the instructions, balance the idle (it's a give and take to get the idle to 900-1000 AND get the mark aligned at R), and it starts to choke and stall.
Maybe it's a mixture issue?
But what if the car just likes the advanced timing? No pinging, no missing, vacuum indicates a healthy motor... Weird, huh? I've read about other cars with the early V6 liking advanced timing too, so maybe it's just one of those quirky Italian idiosyncrasies. Pay no attention to the specs. Does it sound good? Does it drive well? Then leave it alone.
|06-05-2017 12:47 PM|
Normally, having to advance (or retard) the distributor excessively to get your timing right indicates you are a tooth off on the timing, meaning the drive pulley at the timing belt. In the case of this V6, where you have a drive tang in place of a gear, it tells me the auxiliary drive shaft is just a tad off.
BUT-- in the case of this motor... I could be wrong (and have been!).
|06-05-2017 12:03 PM|
|chairmankaga||Man, it was like a cascade of failures. I still don't know why the ignition has to be SO advanced to run though. I'll pump in some 93 octane to help with predetonation so I can at least get it to a specialist who can help diagnose that. I'll get in some more simulated miles int he garage this week, then maybe tool around the neighborhood a bit, then venture out to the mechanic for that work.|
|06-04-2017 07:25 PM|
|alfaloco||Well how 'bout them apples! Once you moved past the ecu and AFM I got a feeling you were dealing with not one, but multiple problems. Amazing... wish I could have been there.|
|06-04-2017 03:41 PM|
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|06-04-2017 03:22 PM|
Wanna know what I did? Aside from reversing the wiring from the distributor? That was causing the total non-start situation. But to solve the start/stall that's been the actual issue for months?
Removed the fuel pressure gauge. I even got my wife to help. I've noted that my fuel pressure had been fine, according the the gauge installed before the rail. I went ahead and pulled out the rail, disabled the coil, and cranked the engine to make sure each injector was firing and/or not sticking open. I'd done this check previously, but after watching several videos on what a healthy injector pattern should look like, I concluded mine looked WEAK. Just on a whim I replaced the gauge with a new segment of FI hose, and the injectors were spraying much more vigorously. I suppose the nipple for the gauge was somehow obstructing fuel flow without spiking the pressure? I noted it was protruding maybe 1/8" through the adapter. Anything is possible I suppose. Butt that's all I did. Removed the gauge, and the car ran.
And it ran the car for a good 15 minutes just now!
I do still have a problem though. I have to run the ignition fairly advanced with a fast idle (1500-ish warm) to keep vacuum up and idle steady. I'd say it's halfway between the P and the M marks. Maybe I just don't have the idle and timing balanced out yet? As jacked up as everything was I assume that's likely.
I did fry my new MSD coil and am using my original one without the ballast resistor. I'm also running a replacement ignition amp, although I'll try the solid state replacement I'd been using before committing to buy an original-style Bosch part. Some wiring needs to be cleaned back up, which I'll save for next weekend. For now I just want to bask in the knowledge that it's running. After hundreds of posts it was something seemingly dumb and arbitrary, although the actual reason I started this thread might NOT be resolved. More to come.
Moral: My friend's dad was an old Air Force mechanic during the Korean War. After he retired from the military he had an auto shop until he died about 10 years ago. His advice to us, when we started to tinker, was simple, "If it don't run, think, 'What was the last thing I ****ed with?' and that's probably it." Even something as arbitrary as a fuel pressure gauge (and I'm still not saying definitively that was my problem, but if not it sure is a coincidence that it ran after I removed it).
|06-04-2017 03:14 PM|
|06-04-2017 03:06 PM|
Good luck, sounds like you are on to something.
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