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| Help! https://www.slantsix.org/forum/viewtopic.php?t=14722 |
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| Author: | 66bcuda [ Mon Oct 17, 2005 10:15 am ] |
| Post subject: | Help! |
My Barracuda is currently "stranded" at my friends in Fairfield.... The Short version: Starts up flawlessly, Idles smooth, can rev as high as I want to take it, but when it's on the road it chokes out while under load. The longer version: This engine was rebuilt 500 miles ago. The 1 bbl B&B carb was rebuild last week. The coil was replaced last week. The fuel pump was replaced last night. The rotor and cap were replaced last night The timing was originally set to 0 deg, but yesterday AM we put it at 5deg ATDC This car was purring down the road at 70 all day with no issues, I crossed the Benicia bridge and about 1/4 mile later it started acting like it was running out of fuel. The gas gauge is still non-op, so we've been tracking milage. based on the old milage (before timing change) we estimated we should be 10.5 gallons from full. i rolled to a station at 10 mph, and filled it. It only took just over 9 gallons (yeah better milage!) the symptoms: It will always start and idle smoothly I can get through first most times but just into 2nd gear it starts choking. When i take my foot off the gas it smooths right out. once the "load" has been reduced I can give it gentle gas and it will go a bit more before choking out again. ideas? Steve |
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| Author: | SlantSixDan [ Mon Oct 17, 2005 10:42 am ] |
| Post subject: | Re: Help! |
Quote: :The 1 bbl B&B carb was rebuild last week.
OK, that's a possible place to look for the problem. Sounds like you've got a serious lack of fuel under any kind of load. Perhaps not all the crud was cleaned out of the carburetor, and there's some still left in the main metering circuit. Or, perhaps the aluminum step-up piston is stuck in its bore, or the rubber O-ring was left out, or the spring wasn't properly installed, or the step-up rod has fallen off the piston.Quote: The timing was originally set to 0 deg, but yesterday AM we put it at 5deg ATDC
H'mmm...you went from "too retarded" to "way too retarded". Why? 5°BTDC would be an appropriate starting point.
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| Author: | 66bcuda [ Mon Oct 17, 2005 11:00 am ] |
| Post subject: | |
hmmmm.. the 66 factory manual says 225 with CAP should be at 5 ATDC.... It did smooth out as well. so it should be 5 BTDC??? The manual also ID's one of the possible issues with a loss of power to be incorrect timing... is is possible that this 5dg ATDC could be the cause? We'll definately check out the carb again.... I was really confused by the fact that i can get 3-3500 rpm constant without load....but with load even at a lower RPM it chokes out.... I'm borrowing a toyota trunk to be at work here in SJ. I'm not sure when we're going to be able to get back to fairfield to work on it again, but I will update when we do.... Thenx, steve |
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| Author: | argentina-slantsixer [ Mon Oct 17, 2005 11:22 am ] |
| Post subject: | |
not an expert on carter carbs, but seems to me that SSD is right on the money with his suggestions (I second that). And I myself never saw any kind of vehicle specs with initial timing ATDC... never ever. I've seen zero initial advance cars, but never retarded past TDC. |
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| Author: | dakight [ Mon Oct 17, 2005 11:30 am ] |
| Post subject: | |
I scanned quickly through the above replies and didn't see mention of the fuel filter. What you are describing are the classic symptoms of a clogged fuel filter. |
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| Author: | SlantSixDan [ Mon Oct 17, 2005 11:31 am ] |
| Post subject: | |
The ATDC ignition timing settings were applicable when these cars were new and still had their original CAP distributors and carburetors, and the "green weenie" distributor vacuum control valve was still in place and working. The idea was to retard the timing at idle, which would require a relatively large throttle opening to provide a normal idle speed. The larger throttle opening allowed more air in, for a cleaner burn at idle (and a "Pass" result on California's early emission tests). The CAP distributor and "green weenie" valve were set up so as to advance the timing back up towards normal levels above idle. Getting them to do that was a delicate and tricky operation when everything was brand new. Forty years later...??! Not gonna happen. I don't think your ATDC timing, on the other hand, is causing the flameout effect. I think that's a fuel problem. |
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| Author: | 66bcuda [ Mon Oct 17, 2005 12:10 pm ] |
| Post subject: | |
Thanks for the clarification on the CAP issue. Although this is the stock distributor and most everything else is still original, i'll take your advice. So, the timing should be set at 5deg BTDC? Sorry bout that, Yes, the fuel filter was replaced at the same time as the carb was rebuilt. There is "crud" in the filter, but it seemed to flow ok... It's one of the original glass ones with the magnet ring in it. I'll pull that off and clean it out as well. Another thing that I left out (as my lady pointed out) is that at the point we gave up last night (O'dark thirty) Heather noticed that when she turned off the flashlight she saw some pale "st. elmos fire" along the plug wires where they touch the fenderwell..... even saw a couple sparks at the coil + and - terminals... (we're bringing new wires up with us) Thanx again for all the help... last night was SOOOO frustrating after it was running So smooth. Steve and Heather |
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| Author: | SlantSixDan [ Mon Oct 17, 2005 12:23 pm ] |
| Post subject: | |
Quote: So, the timing should be set at 5deg BTDC?
Give that a try.Quote: Sorry bout that, Yes, the fuel filter was replaced at the same time as the carb was rebuilt. There is "crud" in the filter, but it seemed to flow ok... It's one of the original glass ones with the magnet ring in it
There are no "original" glass fuel filters. The originals were like the proper replacements: Metal shell.Quote: she saw some pale "st. elmos fire" along the plug wires where they touch the fenderwell..... even saw a couple sparks at the coil + and - terminals
Overdue for new wires.
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| Author: | 66bcuda [ Mon Oct 17, 2005 12:30 pm ] |
| Post subject: | |
not originally the glass one... hmmmm. OK Learn something new every day.. Are there issues with the glass ones? I like the magnet and the ability to see through it, but if there are quality/reliability issues, i'll go the the metal one. (is the Fram G2/G12 plastic one a good substitute for the metal one?) Steve and Heather |
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| Author: | SlantSixDan [ Mon Oct 17, 2005 1:00 pm ] |
| Post subject: | |
Fram: Never on my car. Cruddy quality. Plastic fuel filters: I don't trust them with today's more plastic-aggressive fuel formulations. Glass filters: Breakage/fire risk. Maybe just theoretical, but...! If you get a chance, do the Fuel line mod and filter relocation. |
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| Author: | 66bcuda [ Mon Oct 17, 2005 1:41 pm ] |
| Post subject: | |
I was not aware of the Fram=cruddy issue. So what brand is recommended? The fuel line relocation makes good sense. thanx for that as well Steve |
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| Author: | mcnoople [ Mon Oct 17, 2005 2:16 pm ] |
| Post subject: | |
Don't know about fuel filters, but the slanted crazies of this board will generally recommend using a wix or napa oil filter. I've used many a fram without problems, but I change my oil about once a month(1,000 miles) and use a flush every other oil change. Currently I am using a wix and will prolly continue to do so. The theory is that fram uses a inferior anti drainback valve (if my memory is working right) and the oil passages in the filter are dramatically smaller than a wix/napa filter. Generally fram uses the cheapest part available approach that so many other companies have adopted. |
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| Author: | emsvitil [ Mon Oct 17, 2005 2:30 pm ] |
| Post subject: | Oil filter study......... |
see http://minimopar.knizefamily.net/oilfilterstudy.html which is the complaint about fram oil filters. |
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| Author: | emsvitil [ Mon Oct 17, 2005 2:34 pm ] |
| Post subject: | clear fuel filter...... |
I have a glass one and don't see any problem with it......... It's not in a location that can bang against anything to break. I put it in to see what my problem was when my fuel filter was clogging up very very quickly (fuel tank rust). Plus I could take it apart and clean it.....  I subsequently added an oil-filter to use as a fuel-filter to solve the rust problem............. |
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| Author: | mrmopar64 [ Mon Oct 17, 2005 9:10 pm ] |
| Post subject: | |
One other thing you might look for is a bad hose before the pump where it could be sucking air......... If you have the glass filters start it and watch for air bubbles in the filter if you see bubbles you have a leak that filter should fill up and you should see very little fuel movement We chased a similar problem for days before we found the bad hose It was split on top so it didn't drip gas but was the problem of course after carb and pump change MM64 
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