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By Gary - 14 Years Ago
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I'm looking to find someone that I can ship my 57 Distributor to for timing advance check/repair or adjustment. With the timing light and vacuum line connected the timing advances when rpms are increased. However, under driving conditions there seems to be a hesitation pefore the engine accelerates. Timing is set 10 deg BTC but I have tried higher and lower settings with no improvement. No vaccum leaks and carb has new rebuild kit. If I could just eliminate the distributor as a problem it would be great. Please give me a couple of recommended service sources. Thanks. Gary
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By oldcarmark - 14 Years Ago
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What carburetor do you have?If you apply direct vacuum to the advance unit at idle does the timing advance?In other words is the vacuum advance working?Was this a problem before the carb was rebuilt?Are the timing marks on the damper accurate(damper hasnt shifted)?Before you send the unit out you might want to do a couple of basic tests.
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By Pete 55Tbird - 14 Years Ago
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Gary, What Mark is saying is that your distributor has TWO FORMS OF ADVANCE. A mechanical advance that is a function of engine RPM and a vacuum advance that is in addition to the mechanical advance. At low vacuum level( weather from ported or unported source) there will be little or no vacuum advance. A car can operate just fine with only mechanical advance and some high performance race engines do. Your vacuum advance diaphram might be torn and if so you will not get advance at light throttle, steady cruise speed but this vacuum HAS VERY LITTLE to do with what you are trying to correct. A flat spot or hesitation on heavy throttle acceleration. THAT IS ALL DUE to the MECHANICAL ADVANCE along with the CARBURATOR. Before anyone here can help you solve your problem YOU will have to realize we don`t know what the problem REALLY IS UNTIL YOU EXPLAIN IT MUCH MORE FULLY. At this point it could be almost anything. Pete
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By joey - 14 Years Ago
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You mentioned that your carb was rebuilt...this might mean something in there might yet need to be fine tuned. First thing I'd do is make sure the accelerator pump is working properly. When you accelerate the throttle linkage, are you getting an IMMEDIATE visible pump shot? Smooth stream? That low end hesitation you describe is a fairly common occurrence, and this can often be the source. It's important to try to isolate (and eliminate) possible causes one at a time. I'd try to ensure the carb is OK first. Also check for a vacuum leak.
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By oldcarmark - 14 Years Ago
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The reason I ask what carb you have is that if it is a a Teapot carb there is hesitation in the carb itself.This was a problem right from new.Some of the better carb rebuilders have been able to improve on them.It does sound to me to be more of a carb problem than a distributor.
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By Talkwrench - 14 Years Ago
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I agree with Mark,Sounds like your carb to me. You had better tell us what you have on there. Just make sure you check your points, dwell etc too.
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By Talkwrench - 14 Years Ago
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Check your float level again !!!
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By Gary - 14 Years Ago
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The carburetor is on a 57 Ford 4 bbl intake. The carburetor is a Holly with 80457-3, 0974, stamped on the choke horn. The carb was used but like new when I purchased it. I did have the same problem before the carburetor was rebuilt. The damper/timing marks are correct. While checking the timing and reving the engine with vacuum line attachhed the timing did advance and looked normal to me. However, at idle, when reconnecting the vacuum line the rpms did not increase leading me to think the vacuum advance on disrtribuitor is defective ... thus I would like to send the thing to an expert. Thanks everyone ... very helpful and much appreciated. Note: for those of you helping me with high oil pressure on rebuilt 292 (80pounds at operating temp, 60 MPH), the new oil pump was ok with overflow spring and everything looking good. Put the old, very used, oil pump back on and now have oil pressure of 58 at highway speed and 15 to 20 at idle. Engine has 500 miles since rebuild. Am I OK?
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By pegleg - 14 Years Ago
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Gary, If the distributor is connected to a PORTED vacuum connection (on the carb) it will not advance at idle. A ported vacuum connection has the origin ABOVE the throttle blades. This type will only add advance during cruise conditions when the throttle blades are open. To test this, disconnect the vaccum hose to the carb, bring the engine revs up to about 2000 or so then connect it and watch your timing light or listen for the RPM to increase as you connect it.
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By oldcarmark - 14 Years Ago
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On my first post I did mention applying (direct)vacuum at idle and see if timing changes.If you simply get a piece of hose and hook it onto the vacuum outlet on dist and suck on it you will know very quickly if the advance pot has a hole in it.If you get resistance when applying vacuum the pot is likely OK.There is a diaphragm inside the pot which sometimes gets a hole in it.At what speed are you getting the hesitation-as you initially start to move from dead stop or at a higher mph?
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By Gary - 14 Years Ago
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I had the distributor connected to "ported vaccum." Also, as suggested herein, I sucked on the distributor vaccum line and got great resistance. Did not remove dist cap to see if anything was moving. Moved vaccum connection to bottom of carburetor, this will probably solve my problem! On vacation now and unable to test drive. In case my trouble ends up being the distributor, please recommend someone that I can ship this thing to for adjustment. Thanks to all so much .... you have been a great help to me.
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By Grizzly - 14 Years Ago
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Gary, I think you still have the incorrect vacuum source. I think your carb is a 600 holley the timed vacuum source is a small tube on the right side of the carb coming out of the fuel metering block. Cheers Warren Adams
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By oldcarmark - 14 Years Ago
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The one from the metering block is the "ported" or timed vacuum sorce above the throttle plate.Only becomes active off idle when the throttle plate opens.The one below the throttle plate which is where he has plugged his line onto now is the active,non ported,fulltime vacuum source.If you do a search for this topic in previous posts you will see there are lots of opposite opinions about which source is the one to use.
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By Gary - 14 Years Ago
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OK, I sucked on the distributor vaccum line and got firm resistance (no hole, rips, etc.). I did have the vaccum line connected to the top vacuum connection on the carburetor which was wrong! So, I moved the vaccum connection to the one on bottom of the carburetor and I'll test it tomorrow. That was probably my problem. Thanks to all of you for your answers and help ... very much appreciated
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By oldcarmark - 14 Years Ago
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You are not trying to apply 14 inches of vacuum.All you are doing is sucking enough to verify there is no hole in the diaphragm.If you want to check HOW much vacuum advance you have available apply a direct vacuum source like from the motor and see HOW much the timing advances when direct vacuum is applied.
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By Gary - 14 Years Ago
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For some reason I never saw your email offering to scope my distributor. I am very interested in you doing that. If you are still willing to scope the distributor please send me your name, direct email address, and street address. Also, I'm interested in purchasiing that old (57) rebuilt distributor you mentioned. Thanks, Gary Adams gadams2@bellsouth.net
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