60s GM Fan Posted October 26, 2021 Share Posted October 26, 2021 Okay so my 67 430 runs well when I'm driving but it'll sputter/stall at a light or sometimes in park. I noticed it does appear to be running a bit rich. Is this a mixture issue or something else? I noticed that I have one of those metal fuel filters in between the fuel pump and the carburetor and I know those can be problematic sometimes. Any advice is greatly appreciated. Link to comment Share on other sites More sharing options...
avgwarhawk Posted October 26, 2021 Share Posted October 26, 2021 Start with the basics. For me, I would look at the gap on the points. Check for any vacuum leaks. 3 Link to comment Share on other sites More sharing options...
JohnD1956 Posted October 26, 2021 Share Posted October 26, 2021 Besides what Chris suggested I would add to check the spark plug wires. They do seem to deteriorate early especially if a car was sitting around for a long period of time. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted October 26, 2021 Author Share Posted October 26, 2021 All great suggestions but everything under the hood is essentially new or rebuilt. Link to comment Share on other sites More sharing options...
avgwarhawk Posted October 26, 2021 Share Posted October 26, 2021 1 hour ago, 60s Buick Fan said: All great suggestions but everything under the hood is essentially new or rebuilt. Does not mean the ignition parts are good. What was rebuilt? Engine? Carb? Both? Ran ok after the rebuild then started acting up? 1 Link to comment Share on other sites More sharing options...
dmfconsult Posted October 26, 2021 Share Posted October 26, 2021 I would check the pressure you are getting out of the fuel pump, as it's not unheard of that the newer ones fail out of the box. I would also examine that extra fuel filter, as there was not one there originally. It may be restricting fuel enough to cause some vapor lock symptoms. I had a similar problem develop on my 67 Electra. One solution was to install an electric fuel pump and filter along the frame rail to "assist" the manual pump, and that helped, but I was still getting some symptoms similar to yours. We finally dug into what was a recently rebuilt carburetor and found that the gasket used under the air horn was missing a tiny piece which caused an air leak under certain conditions. With the right gasket in there the problem was solved. I technically didn't need the electric fuel pump but I've left it on for now. Link to comment Share on other sites More sharing options...
dmfconsult Posted October 26, 2021 Share Posted October 26, 2021 Also, how old is the fuel? I know you just got the car, but is it still running on fuel that was put in by the previous owner? I wonder if it's older ethanol blended fuel that is causing your issues. 1 Link to comment Share on other sites More sharing options...
carbking Posted October 26, 2021 Share Posted October 26, 2021 A fuel filter issue would cause problems at cruise, not at idle. Not saying this is your problem, but we have had many prospective "carburetor" customers relate the same symptoms. My first question is always "have you or someone else installed an electronic conversion in the distributor? If so, upgrade to points and condenser". The upgrade fixes LOTS of these issues. Cannot recall when someone called me with electronic conversion issues at cruise, always at idle. Jon 1 Link to comment Share on other sites More sharing options...
Wayne R Posted October 26, 2021 Share Posted October 26, 2021 (edited) Agree with Chris--start with basics--especially with points and condenser , many times i have found that previous supposedly good mechanics have changed electronics but not correct. Always do electrics first then go to fuel and other items. .What happens alot is the points can actually close up because of no lube on distributor cam over years, and end up with a gap of from 5 to 8 thou, this causes alot of problems as it developes pits and holes in points , so condenser can not do its job correctly--always change both points and condenser. Like John said check spark plug wires, and advance system on distributer and vacuums. Edited October 26, 2021 by Wayne R (see edit history) Link to comment Share on other sites More sharing options...
60s GM Fan Posted October 26, 2021 Author Share Posted October 26, 2021 Thank you for the advice so far. Doug mentions that the extra fuel filter wasn't there originally. Was there any filter in place then? I'm not a fan of these canister filters as they have a tendency to impede the flow of fuel. Link to comment Share on other sites More sharing options...
dmfconsult Posted October 27, 2021 Share Posted October 27, 2021 The only filter on my 67 Electra originally (other than the sock on the fuel sender in the tank) was in the fuel inlet in the carburetor itself. When I had my sputtering at idle issue that was the first thing I checked and it was clean, but I changed it anyway. By the way, I run the original points set up and I also changed those and the condensor out, along with the cap and spark plugs and that made no difference. I do agree though, if you run an electronic replacement for your points, to go back to points and see if that helps. Link to comment Share on other sites More sharing options...
NTX5467 Posted October 27, 2021 Share Posted October 27, 2021 With all of the glory sung (in former forum posts) about the Pertronix electronic ignition replacing ignition points, I find it interesting that an "electronic ignition conversion" would cause an idling issue. FWIW What I CAN mention is that there should be some special "point grease" which should be applied to the rubbing block on the point set so that the rubbing block will not wear before its time (used to be about 12-15K+ miles, back then). When it wears, the point gap and related "dwell" reading will change, which will also affect the base ignition timing, which when not correct, might contribute to the idling issues you mention. Check and adjust the DWELL to spec, FIRST. Then set the base timing SECOND. Then adjust the idle mixture screws and hot idle speed screw, if needed. If the distributor has the "window", you can adjust the points with an Allen wrench with the engine running (very convenient!). I had an issue on my '68 LeSabre 350 with it intermittently and randomly dieing, even while running on the Interstate. If I could "catch it before it died", I could wildly pump the accel pedal and it would keep running. When it happened one night on the way to my shadetree shop, I decided it was time to do something. I noticed the fuel pump was moving as the engine was running. Not knowing how old it was, I figured that was a good place to start. Changed the pump, started the engine, and it ran/sounded better than it ever had since I got the car. So, end of problem. I'd already done the plugs, wires, and such. Generally, if the car is runing so rich that it will not stay idling, there should probably be black smoke coming from the tail pipe. With the spark plugs having soft, black soot on them, too. The common fuel filter is the one in the carb fuel inlet. The OEM could have been a paper element fuel filter, but the common one was the gold "rock" filter. To me, they should be more prone to clogging than an external "can" filter, due to their smaller size and surface area. FWIW One check . . . with the car hot and idling, when it starts to die, let it die. When it does, remove the air cleaner assy and see if the accel pump has any output when you move the throttle level. Usually, you can hear the pump either sputter, pump fuel, or pump air, by observation. This test will determine if you have a fuel supply issue. ALSO check to see that the gas cap is correct for the car! NOT to forget to check/replace ALL of the rubber fuel line hose in the system, front to back. Ethanol'd fuel deteriorates the rubber from the inside out, so that might be an issue/flow restriction, too. Hopefully, when this issue is fixed, you can confidently enjoy the car. Just some thoughts and observations, NTX5467 2 Link to comment Share on other sites More sharing options...
Oldtech Posted October 28, 2021 Share Posted October 28, 2021 Nobody has mentioned what I feel is obvious. Try adjusting the idle mixture screws. 67 should have no caps. Link to comment Share on other sites More sharing options...
Frank DuVal Posted October 28, 2021 Share Posted October 28, 2021 (edited) On 10/26/2021 at 9:54 PM, NTX5467 said: I find it interesting that an "electronic ignition conversion" would cause an idling issue. FWIW Well known and documented issue with Pertrtonix Ignitor II on low idle cars, like a Powerglide Corvair. On 10/26/2021 at 9:54 PM, NTX5467 said: but the common one was the gold "rock" filter. To me, they should be more prone to clogging than an external "can" filter, due to their smaller size and surface area. FWIW I agree, and that's why I install inline filters where they are hidden, not on top of the engine. I know, harder to change, some locations drain the fuel tank on you while changing them😲, but cleaner install with no extra rubber fuel line on the engine. WIX 33032 for 5/16" lines, 33033 for 3/8" lines. Sure, metal, can't see inside, but no leaks from all the separate sections of the aftermarket glass type.😉 On 10/26/2021 at 6:17 PM, dmfconsult said: I would check the pressure you are getting out of the fuel pump, as it's not unheard of that the newer ones fail out of the box. True! And pressure too high is a common issue. The spring rate is too high. To those that do no know, the spring is the item that makes the output pressure. The cam link does NOT produce output pressure, it just causes the pump to suck fuel in. Old vacuum gauges had a fuel pump pressure section, just connect the rubber hose to the output line of the fuel pump (might take some creative rubber hose /adapter work) and crank the engine a few revolutions. Specifications are in the shop manual for hour car. Since the car runs at cruse, I would not check volume specification. Edited October 28, 2021 by Frank DuVal (see edit history) 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted October 29, 2021 Author Share Posted October 29, 2021 It worked great this morning when it was cooler. Tonight...she was picky but got me home. Link to comment Share on other sites More sharing options...
EmTee Posted October 29, 2021 Share Posted October 29, 2021 So, better when cold(er)? Does it have a choke pull-off (vacuum diaphragm)? If so, is it working, or is it leaking vacuum? 2 Link to comment Share on other sites More sharing options...
avgwarhawk Posted October 29, 2021 Share Posted October 29, 2021 19 hours ago, 60s Buick Fan said: It worked great this morning when it was cooler. Tonight...she was picky but got me home. Check the choke operation. 1 Link to comment Share on other sites More sharing options...
60s GM Fan Posted October 30, 2021 Author Share Posted October 30, 2021 I think it might be the mixture plus choke. Shes going in for service next weekend. Link to comment Share on other sites More sharing options...
60s GM Fan Posted November 8, 2021 Author Share Posted November 8, 2021 Problem was found. The carb needs a rebuild as the primaries are dumping fuel at idle/park. Carb kit has been ordered and it'll be installed here within the next two weeks. 1 Link to comment Share on other sites More sharing options...
JohnD1956 Posted November 9, 2021 Share Posted November 9, 2021 beware that the float in the Quadrojet's can have issues and that new floats are available. Unless your carb kit has a new float you may want to look at Quadrojetparts.com. They have plastic and brass floats available. 3 Link to comment Share on other sites More sharing options...
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