colbysunday 10 Report post Posted January 21, 2014 I've recently received a '69 Mustang Coupe all original with a 302. It was sitting for a few years with about a quarter of a tank of gas in it. Gas is most definitely bad. I was able to get her started a couple weeks ago after getting a new Optima Redtop and I filled the tank with premium gas and fuel injector cleaner (bad idea?) It was running decently though when I drove it to the gas station, a little rough at first. I had to change out the alternator, solenoid, and the v belts. I've changed oil, and all other fluids besides gas so far. I also changed the spark plugs and bled the brakes. After all that, the second journey around the block was a lot more rough. I would press the gas pedal to the floor and it wouldn't really accelerate and would only get up to around 50 or so and it keeps stalling when I'm at a stop. Any ideas on what my next step should be to get this thing running smooth would be greatly appreciated. Could it be the spark plugs are spaced incorrectly? Could I have crossed one of the plug wires? Is the gas being bad affecting the acceleration? Maybe fuel pump is bad? I NEED YOUR HELP! Quote Share this post Link to post Share on other sites
fordguy69 24 Report post Posted January 21, 2014 Start with your fuel filters, the one in the engine compartment and the sock in the tank, likely both of them are clogged. Also see if your carb has a screen at the inlet. Quote Share this post Link to post Share on other sites
Big Secz 26 Report post Posted January 21, 2014 Step 1: Check the fuel filter. Step 2: Blow out the fuel lines. Step 3: Check the carb. Maybe find someone with a spare carb you can swap and test it out. Step 4: Fuel pump. It's all about process of elimination and verifying things are okay before you start spending money. A buddy of mine restored his 69 and had a stalling issue. He chased his tail and threw money into replacing parts only to discover it was a clogged fuel filter. Once you can verify the fuel components are okay, move on to the electrical components. Step 1: Check the spark plugs to make sure they aren't fowled and the gaps is set properly. Step 2: Double check the plug wires are hooked up correctly. Step 3: Check the dizzy, inspect cap, points, and rotor. Step 4: Check ignition coil. Step 5: Check the ignition switch. If that's okay, move on to the vacuum. Keep in mind I'm not mechanic, and others may have better advice, but this is just what I've learned over the years after making mistakes of needlessly hemorrhaging money. Quote Share this post Link to post Share on other sites
Flanders 46 Report post Posted January 21, 2014 I'd be inclined to check the electrical stuff first (in Big Secz's post above), as it's fairly quick and not too messy :) If all that checks out, then go with the fuel delivery system. Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 21, 2014 Thank you guys for all of the advice thus far! Quote Share this post Link to post Share on other sites
jmlay 80 Report post Posted January 21, 2014 Fuel system would be the first thing i would look at. Gas rotting in the tank, filter & carb will most definitely be a portion of the issue if not all. Replace the filter & drain the tank of all old fuel, assuming you mixed old and new fuel. Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted January 21, 2014 Fuel system would be the first thing i would look at. Gas rotting in the tank, filter & carb will most definitely be a portion of the issue if not all. Replace the filter & drain the tank of all old fuel, assuming you mixed old and new fuel. +1 on this post, this is something that has to be done on car that has been sitting for years regardless of anything else. Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted January 21, 2014 (edited) Step 1: Check the fuel filter.Step 2: Blow out the fuel lines. Step 3: Check the carb. Maybe find someone with a spare carb you can swap and test it out. Step 4: Fuel pump. It's all about process of elimination and verifying things are okay before you start spending money. A buddy of mine restored his 69 and had a stalling issue. He chased his tail and threw money into replacing parts only to discover it was a clogged fuel filter. Once you can verify the fuel components are okay, move on to the electrical components. Step 1: Check the spark plugs to make sure they aren't fowled and the gaps is set properly. Step 2: Double check the plug wires are hooked up correctly. Step 3: Check the dizzy, inspect cap, points, and rotor. Step 4: Check ignition coil. Step 5: Check the ignition switch. If that's okay, move on to the vacuum. Keep in mind I'm not mechanic, and others may have better advice, but this is just what I've learned over the years after making mistakes of needlessly hemorrhaging money. Don't mean to highjack this thread just a curious question for Big Secz. Big Secz, I understand from other posts that you installed the Borgeson power steering conversion on your car and were having problems with steering return to center. Did you ever resolve this problem? Just wondering because I am interested in doing this upgrade to mine. Thanks Dave Edited January 21, 2014 by det0326 Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 21, 2014 I think there may be something wrong with the carb. How do I go about draining all of the fuel? I can't really do that in my driveway/garage. What do you recommend? Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 21, 2014 I have a full tank of gas... Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted January 21, 2014 (edited) I think there may be something wrong with the carb. How do I go about draining all of the fuel? I can't really do that in my driveway/garage. What do you recommend? U don't have to drain the fuel tank to remove the carb I assume you know this but some people don't. If u already filled the tank full of gas my suggestion would be to do all the other fuel maintenance as cleaning the carb and changing the filters and try to get it running good and maybe you won't have to drain the tank simply run it until you run most of the fuel out. If you won't to drain it though if you don't have an external pump to pump it out you could siphon it out but as I said earlier if you do all other maintenance you might get by without draining tank. Good luck with your problem and I hope you get it fixed. Also should mention that if it started running worse after changing the spark plugs and you think you may have crossed some it would be a good idea to check your wires with the firing order that is usually on the intake manifold. Edited January 21, 2014 by det0326 Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 21, 2014 Hopefully I can just swap out the filters and clean the carb. I reallllly don't want to drain out all the gas. It was my novice mistake when I filled the tank. Really shouldn't have done that. Quote Share this post Link to post Share on other sites
Big Secz 26 Report post Posted January 22, 2014 Don't mean to highjack this thread just a curious question for Big Secz. Big Secz, I understand from other posts that you installed the Borgeson power steering conversion on your car and were having problems with steering return to center. Did you ever resolve this problem? Just wondering because I am interested in doing this upgrade to mine. Thanks Dave PM Sent Quote Share this post Link to post Share on other sites
Arvidsson 22 Report post Posted January 22, 2014 ....so and it keeps stalling when I'm at a stop. I had this issue too. My problem was that the carb flooded the engine with gas. The floats, needle and seat were bad. I boought a carb rebuild kit and it got a hell lot of better. Try adjusting the floats. Don´t know what type of carb you got but on the Holley it´s easy and takes a few minutes. Holley has a great instruction on their website!! Cheers!! Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 22, 2014 I thought it came with a Holley, but it is actually an Autolite 2 barrel carb. I am trying to find a rebuild kit online somewhere. I got it running really smooth yesterday by adjusting the idle, and then I went to turn the car off and it was still running after removing the keys so I had to stall her out by turning the idle wayyyyy down. I also noticed that the brand new spark plugs seemed to have a little oil on them. Any idea on what that could be? I am going to first either rebuild carb or get a new 4 barrel carb. Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 22, 2014 Anyone know how easy/hard it is to rebuild a carb? Quote Share this post Link to post Share on other sites
Arvidsson 22 Report post Posted January 22, 2014 Rebuilding the Holley was easy... and fun! Made a huge difference for me any how :thumbup: Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted January 22, 2014 I thought it came with a Holley, but it is actually an Autolite 2 barrel carb. I am trying to find a rebuild kit online somewhere. I got it running really smooth yesterday by adjusting the idle, and then I went to turn the car off and it was still running after removing the keys so I had to stall her out by turning the idle wayyyyy down. I also noticed that the brand new spark plugs seemed to have a little oil on them. Any idea on what that could be? I am going to first either rebuild carb or get a new 4 barrel carb. When you say still running after you turn the key off do you mean running normally or dieseling? Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 22, 2014 What does dieseling mean? Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted January 22, 2014 (edited) What does dieseling mean?[/quote You rarely see cars do this these days but back in the 70's when car manufactures started adding smog devices on and lowering the compression ratio the combustion chambers tend to build up excess carbon and it would get red hot while running and when you cut the ignition off the red hot carbon deposits would try to keep the engine running. Sort of like a diesel engine but not exactly and I guess this is where the term got its name. When an engine did this it would soung like it was hitting on maybe 2 or 3 cylinders. Edited January 22, 2014 by det0326 Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 22, 2014 How can I be sure? Quote Share this post Link to post Share on other sites
det0326 179 Report post Posted January 22, 2014 How can I be sure? When you turn the ignition switch off you say the engine keeps running normally just like it did with the ignition switch on. If so how do you keep it from running the battery down over night. Because if it continues to run normally after the ignition is turned off then that would mean that the ignition circuit still has power. Quote Share this post Link to post Share on other sites
Arvidsson 22 Report post Posted January 23, 2014 (edited) I would try to find a replacement carb if you are unsure! If it works fine with an other carb you know what the problem is. Maybe you could record a short video and post so all the great guys on this forum can see and hear how the engine keep running. An dieseling engine is very distinct. :smile: Edited January 23, 2014 by Arvidsson Quote Share this post Link to post Share on other sites
Pizzeck 10 Report post Posted January 23, 2014 colbysunday: what you are describing doesn't sound like "dieseling." Dieseling usually does not last long enough to require an adjustment to the carb to make it stop. The old trick I learned to avoid dieseling (assuming the car is an automatic) is to always turn off the ignition while the car is still in drive (rather than park or neutral). This has something to do with how wide the throttle plate is open in park/neutral vs drive. I've never known an engine to diesel when a motor is shut off this way. It was such a common problem in the seventies with my carbureted Chevys that I am still in the habit of turning off my Mustang while it is in drive. Quote Share this post Link to post Share on other sites
colbysunday 10 Report post Posted January 23, 2014 When you turn the ignition switch off you say the engine keeps running normally just like it did with the ignition switch on. If so how do you keep it from running the battery down over night. Because if it continues to run normally after the ignition is turned off then that would mean that the ignition circuit still has power. I turn the idle wayyyy down and stall it out manually. Quote Share this post Link to post Share on other sites
