Fiddy B2C Posted June 26, 2018 Report Share Posted June 26, 2018 Ok all you mechanics out there, I need some help with ole Fiddy. But as usual, some background. I had surgery on my shoulder about 6 weeks ago. (Torn rotator cuff, bicep tendon and another tendon that holds the arm in the socket). Anyway, I haven’t been able to use my right arm for around 4 weeks, meaning I haven been able to handle the gear shifter or turn the wheel of ole Fiddy, so she has sat idle for a while. I took her out on Friday, and drove her about 10 miles or so, in the 90+ degree Florida sun. She did well. Then, I got antsy on Sunday and loaded up my dog and we went for a ride, again in the 90+ degree Florida sun. I stopped for some gas, filled her up, and got back in to leave, but she wouldn’t start. Opened the hood and saw there may have been some vapor lock going on so I let her sit for a while. I tried her again in about 10 minutes and she started, however she runs like she’s on 4 cylinders. She won’t idle, but runs OK but rough when gas is applied. I eased her home by keeping my foot on the gas at stop lights. She’s home now, and I figured it sounded like an ignition problem. I checked the cap and rotor, they were a little pitted, so I changed them. The points were changed back in Sept. of last year so I didn’t mess with them. She’s still not idling and is running really rough with some backfiring on deceleration or down-shifting. I’m thinking maybe bad gas? But not sure if the effects of bad gas would be that immediate. Any help/recommendations from you guys on what to check next would be greatly appreciated. Thanks! Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted June 26, 2018 Report Share Posted June 26, 2018 Have you pulled the spark plugs for inspection? Quote Link to comment Share on other sites More sharing options...
DJ194950 Posted June 26, 2018 Report Share Posted June 26, 2018 12 minutes ago, Fiddy B2C said: I checked the cap and rotor, they were a little pitted, so I changed them Did you change the condenser? Spark color at plugs end of wires? Coil may be going out with heat losing spark intensity, or getting weak the the heat makes worse? Just a couple of possibilities. DJ Quote Link to comment Share on other sites More sharing options...
Fiddy B2C Posted June 27, 2018 Author Report Share Posted June 27, 2018 (edited) 5 hours ago, Don Coatney said: Have you pulled the spark plugs for inspection? 4 hours ago, DJ194950 said: Did you change the condenser? Spark color at plugs end of wires? Coil may be going out with heat losing spark intensity, or getting weak the the heat makes worse? Just a couple of possibilities. DJ Thanks guys. Sorry, I should have mentioned that I checked the plugs, they look good, a light brown color, no gas or oil. I swapped out the coil earlier today, still no go. I have a buddy who thinks it may be a clogged idle jet in a carb? But I’d hate to have to pull the carbs off and mess with them. I rebuilt them last year and they have been running great, but there could be some crud in there I guess. I haven’t checked the condenser, I’ll look into that, or just swap it out. Any other suggestions on where to look? Edited June 27, 2018 by Fiddy B2C Quote Link to comment Share on other sites More sharing options...
JBNeal Posted June 27, 2018 Report Share Posted June 27, 2018 Marvel Mystery Oil in the gas may improve your results Quote Link to comment Share on other sites More sharing options...
greg g Posted June 27, 2018 Report Share Posted June 27, 2018 Could be a (sorry to bring this up) a head gasket failure. D a compression check. Likely a dry failure between 5 and 6, the miss and rough dle resulting from swapping compression through the failure area. Quote Link to comment Share on other sites More sharing options...
JBNeal Posted June 27, 2018 Report Share Posted June 27, 2018 I reckon to verify, pull the plug wires on #5 and #6 to see if that changes the engine performance... Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted June 27, 2018 Report Share Posted June 27, 2018 Go back to the points and recheck them Verify condition and gap and if it has the separate tension spring, it's still in place. You can check cylinder misfires by using your timing light on the coil to distributor wire, looking for a steady flash or use it to pinpoint a misfiring plug by attaching the lead to individual cylinders and watching the flashes. Use it as a diagnostic tool. If you get erratic flash patterns on all cylinders, you have some ignition work to do, pne or two cylinders, probably plugs, regardless of how they look or plug wires, steady patterns on all, probably fuel or mechanical. 1 1 Quote Link to comment Share on other sites More sharing options...
PT81Jan Posted June 27, 2018 Report Share Posted June 27, 2018 (edited) Maybe nothing complicated ... I exactly had the same symptoms two times after a filling up my truck at the gas station. That the engine did not want to start then was caused by a pretty warm engine at a pretty warm summer day. But this finally had nothing to do with the main issue. Probably by filling in the gas some dirt particles stirred up a found their way pretty quick from the tank to the carburetor. Clogged the idle jet just enough to cause the issue that you described. Opened the cover of the carburetor, applied compressed air to the jets and 20 minutes later the engine purred again as it should. Btw, I do not have an extra filter to the fuel line, just the two glass bowls at the pump and just before the carburetor. If there is a bit dirt on the bowls ground, the chance is high that dirt in the jet is the cause. Just a thought and easy to check. Edited June 28, 2018 by PT81Jan Quote Link to comment Share on other sites More sharing options...
48Dodger Posted June 29, 2018 Report Share Posted June 29, 2018 Heat has a way of "breaking" things free too. Crud in an original gas tank can lay dormant for years before a rebuild...get "softened" by fresh gas, and start to break free on a hot run. Did you replace the gas tank? Have it hot tanked?.....* One deal that can fool some people, is the pick up tube in the gas tank. Its bent at a 90 degree angle to the floor of the tank at its last few inches. I have found decay and pin holes that would be above a 1/8 full, maybe 1/4 full tank. This of course would aid in fuel starvation. There is no filter on the end either, so chunks of scale and debris can get stuck as well. 48D * don't put a chain in an original gas tank to help clean it....might crush the pick up tube. 1 Quote Link to comment Share on other sites More sharing options...
Solution Fiddy B2C Posted July 21, 2018 Author Solution Report Share Posted July 21, 2018 I have an update for you all. After trying all the “normal” stuff that you guys recommended, the winner is...drum roll please...Greg g.... everything checked out OK however compression check results revealed cylinders 1-4 between 100 and 105 psi, cylinders 5&6 - 70 psi. So apparently there is a dry head gasket leak between the cylinders. Oil is not emulsified, no exhaust in the radiator. Ok so all that being said, any recommendations on additional work that should be done when changing a head gasket? Any pointers I should know before digging into this? thanks once again for all the help here! Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted July 21, 2018 Report Share Posted July 21, 2018 I would expect to see much less than 70 psi between the two cylinders if the had gasket was blown out between them. That would usually result in less than 20 psi. Engines with 70 psi across the board will still run. I suppose it’s still a possibility. It’s easy enough to pull the head and have a look. Quote Link to comment Share on other sites More sharing options...
JBNeal Posted July 21, 2018 Report Share Posted July 21, 2018 Have ya pulled the valve covers and turned the crankshaft to verify if the valves are travelling properly? Quote Link to comment Share on other sites More sharing options...
kencombs Posted July 21, 2018 Report Share Posted July 21, 2018 Before pulling the head I'd want to verify the leak. Pull both 5 and 6 spark plugs. Install an adapter in either hole to attach an air line. Listen for leaks in the other hole. Or, pick up a real leak down tester and do a real leak down test on all cylinders to see what is going on. Sounds of leakage at carb, exhaust, other cylinders, and oil fill can tell you loads about the condition of valves, rings and gaskets Quote Link to comment Share on other sites More sharing options...
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