1965 with 240..... how big of a problem do I have?

[ffjoey]

Ok guys be gentle. I bought a '65 with the original 240 about 3 weeks ago. I was told the motor was rebuilt then sat for years. It was ran by the guy I purchased it from for about 500 miles. The motor does have the appearance of an older rebuild. It was painted but the paint looks older and what you can see of the gaskets they look pretty fresh. So here is the problem, when I bought it the carb was leaking and it ran ok but idled a bit rough. I noticed a little valve tap but nothing too concerning. I chalked the rough idle up to the carb. I purchased the truck and rebuilt the carb. It still runs a little rough at idle but rund great under acceleration. I did notice when I let off the gas it pops out the muffler, not backfire, but a pop pop pop. As I have driven the truck I have noticed it seems to get worse as the motor heats up but still runs nice under acceleration. I only notice the miss at idle or when cruising with a tad of throttle. The valve tap gets louder when the motor is warm as well. I originally thought it had to be a collapsed lifter but a mechanic I spoke to said it is more likely the camshaft. Any thought on this would be very appreciated. Also, do you think I am doing more damage by driving like this for a few more weeks until I have the time and money to get it fixed?

[JojoDVM]

In my experience, the popping from the exhaust is an exhaust leak

[ffjoey]

Jojo, I hope you are right about that. I went out and listened to it again and maybe just maybe the tapping noise is actually coming from the exhaust manifold. I can hear the tapping or ticking sound best when I put my ear towards the back of the engine on the manifold side. It sounds like it is coming from the base of the valve cover right around where the manifolds are. I am correct in thinking the sound of an exhaust leak would worsen as the engine heats up right? It doesn't explain the miss but that could still be the carb. I just did a rebuild kit and tuned it by ear so it may not be working the best. I really hope that is what it turns out to be. Thanks

[JojoDVM]

Depending on where the leak is, yeah I'd say heat could make it worse since it could cause expansion and/or warpage to be exacerbated and say a bad gasket to not fully seal...of course I once had a rust hole in a down tube...no amount of heat or cold could change it...in that case a hole was a hole...lol

[William-in-St George]

Get a piece of garden hose couple feet long. Place it near the noise and listen at the other end. This trick will clearly id an exhaust leak verses more serious noise.

[ffjoey]

Thanks William, I will try that. Just an update. In drving it yesterday the miss is worse then ever. it only does it at idle and when just maintaining speed with a little gas. At quarter throttle or more it seems to run fine. Also, it is noticably worse when the engine is at operating temp. Not so bad when it is first started up. I did tighten the exhaust at the flange and that did quiet the noist a little but it's really running like crap.

[Hunter's 64]

http://classicinlines.com/troubleshooting.asp

Check this site they have a trouble shooting guide ?

Danny

[ffjoey]

Thank you Hunter's 64

[64shortbed]

My '64 (262 I6) would miss when idling and didn't run clean when I first brought it home from Grandpa's house. I rebuilt the carb & tuned it up, but to no avail. I wa standing with the hood open one day and threw a wrench on the intake mainfold bolts and what-do-ya-know, they were loose. I bought an intake and exhaust manifold gasket and torqued the bolts to spec, ran it, and retorqued them. I then bent all those tabs securely over the bolt heads to keep them from backing out. It has run smooth as a sewing machine ever since. I hope your problem turns out to be that easy.

[ffjoey]

I hope it turns out that easy as well. I want to vacuum test it. I assume I take the vacuum line off the carb, plug the line, then hook the vacuum gauge to the port in the carb. Is this correct?

[ffjoey]

I let it run to operating temp today and then sprayed the intake and exhaust manifolds down with WD40. The idle speed picked up and the miss smoothed out for about 30 seconds. I assume that a manifold leak may be the problem after all.

[unibody madness]

Sounds like a leaky intake to me as well. If it sat too long the idle circuit may need some cleaning. Try some sta bil to your fuel and see if it settles down after you manage your manifold leaks.
john

[ffjoey]

Thanks uinbody. Thanks to all you guys. You have all been a big help and I appreciate it. I will let you guys know when I get this figured out.

[64shortbed]

Good news! Hope that solves the problem!

[ffjoey]

Well guys, the intake had the ears cracked completely loose on the front 3 cylinders. The bolts were holding everything together but not holding the intake to the gasket at all. Got another intake and new gaskets and got it all back together. Started it up and it was runnning perfect in the driveway. I let it idle for about 5 minutes and everything sounded great. Got in it for a test run and got about a quarter mile and it suddenly died. Turned the key and just got the solenoid buzzing. Opened the hood and everything looked ok. Turned the key again and it started right up. Started to turn it around and it died again. Couldn't get it to do anything except buzz the solenoid. It has 12.77 volts at the battery standing and 11.8 volts when I turn the key. I ended up having to push it home. All i can think is the voltage regulator maybe, any ideas?

[65TremecGT]

Maybe a bad ground somewhere? Sounds like a new problem maybe caused by working around the engine? Good Luck!

[ffjoey]

65Tremec you were right. The wires leading to the voltage regulator have rubbbed on the core support leaving them exposed against it in a very small spot. Moved them away from the support and it started right up. Thanks

[ffjoey]

Well guys, I thought I had this licked but something is still really wrong. The electrical problem is solved but my initial problem is now worse. I start it up and it starts up perfect. I no longer even need to pump the gas. I just turn the key and it fires right up. Runs great while below full operating temp but when it gets warmed up it starts missing then dies. It starts back up, runs for a few seconds then dies again. It seems like it's not getting fuel but that doesn't make sense because it runs great until the engine is hot. What in the world am I missing here?