Daveman

Hello All,

I'm brand new to the site and have a puzzling question on my 63 98 convertible engine. I left the car for three weeks with a welder to have some framework done and when I picked the car up it was running like garbage.
First thing I noticed was the way the car "chugged" along like it was running a cylinder shy, giving the welder the benefit of the doubt, I thought it's been a while since a tune up and maybe it was time. I did the tune up, points, cap, rotor, wires, plugs, set everything to spec and it's still chugging as though it has a miss and occasionally at low speed on a hill I can get it to give me a little backfire up through the intake. Once I'm above 40 all seems ok, below 40 the car actually vibrates under any load and has a noticeable reduction in power. The idle is a little rougher but nothing crazy. I checked the vacuum advance by sucking on the hose and I found no leaks but I also couldn't move it with my lungs, when I connect it back to the engine there is a noticeable idle increase so I'm assuming it's working ok.
Any ideas as to what might be causing this?
I haven't done a compression test yet and hope that It's not from someone joy riding the car way past it's limits and bending/blowing a valve.
Any thoughts would be appreciated!

Dave

Oldskeeper

Hello Dave and welcome to the best info site around.
You state that you had the frame welded,did this change where the cross mount is located,this could change the length of the TV shifter rod changing when the shift happens or shift points.
Steve

Daveman

No, the welding was to outer frame sections under the doors.

rocketraider

That's the exact reason I write down the mileage any time I leave my car with anyone for work. More than a couple miles for road testing, somebody better have an explanation.

Make sure a fuel line didn't get crimped or flattened.

Oldsguy

Hopefully a compression test won't reveal any valve damage although that would mean you are still looking for a cause of your problem. Welcome to CO and keep us updated on your findings.

Olds64

Never heard of that before, but whatever works.

Definitely check your TV adjustment. The older cars with Slim Jim transmissions were notorious for having misadjusted throttle valve linkages.

Daveman

Thank you all for your help, I'm going to add drygas in case it's water and check the compression to see if it's abuse!

Daveman

Bluevista

I've heard of weird things happening if the battery isn't disconnected before welding. Or did they gas weld? Also heard of the welder ground attached to something where it has to search through to complete the circuit and fries things out. Some guys don't disconnect a thing and have no problems? May be more of a problem with computers and stuff. Did you check the fuel line and make sure they didn't crush or crimp it working around the frame rails? Junk in the fuel filter dislodged from the line?
It could have nothing to do with anything the place did, those gremlins do pop up, but why always after some other guy touches the car? If I let anybody else drive any car of mine they always manage to break something or it runs weird afterwards, I swear the cars know.
Sounds like your heading down the right path with the process of elimination, hope it's something small and external.

Daveman

I think you might be on to something bluevista. The fuel line would have been disturbed and it was in pretty crusty shape. The day before I dropped the car off I replace the fuel pump except I didn't have a filter in the glass bowl, I have an in line filter (see thru plastic) just before the carb. I'll look down this avenue and let you know what I find, thanks again!

Daveman