Popping through carb

[MacGyver]

My car sat for about a year and a half without being drivin. I've recently found the time and space to bring the ol' beast back to life. I got it running and it would backfire through both the exhaust and carb. I've rebuilt the carb and given it a new set of points, condenser, plugs, etc. The backfiring through the exhaust is no longer an issue but it still pops through the carb. Under load the pop will get really loud, almost like a backfire. This happens no matter where the timing is set.

Any ideas would be appreciated.

Thanks

Mark

[greg g]

Might be an intake valve hanging open a bit. Do a compression check if you have a cylinder with a substantially lower reading than the others that would indicate the problem, a Vacuum gauge would also show a jerk of the needle for showing a bit lower reading as that cylinder comes to bear. It might clear itself up with a few heatcycles, might not. If it doesn't clear up you might burn it if you run it that way for and extended time.

[MacGyver]

Thanks for the insight. I'll check the compression in the morning and see if I can dig up my old vacuum gauge as well.

[MacGyver]

So I checked the compression and it looks like you're on to something...

#1 110psi

#2 5psi

#3 10psi

#4 85psi

#5 95psi

#6 115psi

I guess the next step is to do a valve job...?

[martybose]

I'd say the first thing is to pull the head and see if the head gasket is blown between #2 and #3...................

Marty

[MacGyver]

Thanks Marty,

I'll get on that this weekend and let you know what I find.

Mark

[MacGyver]

Hey, just a quick note here to say thanks. As you suspected I had a blown head gasket between #2 & 3. I went to see the 'boys in blue' over at my local NAPA store and they first told me "we don't have it [re: the head gasket] and it'll take about a month to get one." "Oh wait, I'm not showing any gaskets in the country, we can't get one at all." I gave him the part # from our trusty forum here and he said "we don't use that number anymore but, we can't get one anyway." I drove 2.5miles to the Bumper to Bumper and he said, "I'll have it tomorrow morning." SOLD! For what its worth...

Thanks for your insight. Its been a while since I've done any "serious" wrenching on anything other than a motorcycle but after an hour soak in the good ol'

"PB Blaster" I got all the head bolts out without a problem.

Mark

[captden29]

mark, i am doing the head gasket on my 54 windsor . i have the head off and am cleaning everything up. it is an easy job, just time consuming cleaning and spray painting some of the parts. i will take the head to a machine shop to have it checked for straightness and possible milling if necessary. i already have 2 head gaskets and i use gasket paper to make any others. and yes, the head gaskets are readily available so i don't know what the NAPA problem was. the NAPA near me is much better, i just got a fuel pump and oil filter from them. i had 2 adjacent cylinders low and even though the car ran well it would not idle well. i also had a fuel percolation problem so i am movig the fuel line away from the exhaust manifold. also rebuilding the carb, so the car should be well improved. the people on this forum will help you any way they can. also, use the search site for more info. dennis

[Tim Frank]

NAPA is pretty inconsistent I guess; it seems to depend on the individual stores and of course the "liveware" installed at the store. Anyone know if they are franchises or corporately owned?

We have several outlets in this town, and they are different as chalk and cheese.

When I was sourcing all the brake parts for my wife's D-25C, store #1 (and counter guy #1) said they couldn't help with anything that old...didn't have even parts listings and the numbers that I pulled off the website made no sense to him. (blamed it partly on US numbers vs Canadian)

Store #2, counter guy #2 took it as a challenge, asked me for one of the part numbers from the website, called me back within 15 minutes later and said it was the master cylinder, "they could have it tomorrow...is that OK? and what are the rest of the part numbers?"

Bottom line, ALL the parts that I was after except return springs were delivered overnight and I picked them up next day.

[Young Ed]

The ones by me are usually pretty good. Depends on the counter guy. I was trying to buy a 6v flasher for my turn signal project a few weeks ago. He knows me and my old stuff I'm usually looking for so he went right to the books. Couldn't find it anywhere. So just for fun I said try looking one up for a 52 plymouth. Right in the computer and it was there the next day. Getting a second one proved to be a little bit of a challenge but they came through eventually.

[MacGyver]

She's back on the road and running smoothly. Thanks.