engine and drivetrain 1600 popping from the carb?

[Kauboi]

Hey guys, I bought a '69 1600-2 a couple of weeks ago and have been driving it since. I've got a one way hour commute to work and she's held up great thus far. A few days ago I noticed an occasional backfire when letting off the gas and a slight stutter when accelerating up hill. I didn't think much of it at first but on my way into work yesterday she crapped out at a stoplight. I popped the hood and notice one of the nuts that holds the carb on had wiggled it's way an inch up the bolt! I didn't even have a screwdriver on me so I managed to get it started and picked up some new plugs and rotor button (they didn't have wires or dist cap) and went into work. Tightened up the bolts on the carb and pulled the old plugs... they look terrible. Lots of corrosion and one was almost bridged! Got a lot of oil leaks here and there so they also had a little residue on them. So I gapped and installed the new plugs (after spraying everything down with WD-40 to clean the oil off) and rotor button, pulled and cleaned the fuel filter and even washed my hands in preparation to drive home.

Started her up and it almost sounds worse than before... idling very very rough. Won't even stay running unless I give it gas, and even with the pedal on the floor it has very little power and takes a minute to rev up. Still backfiring and once I let off the gas it lets out a POP from the carb. Eventually the engine craps out with a breathy "PFFFT!" and dies...

Been researching the popping carb and it seems it could be anything from a timing problem to valves; etc.

Any advice on where to start diagnosing or stories on similar problems are GREATLY appreciated!

[carlkkreienkamp]

sounds like one or more plug wires were mis-connected. reexamine 1-3-4-2 firing order from distributor.

[Mike87]

Check the timing.

[72koop]

Identify the carb.

Popping from the carb is indicating a lean condition- plugged jets, not enough fuel, incorrect fuel level. A loose screw can let more air into the mixture depending on what screw(s)- Tighten them all up and check the carb to manifold nuts to be sure they're tight. ( Not too tight.) But first clean the carb bowl and the jets.

Condition of the old plugs- oiled or carbon?

Hesitation- usually the accelerator pump or clogged brass jet. Look down the carb and operate the throttle fast- there should be a squirt of gas that gives the engine a rich mixture when you press on the gas. No squirt- hesitation. Again- what carb type?

It sounds like the car was run infrequently for some time or sat, built up carbon, was running rich for some time. Then you started driving it and things are starting to loosen up built up junk. Today's gas has alcohol which has water; both contribute to clean engines to varying degrees.

Once you get it running mostly normal, go and blow it out- italian tuneups- hard downshifts.

[jscaptura1]

Put in a NEW fuel filter, I know you cleaned the old one, but if the car had not run much before you bought it the junk in the gas tank will be stirred up & may foul the filter again. Also check your vacuum lines & try to find a new D-Cap. I had an awful time getting mine to stop stalling, turned out the D-cap was cracked & eventually fell off as I was setting the timing. Also check your fuel pump. If it is not creating enough suction it will starve the carb & engine.

Good Luck

[jscaptura1]

Put in a NEW fuel filter, I know you cleaned the old one, but if the car had not run much before you bought it the junk in the gas tank will be stirred up & may foul the filter again. Also check your vacuum lines & try to find a new D-Cap. I had an awful time getting mine to stop stalling, turned out the D-cap was cracked & eventually fell off as I was setting the timing. Also check your fuel pump. If it is not creating enough suction it will starve the carb & engine.

Good Luck

[Kile Brekke]

I had a similar popping noise almost a backfire with a hiss coming out of my carb recently. I replaced plugs, wires, rotor and cap. Problem got worse.

However I neglected the badly worn points (they were not available at a local autostore at my location) I ended up ordering them and replaced with proper gap (.016") and my symptoms were solved.

[Kauboi]

thanks for all the advice you guys, this will be my project for the weekend. just figured i'd get a head start on deciding where to look first. i'll definitely try to find the cap and points first thing, before i get ahead of myself with the timing & valves. it just crapped out all of a sudden and had me pretty spooked, being my only means of transportation.

will keep you posted and will try to post pics of the old plugs to see what you think.

thanks again

[schwartzerritter]

email me if you have serious Questions I am in Holland time difference . but I have been driving these cars since 1975.

[c.d.iesel]

remove the cam cover

check the valve clearances

COMPRESSION TEST - if the compression

is low - if you have less than 120 psi in one or more cylinders

nothing else you do will make any diff.

idle jets plugged

your mechanical fuel pump diaphram is near dead

float bowl is not filling

points clossed up - or burnt

yea timing after points are touched

burned carb mounting gasket - you said the carb was loose?

tightening it may not cure the burnt gasket gap

popping on De-Cell ? got exhaust system leaks?

[bracohen]

Oh hey I saw that car on Craigslist recently. I also saw it a few months ago for about 4-5 times what they were asking for this time around. I'm not sure if it changed hands between that time, but hopefully it's something simple that you can work out!

[Kauboi]

so, upon closer look on saturday the distributor had a loose bolt so my timing was all kinda funked up. fixed that and put in some new points and she's running good. a little smokier than i remembered so i'm taking it in for a compression test, valve adjustment and proper timing, as i don't have a timing light. thanks for all the helpful advice, hopefully won't have to dig too much deeper into the valve situation than some rings...