It just never ends! (sorry, kinda long)

[BiggSixx1970]

I love my Chevy, its a 43 year old daily driver I picked up last year, for the most part it's been a damn good running truck for the year I have owned her. being all original but it seems when it rains, it pours. When it has a problem, they come in pairs!(or more)

Now the novice sunday shade tree mechanic in me is stumped.

It received a tune up last spring: Fuel pump, new distributor, plugs, plug wires, fuel filter, air filter, carb rebuild, coil, battery, oil change to high mileage blend, fuel pump.

It has ran like a top every since then, It received another tune up this spring as well: spark plugs, new heater hoses, new upper and lower radiator hoses, full cooling system flush, new thermostat, new air filter, new fuel filter, this was all TWO WEEKS AGO

So my dad makes the comment to me, "hopefully your water pump doesn't go out, Chevy's like to do that when you flush their radiators from my experiences"

Well, the old man totally jinxed me and it appears I'm getting a little weep action from the water pump now, noticed as of the other day (no biggie, water pump is no big deal to replace)

The problem now is for whatever reason, my engine keeps shutting off unless i give it gas, accelerating or slowing down in gear(its a manual). When I push in the clutch, if i'm not giving it gas, the idle drops really slow, then it dies.. Thoughts?

Thanks for the help! You guys are awesome

[tommys72]

My cavalier did the same thing, flushed the system and bam...water pump goes bad...the fuel thing sounds to me like the filter is clogged maybe, or carb needs cleaned. Giving it gas makes enough pressure to get past the clog but not at idle
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[GASoline71]

Start with the EZPZ stuff. Fuel filter...

Gary

[BiggSixx1970]

I just put a new one on a couple weeks ago though, its cheap and easy to replace but I did just put a new one on

[VetteVet]

Here's a few things that will cause that.
1. Carb idle screw.
2. Carb mixture screw
3 distributor retarded too much.
4. vacuum line off the advance or the carb.

[BiggSixx1970]

Originally Posted by VetteVet

Here's a few things that will cause that.
1. Carb idle screw.
2. Carb mixture screw
3 distributor retarded too much.
4. vacuum line off the advance or the carb.

Ah the vacuum advance! I didn't think about that, It got a new distributor last summer, with a new advance, buut the line into the carb is a little sketchy

The weather here has been verrrry wet, cool, and very humid. I know that can play havoc on carbs. But I don't see why my distributor would go out of time, doesn't that normally take something catastrophic?

Messing with the fuel/air mix on the carb is something I know NOTHING about, I was always told if it's working fine (which it has been until now) not to go muckin' around with your carb. It is a Rochester Mono-jet so there's only two screws on it, but I haven't touched those cause I don't wanna goof anything up. After I gave it a good tune up last spring/summer my buddy's dad who's worked on his share of these things got under the hood with a screwdriver and 'tuned' my carb for me and it has ran great since, I don't know why the screws would back off or sink in further messing with the mixture, but hey i've seen weirder things happen!

Appreciate the replies!

[VetteVet]

Originally Posted by BiggSixx1970

Ah the vacuum advance! I didn't think about that, It got a new distributor last summer, with a new advance, buut the line into the carb is a little sketchy

The weather here has been verrrry wet, cool, and very humid. I know that can play havoc on carbs. But I don't see why my distributor would go out of time, doesn't that normally take something catastrophic?

Messing with the fuel/air mix on the carb is something I know NOTHING about, I was always told if it's working fine (which it has been until now) not to go muckin' around with your carb. It is a Rochester Mono-jet so there's only two screws on it, but I haven't touched those cause I don't wanna goof anything up. After I gave it a good tune up last spring/summer my buddy's dad who's worked on his share of these things got under the hood with a screwdriver and 'tuned' my carb for me and it has ran great since, I don't know why the screws would back off or sink in further messing with the mixture, but hey i've seen weirder things happen!

Appreciate the replies!

those distributors have a hold down bolt to keep them from turning but if they're not tight enough the distributor will turn. I thought you might have bumped the vacuum advance diaphragm while changing the water pump and moved it.
The mixture screws are best adjusted with a vacuum gauge for highest vacuum at idle but it's easy if you have the gauge/ You just turn them in or out until you get the best vacuum and then set the idle screw so the engine idles at the proper RPM. They don't usually move on there own so that may not be the problem.

[BruthaMan]

I can sympathize with you, for sure. Some days I wonder if things like this happen to others, or if it's just me. When it rains, it pours...welcome to Noah's Ark!

As others have suggested, check all of your vacuum lines. Check PVC valve (driver's side valve cover on mine, but is GM crate motor) to carburetor.

One morning this past winter, after another sleepless night, I headed out to get some donuts. Truck was running abnormally rough, even for being cold. Shortly after I departed, I pulled over into a Walmart parking lot. Got the flashlight out and sure enough, a vacuum line had come off.

Was running very rough, barely staying started. After plugging the vacuum line back in, everything smoothed out.

Same happened with the PVC valve once. Had popped out of the valve cover and running rough.

Hope that helps. Don't let it get you down. Just remember, it happens to "bruthaman" too!

[domeier]

Clogged idle jet will do that. What carb do you have?

[BiggSixx1970]

Originally Posted by domeier

Clogged idle jet will do that. What carb do you have?

Rochester Mono-Jet

[PanelDeland]

One more question.Did you change the filter in the carb or does it have an inline?The one in the carb will be behind the 1' fitting the fuel line screws into.It could still be in there even with an inline and may be clogged.

[BiggSixx1970]

Originally Posted by PanelDeland

One more question.Did you change the filter in the carb or does it have an inline?The one in the carb will be behind the 1' fitting the fuel line screws into.It could still be in there even with an inline and may be clogged.

There is no longer a filter in the carb, I took it out when I stripped out the fuel inlet to the carb (oops!).. So I sealed it shut last summer with some JBWeld and installed a plastic inline before the fuel pump

[domeier]

"...When I push in the clutch, if i'm not giving it gas, the idle drops really slow, then it dies..."

That's really weird. Maybe the clutch linkage is interfering with the throttle linkage?

[BiggSixx1970]

Originally Posted by domeier

"...When I push in the clutch, if i'm not giving it gas, the idle drops really slow, then it dies..."

That's really weird. Maybe the clutch linkage is interfering with the throttle linkage?

No sir, there is a large gap in between the two sets of linkage

[CC69Rat]

Vacuum leak somewhere - VA on the dist, or maybe to the brake booster.

My 70 was doing this exact thing last weekend after I swapped the brakes out. As it turns out we just forgot to connect the vacuum line to the brake booster. As soon as it was connected back up, it was fine.

Does it smell like it's running really rich if you just let is sit, idle , and die .. ?

[BiggSixx1970]

Originally Posted by CC69Rat

Vacuum leak somewhere - VA on the dist, or maybe to the brake booster.

My 70 was doing this exact thing last weekend after I swapped the brakes out. As it turns out we just forgot to connect the vacuum line to the brake booster. As soon as it was connected back up, it was fine.

Does it smell like it's running really rich if you just let is sit, idle , and die .. ?

There are no power brakes, so no booster. I will check my vacuum advance, and make sure its sealed up.. But If the vacuum advance is disconnected, it should still idle correctly, because you have to remove the vacuum advance when you go to set timing. (which I did last summer when i replaced the distributor) You time the engine without the vacuum advance connected if i remember right

[BiggSixx1970]

Still haven't figured out my fuel gremlin yet.. Replaced my fuel filter again, no positive result. I foresee a carb rebuild? maybe somethings gummed up there, or in a fuel line.

[yukon]

You might check your distributor cap, since you said it has been humid there. Condensation and corrosion are a common problem on cheap caps.
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