76 Difficult Cold Starts

YOur 76 has a Quadrajet or Quadrajunk or whatever you want to call it.
The main metering wells are leaking since the solder plugs that colse
the drilled ports have gotten loose. Take the carburetor off and buy a
rebuild kit that has the foam plug that you can install between the
throttle plate and the bowl. This will cure the hard start problem.
You see, the problem is the gas drips out of the main float bowl until
it is all gone and you end up cranking it for an extended period of time
to fill the bowl back up. Do not get arebuilt carb as you know how
yours works and the rebuilds are trash. It is easier to get a kit for
yours and install the foam block between the bowl and throttle plate.

daveo76 wrote:

> My relatively stock, L48 '76 is getting more difficult to cold start.
> I'm probably up to 10 seconds of total cranking time for most
> overnight cold starts. It starts fine after sitting all day at work
> and it also starts great hot. The choke appears to be working fine.
> I've recently replaced the fuel filter, plugs, wires, cap, rotor, --
> all the normal tune-up parts. While replacing the fuel filter I
> cranked it for a sec. to clear the line and check flow. Fuel was
> pumped out immediately, but do I need to check fuel pressure to rule
> out the pump? Can you rent fuel pressure gages from an auto parts
> store? Any thing else I should check?
>

<<...no problems with accelerating, (although some stumbling when cold)...>>

Realize that every single car with a carburetor is never going to run so
great when cold. A little stumbling when cold can be considered normal.
You should be driving the car very gently until it warms up anyway.

<<...The fuel filter is a basic Fram replacement, I didn't see anything that
looked like a check valve and it looked very similar to the one I pulled
out...>>

The "check-valve" is inside the filter. If you look at the small hole in
the center of the filter and see what looks like a piece of white plastic
blocking the hole, that is the check-valve. If you just see a hole with
nothing covering it, then there is no check-valve. I've seen modern Fram
replacements with and without the check-valve... but I would not worry too
much about it because I have to question how effective that check-valve
really is anyway. Never tested its effectiveness. But GM/Delco originally
put them in there for a reason and they aren't stupid.

<<...Is there any benefit to removing the tiny in-carb filter and using a
regular inline filter instead (between pump and carb)? >>

Some say for extreme high performance the tiny in-carb filter can restrict
fuel flow but I've never had a problem. On some cars though, I did add a
good quality inline filter with a clear (see-though) housing... it's neat to
be able to see the fuel, can help in some troubleshooting situations. But
if you add an inline filter, try not to locate it in an area that will get
excessively hot, otherwise you may increase vapor lock problems.

<<... Regarding HEI module - will an auto parts store that advertises free
diagnostics check this? Is it checked in-car?...>>

They will probably not check for it. You get what you pay for. A module is
cheap enough though that if you suspect it as possibly being faulty, just
replace it. I forget... I think they are about $30 or less.... can't
remember... but I did replace several of them on late `70's GM vehicles. In
some cases the car simply will not start if and when the module goes bad.
You could get stranded. So... if your module is old, it's probably not a
bad idea to just replace it regardless. These things have a life. It's
easy enough to change.

<<...no problems with accelerating, (although some stumbling when cold)...>>

Realize that every single car with a carburetor is never going to run so
great when cold. A little stumbling when cold can be considered normal.
You should be driving the car very gently until it warms up anyway.

<<...The fuel filter is a basic Fram replacement, I didn't see anything that
looked like a check valve and it looked very similar to the one I pulled
out...>>

The "check-valve" is inside the filter. If you look at the small hole in
the center of the filter and see what looks like a piece of white plastic
blocking the hole, that is the check-valve. If you just see a hole with
nothing covering it, then there is no check-valve. I've seen modern Fram
replacements with and without the check-valve... but I would not worry too
much about it because I have to question how effective that check-valve
really is anyway. Never tested its effectiveness. But GM/Delco originally
put them in there for a reason and they aren't stupid.

<<...Is there any benefit to removing the tiny in-carb filter and using a
regular inline filter instead (between pump and carb)? >>

Some say for extreme high performance the tiny in-carb filter can restrict
fuel flow but I've never had a problem. On some cars though, I did add a
good quality inline filter with a clear (see-though) housing... it's neat to
be able to see the fuel, can help in some troubleshooting situations. But
if you add an inline filter, try not to locate it in an area that will get
excessively hot, otherwise you may increase vapor lock problems.

<<... Regarding HEI module - will an auto parts store that advertises free
diagnostics check this? Is it checked in-car?...>>

They will probably not check for it. You get what you pay for. A module is
cheap enough though that if you suspect it as possibly being faulty, just
replace it. I forget... I think they are about $30 or less.... can't
remember... but I did replace several of them on late `70's GM vehicles. In
some cases the car simply will not start if and when the module goes bad.
You could get stranded. So... if your module is old, it's probably not a
bad idea to just replace it regardless. These things have a life. It's
easy enough to change.

<<...and remember the old time ways...blip it as bit as you shut it off...
it fills up the bowls in the carb, and makes the next start easier...>>
-----------------

This doesn't make sense to me. As long as the engine is running, even just
idling, the fuel pump is delivering a pretty large amount of fuel volume and
pressure to the carb. The carb bowl should always be totally full while the
car is idling, so I don't see why one would ever need to blip the throttle
before shutting off the engine. Blipping the throttle will activate the
accelerator pump and will shoot a bit of extra fuel down into the intake
though... but that's not a good thing because after you shut the engine off,
any extra fuel in the intake may make its way down into the cylinders,
washing oil off the cylinder walls and ultimately getting down into the oil.
I would say that blipping the throttle just before shutting the engine might
only be a bad thing, not a good thing. I can't see any good reason for it.
Any extra fuel that you shoot into the intake would disappear by the next
day anyway so it will not help with starting.

<<...and remember the old time ways...blip it as bit as you shut it off...
it fills up the bowls in the carb, and makes the next start easier...>>
-----------------

This doesn't make sense to me. As long as the engine is running, even just
idling, the fuel pump is delivering a pretty large amount of fuel volume and
pressure to the carb. The carb bowl should always be totally full while the
car is idling, so I don't see why one would ever need to blip the throttle
before shutting off the engine. Blipping the throttle will activate the
accelerator pump and will shoot a bit of extra fuel down into the intake
though... but that's not a good thing because after you shut the engine off,
any extra fuel in the intake may make its way down into the cylinders,
washing oil off the cylinder walls and ultimately getting down into the oil.
I would say that blipping the throttle just before shutting the engine might
only be a bad thing, not a good thing. I can't see any good reason for it.
Any extra fuel that you shoot into the intake would disappear by the next
day anyway so it will not help with starting.

<<...The main metering wells are leaking since the solder plugs that close
the drilled ports have gotten loose. Take the carburetor off and buy a
rebuild kit that has the foam plug that you can install between the throttle
plate and the bowl. This will cure the hard start problem...>>
--------------

Those plugs under the bowl may or may not be leaking. The foam piece that
some kits have to prevent the plugs from leaking does not work. It just
absorbs the fuel if anything which does not help the situation. If you
suspect leaking plugs (under the bowl), the best way to fix it is to drill
out the original plugs, tap the holes and installed allen screws with good
sealer.... or install press-in plugs with epoxy. Since this is a bit of a
pain for the average backyard mechanic (and dangerous too because if you
slip with the drill your could destroy the carb), another method that seems
to work well is simply covering the entire existing bowl plug area with good
quality epoxy. Make sure to clean and rough-up the area thoroughly before
applying epoxy. Let the epoxy set for at least a whole day before
reassembling the carb etc. I have epoxied carbs this way and found the
epoxy to still be holding strong years later with zero leakage from the
plugs. In general, you may just want to rebuild your carb and give it a
full "blueprinting". This way you will know your carb is good.

<<...The main metering wells are leaking since the solder plugs that close
the drilled ports have gotten loose. Take the carburetor off and buy a
rebuild kit that has the foam plug that you can install between the throttle
plate and the bowl. This will cure the hard start problem...>>
--------------

Those plugs under the bowl may or may not be leaking. The foam piece that
some kits have to prevent the plugs from leaking does not work. It just
absorbs the fuel if anything which does not help the situation. If you
suspect leaking plugs (under the bowl), the best way to fix it is to drill
out the original plugs, tap the holes and installed allen screws with good
sealer.... or install press-in plugs with epoxy. Since this is a bit of a
pain for the average backyard mechanic (and dangerous too because if you
slip with the drill your could destroy the carb), another method that seems
to work well is simply covering the entire existing bowl plug area with good
quality epoxy. Make sure to clean and rough-up the area thoroughly before
applying epoxy. Let the epoxy set for at least a whole day before
reassembling the carb etc. I have epoxied carbs this way and found the
epoxy to still be holding strong years later with zero leakage from the
plugs. In general, you may just want to rebuild your carb and give it a
full "blueprinting". This way you will know your carb is good.

In >,
(daveo76) writes:
>
==================snip>>>
>Regarding HEI module - will an auto parts store that advertises free
>diagnostics check this? Is it checked in-car?

Twas was behind the counter, removed from the
distributor.

Regards, "Mike"
-- mikeellison3xxxatzzzyahoo.com --

In >,
(daveo76) writes:
>
==================snip>>>
>Regarding HEI module - will an auto parts store that advertises free
>diagnostics check this? Is it checked in-car?

Twas was behind the counter, removed from the
distributor.

Regards, "Mike"
-- mikeellison3xxxatzzzyahoo.com --

"Fred" > wrote in message et>...
> <<...The main metering wells are leaking since the solder plugs that close
> the drilled ports have gotten loose. Take the carburetor off and buy a
> rebuild kit that has the foam plug that you can install between the throttle
> plate and the bowl. This will cure the hard start problem...>>
> --------------
>
> Those plugs under the bowl may or may not be leaking. The foam piece that
> some kits have to prevent the plugs from leaking does not work. It just
> absorbs the fuel if anything which does not help the situation. If you
> suspect leaking plugs (under the bowl), the best way to fix it is to drill
> out the original plugs, tap the holes and installed allen screws with good
> sealer.... or install press-in plugs with epoxy. Since this is a bit of a
> pain for the average backyard mechanic (and dangerous too because if you
> slip with the drill your could destroy the carb), another method that seems
> to work well is simply covering the entire existing bowl plug area with good
> quality epoxy. Make sure to clean and rough-up the area thoroughly before
> applying epoxy. Let the epoxy set for at least a whole day before
> reassembling the carb etc. I have epoxied carbs this way and found the
> epoxy to still be holding strong years later with zero leakage from the
> plugs. In general, you may just want to rebuild your carb and give it a
> full "blueprinting". This way you will know your carb is good.


I think I am going to replace the HEI module soon. Even if it's not
the problem (if there even is a problem) it sounds like it is a good
idea to replace it. Can a bad module also cause a miss? I've noticed
what may be a very slight miss, mostly in the 2-3K RPM range. Did not
really improve with the tune-up parts. I've also thought about
replacing the coil, too.

BTW, the engine and related is one of the GOOD points of this car.
Lately, I've had the rearend rebuilt and have replaced many of the
rear suspension and drivetrain components, etc. Rear wheel bearings
are next (I know - expensive) as well as a bunch of front-end stuff
like control arm bushings and possibly ball joints and tie rod ends.
I think the car sat for a long time under a carport before I bought it
and many of the bearings, seals and bushings on the chassis just
didn't take it well. It's only got 73K miles on it. Thanks for all
the advice.