Main
Page | Log In | LogOut | Register | My Profile | Active Users | Search

CorvetteforumC3
CorvettesCold
start issue

mg62
Senior
Member

185 posts [100%]
Toronto ON

Cold start
issue

7:52
PM 4/28/2002

When I do a cold start, she fires up reasonably
quickly (2 or 3 pumps, wait a couple of seconds, and then key
it with the foot off the pedal), but runs very rough for 10-15
seconds and then almost invariably stalls.

Then, a struggle to get her started again, she runs rough,
then smoother ... then OK. I've learned to let her run for at
least 5 minutes or so before hitting the road, and then I'm
good to go. On a warm start, she fires up immediately and
smoothly.

There's got to be a modus operandi for getting her to keep
running off the first start. Any insights on this would be
appreciated.

_______

Mark G.

1974 Corvette Stingray convertible 355 HP, 405 ft/lb
ZZ4 bought and
on the way, Holley Street Avenger
670 cfm and Dynomax Cerama-Coat headers
waiting to be
installed, 3-speed automatic
2001 Lincoln LS 3.0
litre 210-horse V6, 5-speed automatic
1999 Saab 9-3
convertible 2.0-litre 185-horse turbocharged inline-4,

5-speed standard (Saab soon to be replaced by

Jaguar XK8 convertible 4.0-litre 290-horse V8,
5-speed automatic)

A few more pictures of the Vette ....

American Boy
Senior
Member

150 posts [100%]
Quebec

Re: Cold start
issue (mg62)

8:54
PM 4/28/2002

I was having a similar problem with mine. Is
your carb a Quadrajet? In that case, my choke pull-off
diaphragm was torn. Your choke get your car to start and the
choke pull-off as the vacuum built, crack open the choke to
let breath your engine a little. It is located at the front of
the carb at the passenger side. Check when you start the
engine if the vacuum pull the diaphragm.

At least this is how it's made on my 1980. Hope this help.

Stephan

Buffalo Dude
Senior
Member

301
posts [100%]
Huntington Beach CA

Re: Cold start
issue (mg62)

9:21
PM 4/28/2002

Mine used to have that problem too. I'd have to
give it a little gas to keep it from dying and then it'd be
fine. Also had some problems with what I assume was moisture
in the exhaust. My car is parked outside
so when the hot pipes cool overnight, i
think moisture would get in and make it harder to start/run.
so I just make sure my car cover covers the exhaust pipes to
minimize moisture.

I would say check the obvious things: make sure spark
plugs/wires are still good, timing is right, etc. Haven't had
too many problems starting up after i tuned up my car(with a
little help from my uncle )
_______

'75 coupe, L48,
TH400, HEI, and now featuring a JVC 12-disc cd
changer!

Rockn-Roll
Senior
Member

1648 posts [100%]
Bellevue WA

Re: Cold start
issue (mg62)

11:38
PM 4/28/2002

Adjust your choke...it needs to be set Richer,
and/or the fast idle screw needs to be adjusted to increase
your idle. An idle of 1,000 - 1,200 is common when
cold.
_______

Rockn-Roll
75 L48 M20 4-speed with
69 sidepipes and Zaino.
Dynoed 203rwhp@4400rpm. Best 1/4
mile time 15.248sec @ 90.95mph

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (Rockn-Roll)

6:01
AM 4/29/2002

Thanks. I'll look into those possibilities.

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (American Boy)

5:37
PM 5/1/2002

quote:

I was having a similar problem with mine. Is your carb a
Quadrajet? In that case, my choke pull-off diaphragm was
torn. Your choke get your car to start and the choke
pull-off as the vacuum built, crack open the choke to let
breath your engine a little. It is located at the front of
the carb at the passenger side. Check when you start the
engine if the vacuum pull the diaphragm.

Yes, my carb is a Q-jet. I described this scenario over the
phone to my mechanic, and he diagnosed this same problem.

I'd be interested in some views on the "degree of
difficulty" of this issue. As I indicated on another recent
thread, I'm a complete novice with no skills and no tools. Any
chance I can fix this (with the knowledgeable input of this
Forum), or should I just open my
wallet?

_______

Mark G.

1974 Corvette Stingray convertible 355 HP, 405 ft/lb
ZZ4 bought and
on the way, Holley Street Avenger
670 cfm and Dynomax Cerama-Coat headers
waiting to be
installed, 3-speed automatic
2001 Lincoln LS 3.0
litre 210-horse V6, 5-speed automatic
1999 Saab 9-3
convertible 2.0-litre 185-horse turbocharged inline-4,

5-speed standard (Saab soon to be replaced by

Jaguar XK8 convertible 4.0-litre 290-horse V8,
5-speed automatic)

A few more pictures of the Vette ....

Rockn-Roll
Senior
Member

1648 posts [100%]
Bellevue WA

Re: Cold start
issue (mg62)

8:11
PM 5/1/2002

Should be very simple...the choke spring is
located on the intake manifold on passenger side of carb...the
housing pops off revealing the spring and screw. Fast idle
screw is located in that area as well on pass side of carb.

Just a thought, but have you tried to hold the pedal down
about 1/8 of the way...it will help trouble shoot...holding
the pedal down...or just tapping it just after it's started
will cure a problem of the choke linkage binding...in which
case spray some WD40 around the choke
linkage.
_______

Rockn-Roll
75 L48 M20 4-speed
with 69 sidepipes and Zaino.
Dynoed 203rwhp@4400rpm. Best
1/4 mile time 15.248sec @ 90.95mph

American Boy
Senior
Member

150 posts [100%]
Quebec

Re: Cold start
issue (mg62)

7:43
AM 5/2/2002

quote:

I'd be interested in some views on the "degree of
difficulty" of this issue. As I indicated on another recent
thread, I'm a complete novice with no skills and no tools.
Any chance I can fix this (with the knowledgeable input of
this Forum), or should I just open my wallet?

I could guide you trought the process, I just got a
digital camera that could give some good picture of it. It is
very simple to do. We just have to check if it is the real
problem and after it is a matter of ordering the right part
and installing it on the car (2 screws). If you can wait till
saturday, I will be glad to help (I work 12 hours a day till
then).

Stephan

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (American Boy)

12:37
PM 5/2/2002

Stephan, thanks. Let's get in touch on
Saturday.

If anyone else wants to pipe in on this issue with some
tips, please do.

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

3:41
PM 5/2/2002

American Boy is right. If it is the choke
pull-off it is one of the easiest fixes you can make on a
Quadrajet. I just rebuilt mine last weekend and have become
pretty familiar with its operation.
You can test the pulloff with a vacuum
pump but don't worry if you don't have one. Take the vacuum
hose off the back of it and attach a longer (2 ft.) hose,
preferably a brand new one because you are going to suck on
the hose to create a vacuum. You will see the pull-off
literally "pull-off" the choke. (This is a really clever name
don't you think?) If it doesn't pull-off, replace it. You just
saved yourself a $50 labor charge.
_______

1976 L-82; 4-spd;
3.70's; original Buckskin paint and Vega steering wheel
[

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

6:28
PM 5/2/2002

quote:

Take the vacuum hose off the back of it and attach a longer
(2 ft.) hose, preferably a brand new one because you are
going to suck on the hose to create a vacuum. You will see
the pull-off literally "pull-off" the choke. (This is a
really clever name don't you think?) If it doesn't pull-off,
replace it.

OK, thanks, I think I can follow that. A couple of
questions: (i) When I go to the auto parts place, how do I ask
for the hose? ("Er ... I need a hose to suck a vacuum outta my
choke pull-off thingy"); and (ii) What if, when I do what
you've suggested, it does, in fact, pull-off the choke?

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

7:03
PM 5/2/2002

Take the short hose off the pull-off and bring
it to the autoparts store. Buy maybe 2 feet of it. It is a
very standard size and many of the hoses connected to the carb
are this size so you can always put it to use later. If the
choke pull-off pulls off, then you have eliminated that as a
problem. You can also check it by haing someopne else start
the car and watching the pull-off afater the car starts to see
if it is working.
_______

1976 L-82; 4-spd; 3.70's;
original Buckskin paint and Vega steering wheel
[

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

8:43
PM 5/2/2002

If the choke pull-off is working, there is also
an adjustment screw near the top of the device. Turn the screw
and watch what is happening and you will see that it adjusts
the amount that the choke is being pulled by pushing back a
cam. If this looks alright ,check to see if the choke is
working. When you press down on the gas 1x and the car is
cold, the choke should close the flap on top of the carb. If
this all looks alright, then move to the fast idle screw. This
keeps the car running at a faster idle until it warms and is
kicked down. If your carb is like mine, the screw is well
hidden under the choke mechanism and is adjusted from the
front of the carb. It is hard to find and harder to adjust.
Not complicated, just hard to reach. All these adjustments
work together to make the carb work correctly. It is pretty
hard to mess this up. Just remember where things are adjusted
now and play around with it and get a feel for how the thing
works. You can always just put everything back and bring it to
a mechanic and let them mess it up.

If you still want to take this on, go to corvettefaq.com
and get Lars' paper on tuning the Quadrajet. Also get a
service manual or a Haynes manual will do, and it shows the
basics of these adjustments. If you decide you want to know
more, get Doug Roe's book on Rochester Carburetors.

_______

1976 L-82; 4-spd; 3.70's; original Buckskin
paint and Vega steering wheel [

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

7:21
AM 5/3/2002

Thanks for the detailed instructions. I really
appreciate it. (I may not fully understand what you've
written, but I appreciate it!)

Doing some further digging, I found a set of instructions
at the Champion Auto website for testing the choke pull-off
and installing a new one. It's a pdf file, tech tip #63 at:

http://www.championauto.com/championauto/techtips.html

Those instructions say that there's an adjustment that has
to be made (distance between choke blade and housing) after
you get the thing on, which require me to measure this
distance with a gauge and then have a Hayes manual to know the
car's specification, and then adjust it, either by turning
some screw or bending a linkage (huh?). This adds a level of
complexity that might be beyond my reach.

Sorry to be so dense about this stuff. As I said at the
beginning of this thread, more or less, I'm an idiot.

Marc78
Senior
Member

87 posts [100%]
New Orleans LA

Re: Cold start
issue (mg62)

7:35
AM 5/3/2002

Wow... that's strange. My car just
started doing the exact same thing. I'm we have some ideas to
pull from here...

_______

-Marc

'78 Silver Anniversary - My little project

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

7:37
AM 5/3/2002

When the choke sets (the flapper closes) they
are saying to measure how tightly it is closed. Basically, it
should be slightly open. The guage is slipped in next to the
flapper (non-technical jargon ) and this measures the opening. But if it
is generally closed it should start. The idea is that the car
gets a richer fuel mixture (more gas, less air), because that
flap is cutting off the air. Once it starts, the pull-off
pulls that flap open some, allowing more air to rush-in to
keep the car running. Your problem though sounds like the car
is either getting too much gas (because after the car starts,
the flapper is not being opened some by the choke pull-off) or
the pull-off is working and that fast idle screw I spoke of
which was hidden by GM engineers so as to keep its location
secret to the world, needs to be turned a couple of turns.

_______

1976 L-82; 4-spd; 3.70's; original Buckskin
paint and Vega steering wheel [

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

2:47
PM 5/3/2002

OK, here's the current state of affairs.

I tried to take the hose off of the choke pull-off, but
couldn't. It's just not moving, at either end. Great, ... I'm
a hopeless failure as a mechanic, right from the git-go.

So then, with the carb still exposed, I go to try to start
the car. I tap on the gas to set the choke. I see the choke
set. (There are three flaps on the top of the carb, and the
one that I'm calling the choke flap is the odd man out, longer
and narrower, closer to the nose of the car. The other two are
like twins, and they're closer to me in the driver's seat.
You'll have to excuse me for not knowing the technical terms
here.)

I turn the key, and she turns over and starts up. She only
runs for a few seconds before stalling, but during that time I
think I see two things. First, I THINK I see the choke
pull-off move. Second, I THINK that I do not see the choke
flap move with it.

What's further confusing about this is that the choke
pull-off does not appear to be attached in any way (directly
or indirectly) to the choke flap. There's a linkage between
the pull-off and the carb, but the thing that linkage is
attached to moves the two twin flaps, not the choke flap. In
any event, and I suspect this is important, when I manually
move the business end of the pull-off, it has no effect on any
of the three flaps on top of the carb. The linkage just moves
back and forth inside the little loop that it's hooked into,
without apparently causing anything else to move.

Dunno if the above is going to make sense to you guys, but
I'd appreciate your views on it.

My battery is now dead from all the recent cranking trying
to get 'er started, so I'm trickle charging
it.

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

4:08
PM 5/3/2002

Good. That is in fact the choke flap. It sounds
like everything is working correctly. The choke pull off does
not attach to anything except by the 2 screws that hold it to
the carb. It simply retracts and when it does it contacts a
lever that pulls the choke off. The long rod that goes to
apparently nowhere is for the secondaries - another subject
altogether so ignore it.

When you look at the big black dial on the choke side you
will see that it says richer-leaner. This controls the
duration of the choke by winding a spring inside. Loosen the 3
little screws on the perimeter of that dial and turn it some
toward rich - counterclockwise. Not too much. I also think
your fast idle screw needs to be turned in some. That is the
one hidden under the choke. If you take out the 2 screws that
hold the choke pull-off on you can see it a lot better. Try
giving that a couple of turns clockwise. That screw pushes on
a cam that is attached to a rod that opens the flaps under the
carb. (you can't seee them).
_______

1976 L-82;
4-spd; 3.70's; original Buckskin paint and Vega steering wheel
[

American Boy
Senior
Member

150 posts [100%]
Quebec

Re: Cold start
issue (R. Bruno)

9:56
AM 5/4/2002

Sometimes a picture is worth a tousand
words.

One things to check at the secondary airvalve; when the
engine is not running, the rod that goes to the secondaries
should be positionned as describe on the picture. You're on
the right track, keep on.

Stephan

[Modified by American Boy, 1:03 PM
5/4/2002]

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

10:19
AM 5/4/2002

Well, I'm hoping that I've reached a resolution
on this issue. I'm pretty sure that we're closer, in any
event.

I spoke to a gearhead friend this morning and he agreed
with the views expressed above. When I told him that the choke
pull-off appeared to jump when the car was started, he thought
that the choke thermostat probably needed to be adjusted (as
you've indicated, R.).

He suggested that I get the car running and bring it out to
his place to take a look at it, and he suggested a way to
accomplish this. With my battery ready to go from the
overnight trickle charge, I brought in my daughter as my
trusty assistant. I got her to hold a coat hanger in place to
keep the choke flap open just a bit while I fired it up. The
car started right away, and, with the air coming in from the
coat-hanger gap, ran smoothly while warming up. Once I got an
even idle without having to put any pressure on the pedal, I
took over the coat hanger. Eventually, after a few minutes,
the choke flap opened on its own wider than the coat hanger,
and I was able to remove the hanger.

I roared over to my friend's place, and he took a look. He
confirmed that there's nothing wrong with the choke pull-off.
He then showed me how to adjust the choke thermostat. We
turned it clockwise a little less than half an inch from its
previous position.

So I'll find out tomorrow morning, once she's cold again,
whether than much of a turn was enough.

Another note for others who may encounter this problem, or
even a failure of the choke pull-off. My choke thermostat is
electric and doesn't depend on the engine's heat to open the
choke. My buddy tells me that a work-around for this issue is
to turn the key to the "on" position (i.e., the position just
before ignition) and let it sit for 5 minutes or so. The car
will be fooled into thinking it's warmed up, and the choke
flap will be open enough to start the car smoothly --
essentially bypassing the choke pull-off and ignoring the fact
that the choke thermostat is wound too tight.

Many thanks to R.Bruno and American Boy for the time they
took in responding to my query on this point. I'll let you
know how it turns out after the cold start tomorrow.

Thanks also for the pic. Unlike a couple of days ago, I can
actually identify those parts now from direct personal
experience!

Well, it's a beautiful sunny day in Toronto today, so I've
got some road to tear up. Catch ya later.

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

3:44
PM 5/4/2002

Sounds like you've got it covered mg62. Wow-
that is a great picture alright. Someone should hold on to
that one for other questions. be glas you have an electric
choke. The old spring models (which I think would have been
original on your car) are a little more funky - but then thats
what makes it a Vette. Have fun.
_______

1976 L-82; 4-spd;
3.70's; original Buckskin paint and Vega steering wheel
[

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (R. Bruno)

9:09
PM 5/4/2002

mg62- if it is still a problem tomorrow it is
likely the choke pull-off that is out of adjustment. It is
adjusted thus:

1. With car cold and the choke flap closed, put vacuum on
that hose we talked about earlier. (Cut it off if you have to
and put a new one on when you are done. You can buy it for
about 10cents an inch at an auto parts store. Just bring the
old one.) Either suck on it or get a vacuum pump (a very
useful item to have around a Vette if you are in the mood to
spend a couple of bucks.)

2. The pulloff should open the choke flap. Put LIGHT
pressure on the flap (opening it a little more) to simulate
the air that will be wizzing past there as the engine is
running. The opening now in the flap should be 1/4 inch. If it
is opening wider, that is your problem. It is getting too much
air for a cold engine.

3. To adjust, keep the vacuum on the pull-off (now you are
glad you bought that vacuum pump) and adjust the screw you see
right there on top. As you do you will see the flap slowly
close. Get it to 1/4 inch and it will start right up and stay
running until the choke warms and closes.

Let us know how it turns out.
_______

1976 L-82; 4-spd;
3.70's; original Buckskin paint and Vega steering wheel
[

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

3:32
PM 5/5/2002

Thanks.

When I went out to fire her up today, I found that the
half-inch turn of the choke thermostat was probably too much.
She was getting too lean a mixture on a cold start, and
wouldn't engage.

I took off the air cleaner and I could see that she was
sitting cold with the choke flap open a bit, more than an
eighth of an inch, maybe a quarter? I hand-tapped the flap
closed, and she started up right away. As a result, I loosened
the screws on the choke thermostat and dialed it back
counterclockwise half the distance that we had dialed it
clockwise yesterday. I'll be able to tell on the next cold
start whether this worked.

Funny vignette. I was standing out in the front yard this
afternoon with my Vette proudly in the driveway, yakking with
a neighbour and complimenting him on his new Mercedes vert. He
asked me how things were going with the Vette, and I said
she's running great and sounding awesome, and "I'm tinkering a
bit with the carb". I stopped, and looked at him, and said ...
"Now there's a sentence I never thought I'd say ..."
Ha!
_______

Mark G.

1974 Corvette Stingray convertible 355 HP, 405 ft/lb
ZZ4 bought and
on the way, Holley Street Avenger
670 cfm and Dynomax Cerama-Coat headers
waiting to be
installed, 3-speed automatic
2001 Lincoln LS 3.0
litre 210-horse V6, 5-speed automatic
1999 Saab 9-3
convertible 2.0-litre 185-horse turbocharged inline-4,

5-speed standard (Saab soon to be replaced by

Jaguar XK8 convertible 4.0-litre 290-horse V8,
5-speed automatic)

A few more pictures of the Vette ....

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

4:37
PM 5/5/2002

Now your getting the idea! And when you think
about all the money your pissing away and the time your
wasting it makes victory even sweeter!
_______

1976 L-82; 4-spd;
3.70's; original Buckskin paint and Vega steering wheel
[

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

3:31
PM 5/6/2002

OK, here's the next installment in this saga.

Just went to try another cold start. Took the air cleaner
off to take a look beforehand while she's still cold and
unstarted just to see what was going on. The choke flap was
was wide open. It would not push down manually to a fully
closed position. I got behind the wheel and pumped the gas a
couple of times (thinking that would set the choke), to no
effect. Choke flap still open.

I figured ... hmmm ... the choke thermostat must still have
been adjusted too far clockwise. So I loosened the 3 screws
and turned it back almost, but not quite, to the original
position, which we had marked. Not sure what to do next, while
standing over the carb, I manually moved the throttle, and the
choke flap snapped shut. I got in the car, and she started up
and kept going fine.

Note: I'm not ignoring your three-point plan from a couple
of posts up above. As matters stand now, though, it seems to
me that the choke pull-off must be working ok, because when
the choke flap is down tight enough to give her a rich enough
mixture to fire up, the flap does in fact get opened to allow
her to continue to run.

What I don't understand is why the choke would not set when
I was pumping on the gas earlier. Any chance this last
re-adjustment I made will solve the
problem?

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

3:41
PM 5/6/2002

If the car is cold, the choke should shut (set)
with just 1 pump on the gas. Then once it starts the pull-off
should open it about 1/4 inch to keep it running. If it is not
setting, your turning it tighter should do the trick or thr
problem is that the linkage was/is binding. It is a long shot
but make sure the throttle linkage is not binding in anyway
and that it is clean and free of muck. Let us know how iot
turns out.
_______

1976 L-82; 4-spd;
3.70's; original Buckskin paint and Vega steering wheel
[

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

4:07
PM 5/8/2002

Here's the latest wrinkle.

Went to do my cold start, and she started up fine, and kept
running fine, for several minutes (with me applying light
pressure on the gas pedal to keep her revving above 1000). At
some point after least two and probably three minutes from
ignition, I took my foot off the gas to let her idle on her
own, and when she started to falter I put some pressure on the
gas, but the idle kept dropping, like she wasn't getting any
gas, and then she stalled.

Now, she won't start. Like she's flooded. Dang.

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

5:03
PM 5/8/2002

This is deja vu all over again. But really, it
sounds like the pull-off is not working correctly. If it is
opening too much it will do as you described because it is
getting too much air to keep running, which is why keeping
your foot on the pedal helps. Check to see that it is opening
about 1/4 inch when you put vaccuum on it. If the pull-off is
opening correctly as per the earlier comments then adjust that
fast idle screw. It is located near the choke linkage down
really low. It is hard to see at first. You may have to hunt
around or remove the 2 screws holding the pull-off any just
move it out of the way and you will see it. Turn it clockwise
a turn or so to raise the fast idle and see what you
get.
_______

1976 L-82; 4-spd; 3.70's; original
Buckskin paint and Vega steering wheel [

R. Bruno
Senior
Member

632 posts [100%]
San Francisco, CA

Re: Cold start
issue (mg62)

5:03
PM 5/8/2002

This is deja vu all over again. But really, it
sounds like the pull-off is not working correctly. If it is
opening too much it will do as you described because it is
getting too much air to keep running, which is why keeping
your foot on the pedal helps. Check to see that it is opening
about 1/4 inch when you put vaccuum on it. If the pull-off is
opening correctly as per the earlier comments then adjust that
fast idle screw. It is located near the choke linkage down
really low. It is hard to see at first. You may have to hunt
around or remove the 2 screws holding the pull-off any just
move it out of the way and you will see it. Turn it clockwise
a turn or so to raise the fast idle and see what you get. Is
the car idling ok when it is warm?
_______

1976
L-82; 4-spd; 3.70's; original Buckskin paint and Vega steering
wheel [

mg62
Senior
Member

185 posts [100%]
Toronto ON

Re: Cold start
issue (R. Bruno)

6:00
PM 5/8/2002

Went to start it again. After some hard
cranking (I'm probably doing permanent damage to the starter),
she started and ran for several minutes. She was just about
fully warmed up, and idling fine on her own. I got out, put
the air cleaner back on, closed the hood, got in, gave it a
short sharp rev ... and she bogged down and died.

Battery's drained again. Trickle charging ... again.

What I don't understand is what this could have to do with
either the pull-off (because it started initially and stayed
running) or the fast idle screw (because I was holding the
idle up myself with pressure on the pedal). It seems
vulnerable to this problem any time up until being fully
warmed up.

American Boy
Senior
Member

150 posts [100%]
Quebec

Re: Cold start
issue (mg62)

8:49
PM 5/8/2002

Make sure you didn't got the choke linkage
stuck. Do you have the stock air cleaner on there?

Something is not right, your carb is in problem. There's an
adjustement somewhere that is off. Do you have Lars paper on
Quadrajet? It could help you understand how it's working. The
thing is that not much mecanics fully understand these carb.
Even if you go to a garage, they'll get it all wrong. Maybe
you could try turning your choke assembly again. Hard to tell.
Good luck.

Stephan

[Modified by American Boy, 12:06 AM
5/9/2002]

» Return to C3
Corvettes

Forum Jump 50th
Anniversary Events Audio/Electronics Autocrossing
& Roadracing Babes Breathless Performance C1 &
C2 Corvettes C1 & C2 Parts
C1s & C2s for Sale/Wanted C3 Corvettes C3 Parts
for Sale/Wanted C3s for
Sale/Wanted C4 Forced
Induction/Nitrous C4 General
Discussion C4 Parts for
Sale/Wanted C4 Tech/Performance
C4s for Sale/Wanted C5
Forced Induction/Nitrous C5 General
Discussion C5 Parts for
Sale/Wanted C5 Tech/Performance
C5s for Sale/Wanted C6
General Discussion Car Care
Products Corvette Accessories
Corvettes of Houston Cruise Control Auto Die Casts
& Collectibles Drag Racing
ECM/PCM Tuning Engine
Mods Exit 28 Motorsports
F-Body General Discussion Factory Correct Resto Great
Lakes Help Forum Ken's Newsletters Kill
Stories LAPD Moderator's Corner Mountain -
Prairie National Events News and Politics Northeast Off Topic
Other Cars Other
Country Events Pacific Regional Coordinator's Forum Southeast Southwest
T Byrne Motorsports Testing West Coast
Corvettes Wheels & Tires
Xtreme Motorsports Z06
Discussion Zip Products Section
ZR1 Discussion

Powered by zeroforum 2.0.4 b1.
©2001 zeroforum.com.

C5
FAQ
CF
C5 Registry
CF C4
Registry
Performance
Reg
Neighbor
Locator
Corvette
Events
Event
Galleries
CF Name
Tags
Product
Reviews
Tech Tips

Home
Pages
Corvette
Portal
Corvette
Clubs
Vanity
Plates
Race
Sites/Tracks
Vendor Sites

Forum FAQ

Moderator
Bios
Advertising

Wuname

Risk free
trial