Cadillac & LaSalle Club Discussion Forum

Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Tommy on October 06, 2009, 12:46:57 PM

Title: STILL WON'T START WHEN COLD
Post by: Tommy on October 06, 2009, 12:46:57 PM
I'M AT IT ONCE AGAIN. EVERY MORNING I HAVE TO POUR GAS IN THE CARB TO GET IT STARTED, IT WILL FIRE UP THEN STALL AND WILL DO THIS 4-5 TIMES UNTIL I START PLAYING WITH THE GAS PEDAL AND THEN IT FINALLY KEEPS RUNNING. DOES THIS SOUND LIKE I'M LOSING THE PRIME ON THE FUEL PUMP OVERNIGHT??? BECAUSE ONCE IT GETS STARTED IN THE MORNING THE REST OF THE DAY AND NIGHT IT STARTS WITH A CLICK OF THE KEY? THEN WHEN MORNING COMES IT'S BACK TO PUTING GAS IN THE CARB AGAIN.  THANK YOU
Title: Re: STILL WON'T START WHEN COLD
Post by: Mike Josephic CLC #3877 on October 06, 2009, 03:58:15 PM
What year car and carb are we talking about?  What you describe was a common problem
with some Rochesters that would let the carb fuel bowl drain back out after sitting.  You
then had to crank like heck the next day to get it started.

Mike
Title: Re: STILL WON'T START WHEN COLD
Post by: tommy on October 06, 2009, 04:33:43 PM
I have a 1970 cadillac 472 with a new carb 2 years ago. THANK YOU
Title: Re: STILL WON'T START WHEN COLD
Post by: Dave Shepherd on October 06, 2009, 07:11:06 PM
Yup Quadaret, the bowl base plugs were known for leaking, we fixed plenty and still do.
Title: Re: STILL WON'T START WHEN COLD
Post by: The Tassie Devil(le) on October 06, 2009, 07:17:35 PM
Make sure the Choke is working properly, as these carbies need a very rich mixture at initial start-up.

Bruce.   >:D
Title: Re: STILL WON'T START WHEN COLD
Post by: Tommy on October 06, 2009, 07:25:00 PM
Quote from: Dave Shepherd on October 06, 2009, 07:11:06 PM
Yup Quadaret, the bowl base plugs were known for leaking, we fixed plenty and still do.
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What needs to be done?? The car only has 2000 miles on it. Nothing leaking outside motor is dry? THANK YOU  Tommy
Title: Re: STILL WON'T START WHEN COLD
Post by: Glen on October 07, 2009, 01:47:50 AM
First check the choke. 

First thing you do in the morning is open the hood and remove the top of the air cleaner.  The choke plate should be wide open (you should be able to look down into the carb). 

Now using the throttle linkage open the throttle about half way.  The choke plate should snap closed. 

If it does not then you have a stuck choke and it will make the car hard to start when cold. 

My S10 pickup has that problem.  I have to clean it every 3 to 6 months.  I don’t bother any more, I just pump the throttle continuously until it starts.   

Glen
Title: Re: STILL WON'T START WHEN COLD
Post by: Tommy on October 07, 2009, 06:29:46 AM
Quote from: Glen on October 07, 2009, 01:47:50 AM
First check the choke. 

First thing you do in the morning is open the hood and remove the top of the air cleaner.  The choke plate should be wide open (you should be able to look down into the carb). 

Now using the throttle linkage open the throttle about half way.  The choke plate should snap closed. 

If it does not then you have a stuck choke and it will make the car hard to start when cold. 

My S10 pickup has that problem.  I have to clean it every 3 to 6 months.  I don’t bother any more, I just pump the throttle continuously until it starts.   

Glen

The choke is working fine. It has to be something else???  THANK YOU
Title: Re: STILL WON'T START WHEN COLD
Post by: jaxops on October 07, 2009, 08:04:38 AM
Very frustrating!  How are your carb floats doing?  I had the opposite problem where my floats drowned the carb because one of them had a leak and filled with gas resulting in the carb overflowing on the hot engine.  Nice huh?  Even though it was overhauled, it may not be set up properly.  Check and recheck everything.  Fuel pump output, carb settings, everything.
Title: Re: STILL WON'T START WHEN COLD
Post by: 76eldo on October 07, 2009, 08:24:13 AM
I would send the carb out for a full rebuild by someone who knows Q-Jets.

Brian
Title: Re: STILL WON'T START WHEN COLD
Post by: Rob Bruining CLC # 12428 on October 07, 2009, 09:07:03 AM
When the car is cold take the air cleaner off. Hold the choke plate open. Shine a light into the carb opening. Have someone else push the gas pedal down. You should see a squirt of gas in each opening. If no squirt then do the same procedure  once you can get the car running. If there is now a squirt then the bowl is leaking fuel overnight. If still no squirt then your accelerator pump (inside the carb) is defective and needs replacing. That would be much less than a whole new rebuild. Hope this helps.
Title: Re: STILL WON'T START WHEN COLD
Post by: tommy on October 07, 2009, 12:41:21 PM
Quote from: Rob Bruining CLC # 12428 on October 07, 2009, 09:07:03 AM
When the car is cold take the air cleaner off. Hold the choke plate open. Shine a light into the carb opening. Have someone else push the gas pedal down. You should see a squirt of gas in each opening. If no squirt then do the same procedure  once you can get the car running. If there is now a squirt then the bowl is leaking fuel overnight. If still no squirt then your accelerator pump (inside the carb) is defective and needs replacing. That would be much less than a whole new rebuild. Hope this helps.


CHOKE CLOSES WHET I HIT THE GAS. I GOT THREE QUIRTS AND THAT WAS IT NO MORE. WENT TO START IT IT NOTHING.STARTED POURING GAS IN THE CARB 4-5 TIMES EACH TIME SHE WOULD START THEN STALL. THEN FINALLY I STARTED PUMPING THE PEDAL TILL SHE CAUGHT AND WAS ABLE TO KEEP IT GOING. THE END. WHAT IS GOING ON ??  thank you
Title: Re: STILL WON'T START WHEN COLD
Post by: Otto Skorzeny on October 07, 2009, 01:05:48 PM
I think your accelerator pump is shot.
Title: Re: STILL WON'T START WHEN COLD
Post by: tommy on October 07, 2009, 02:50:45 PM
Quote from: Otto Skorzeny on October 07, 2009, 01:05:48 PM
I think your accelerator pump is shot.


iT SEEMED LIKE AIR WAS PUMPING AND NOT GAS. I COULD HEAR IT AND SAW NO GAS SOMETIMES I GOT A DROP.
Title: Re: STILL WON'T START WHEN COLD
Post by: Otto Skorzeny on October 07, 2009, 03:15:24 PM
If you determine that your carb needs to be rebuilt, click on the link below my name and find Daytona Parts company. They do a fantastic job rebuilding carbs. You can also call them for help over the phone.

Title: Re: STILL WON'T START WHEN COLD
Post by: The Tassie Devil(le) on October 07, 2009, 07:25:20 PM
Sounds like the Accelerator Pump to me.

BUT, if you have to prime it 3 times before it will run, then I am sure that your Bowl is dry.

Bruce. >:D
Title: Re: STILL WON'T START WHEN COLD
Post by: Mike Josephic CLC #3877 on October 07, 2009, 11:01:04 PM
I have to agree with Forrest's earlier comment -- get it rebuilt by somebody who
knows the Rochester Q-Jets.  Then, your problems should be over.  All the symptoms you
describe point to problems with that carb.

Mike
Title: Re: STILL WON'T START WHEN COLD
Post by: Wayne Womble 12210 on October 08, 2009, 01:27:09 AM
As stated before, Q-jets are notorious for this.  The well plugs need to be fixed to keep it from draining out.  In the mean time, before you do anything else. When cold, hit that pedal 10 or so times in rapid succession, then turn the key.  If it starts, pump like crazy to keep it going until the gas gets up.