[455HO75]

My rebuilt 75 455 is struggling to run. Carb was rebuilt, but it has a very hard time starting and then running. My tech says you can't find any parts for a Quad anymore. It seems to me at first glance this is not so. I have tried to log on to Cliff's but have not had any replies allowing me to join and hence see what they can offer for my Quad.

Looking to see if someone here is on that forum and can see if they can ask why no replies, been 5 or so days, generally this happens right away

[455HO75]

https://cliffshighperformance.com/si...orum/index.php

[b-man]

Cliff sells still parts and kits for Quadrajet carbs.

You should contact him directly, the phone number is right here on this page at the bottom.

https://cliffshighperformance.com/

People get busy with other things and sometimes go on vacation, hence no quick replies on the forums there.

[graygator]

Call Cliff. Buy his book. He sold me parts in 2024 to rebuild my Quadrajet and recommended jets and metering rods specifically for my application. He took a fair amount of time on the phone to discuss it with me. And you don't want just any parts, for example you want the good accelerator pump he sells that will hold up to modern fuel.

[RocktimusPryme]

Ive never used to the forum, but I called to order parts a couple months ago and go great service on the phone, which required very little on my part. Gave him the carb number, and general goal. He styled me with everything I needed and sent it to me.

[indymanjoe]

I use his forum but i also just call him if needed.

[steve25]

Your motor has a hard time starting when , Hot or cold?
It does not take a much of a functional carb to start a cold motor!

It takes a lot of fuel and a choke that works..
Starting a cold motor takes just about the reverse of a hot idle air to fuel ratio.

Instead of 14 parts air to 1 part fuel a cold motor needs darn near the opposite.

On a cold motor once the outside temps get down below 50 the choke must close all the way once you have hit the gas once before cranking the motor.

Once the motor starts and is a high idle the choke should be open the diameter of a 1/8” drill bit for starters.

This means the choke pull off needs to work .

This is a very easy thing to to test because the motor does not even need to be running.

[VCho455]

Originally Posted by steve25

Your motor has a hard time starting when , Hot or cold?
It does not take a much of a functional carb to start a cold motor!

It takes a lot of fuel and a choke that works..
Starting a cold motor takes just about the reverse of a hot idle air to fuel ratio.

Instead of 14 parts air to 1 part fuel a cold motor needs darn near the opposite.

On a cold motor once the outside temps get down below 50 the choke must close all the way once you have hit the gas once before cranking the motor.

Once the motor starts and is a high idle the choke should be open the diameter of a 1/8” drill bit for starters.

This means the choke pull off needs to work .

This is a very easy thing to to test because the motor does not even need to be running.

All this x2. I am a believer in the old adage "90% of all carburetor problems are electrical".

What is the voltage at the coil while cranking the engine and when its running?

Was the engine starting and running good after the rebuild and then it changed to the current state?

Or has this been an ongoing issue since the rebuild?

[BLUE TA]

hi, I use cliffs forum there is a ton of great info on it. BLUE TA

[burd]

Yep
Instead of posting car isn’t running rite, what’s your guess, go rite to the man.

[steve25]

Cliff is going to ask for more info just like we are, which did not seem to be presented by the OP forcing us to use our collective crystal ball.

[sdbob]

I've bought his book which is very helpful.(before I had bought Doug Roe's book on qjets learning what I could)),his carb parts are in my street car and race car. I'm very pleased. Always straight forward with his help.

[Shiny]

Be patient, Cliff's QJet forum is a resource worth the wait.

If you read the attached post, he gets blasted by spammers just like PY, so that chore may not be one of his favorites. Given his stated efforts to enjoy more life and less work, I wouldn't blame him for monitoring and processing those account requests less than instantly.

[455HO75]

All, Thanks for the helpful replies. I went out and grabbed my Q-jet ID # 7055261 PR 645.
My carb experience is more managing small engine carbs (tractor, lawnmower). I'm unfortunately am more of bolt-off, bolt-on mechanic. Really good at tearing things apart, LOL

[jhein]

Just pick up the phone and call Cliff. I'm nobody special to him but whenever I've spoken with him on the phone he's been super nice and unbelievably helpful. He didn't just sell me parts, he gave me invaluable advice.. Great guy.

[Kenth]

Originally Posted by 455HO75

All, Thanks for the helpful replies. I went out and grabbed my Q-jet ID # 7055261 PR 645.
My carb experience is more managing small engine carbs (tractor, lawnmower). I'm unfortunately am more of bolt-off, bolt-on mechanic. Really good at tearing things apart, LOL

Looks like #7045261 PR 1645.
For late 1975 Firebird 400.

[Half-Inch Stud]

Been to the site. But i got better service showing up to his brew pub with 4 Q-Jets bodies for recolor, and them rebuild kits.

[tremo]

Here are some other good resource I found helpful for guidance and to purchase parts when I rebuilt my Q-Jet. Don't be afraid to take the plunge. It's the best way to learn!

https://quadrajetpower.com/

https://www.youtube.com/@QuadrajetPowerLLC

https://www.carburetion.com/quadrajet.asp

[Cliff R]

It is best to call the shop to order parts as mentioned.

I have to approve all applications to the Forum, PM me with the info that you used and I'll approve the application.....

[455HO75]

All, Thanks for the helpful replies. I went out and grabbed my Q-jet ID # 7055261 PR 645.
My carb experience is more managing small engine carbs (tractor, lawnmower). I'm unfortunately am more of bolt-off, bolt-on mechanic. Really good at tearing things apart, LOL