AZ455

The car runs great at all speeds and throttle. Once it's moving if I push it to the floor it just accelerates like a bat out of hell. It's a 74 Delta 88 455 4bbl.

The only problem I am having is if the car is stopped, idling in gear, and I romp on it it'll bog pretty bad then once it recovers we're flying again. Fuel filter is new, no vacuum leaks anymore as far as I can tell.

Sound like a lean condition going from stopped idle to WOT? I was thinking maybe the secondary air door at the top were opening too fast? There doesn't seem to be anything holding them closed except the vacuum controlled linkage. When the engine is off I can push them open all the way and they stay there. Should there be a spring return or something?

Thanks.

MDchanic

The secondary air valve doors should definitely be spring loaded and should not stick.

As for the bog, there are many possibilities, including a bad accelerator pump, lean idle settings, and bocked transition ports.

From the sound of it, though, it seems like time for a rebuild, which should take care of all of that.
Get a rebuild kit from the local parts store for $20 (maybe spring for an extra $10 for the float), and follow the instructions in the kit and your Chassis Service Manual.

- Eric

72 cutlass455

Sounds like it could be the accelerator pump on the carb. It gives a extra squirt of fuel to prevent the flat spot on take off.

Rickman48

If you can find a rebuild kit for under $40, let me know! [if at all]
Last one I got, for a '65 442 was $39.95, and took me 3 days to find!
Auto Zone and Carquest said they were 'discontinued'! Found an independant that had one on the shelf, albiet very dusty!
I believe there's an adjustment on that secondary air door, simular to the Q-jet.
Might need an allen wrench and a small screwdriver.
If it was the accelerator pump, you'd have to prime it to start it!

AZ455

Thanks for the input guys. First thing I will look at is the air door spring being the cheapest attempt at a fix... At the moment it feels like there is NO spring. If the door is pushed open it stays there, but doesn't feel hung up, it'll close again real easy too. From what I understand the adjustment is somewhere on the right side of the carb near the secondary linkage with a screw on top and an allen underneath.

Anyone got a pic of the area? I know what to look for, but it'd make it easier.

MDchanic

Okay that's just weird.

I bought one for a QuadraJet about two or three months ago from my local Advance Auto Parts for, I believe, $18.95, and it took them one day to get it in.
It was the standard type kit that I first used around 1980, with everything but the float included, and the little cardboard measuring square and the folded instructions sheet.

Maybe I just got lucky.

- Eric

AZ455

https://classicoldsmobile.com/forums/187964-post13.html

This is pretty much what I am looking for in the very first pic, right?

My AutoZone showed the rebuild kits anywhere from $45 to $60. Though not sure they're for this model anyway. I'll look into it more down the line. Hoping for an inexpensive solution right now.

MDchanic

Bryan, I say the same thing to every person who posts any question at all and I sound like a broken record, but get a $#%&# manual!

You don't want to be messing around with your carburetor on the basis of some polaroid that some mook snapped of his improperly set-up car (present company excluded, of course ).

In the meantime, here's some light bedtime reading...

- Eric

Rickman48

A '64 has a 4GC - Q-jet kits are still around, although in generic form, since they were used well into the '90's!
The last one I got even had gaskets for the CCC carb!
And I've never seen a broken secondary air door spring, but have seen a loosened set-screw, that locks the adjustment!

AZ455

Thanks Eric,

I will definitely give that a read. I usually do have a factory service manual for whatever car I am working on if it's something touchy like this. Most are not carbureted though..

I'll keep ya posted on how it goes. Most likely wont have time to mess with it until Monday or Tuesday evening.

MDchanic

Well, yes, but that's my point. Though your '65 had a 4GC, his '74 has a QuadraJet, and it should be no problem for him to get a kit for it and clean it up.

- Eric

Rickman48

Woops - not awake yet, as the storms kept me up 1/2 the night!

Secondry air door has a small allen setscrew under the top plate, on the passenger side. It locks the adjustment screw visable from the side of the carb.
Unlock the screw, and turn it clockwise to tighten, but go small amounts - too tight and it won't open at the right time!
You have to lock it with the setscrew after each adjustment, as it'll 'unwind' if you don't!
Little trick if you're letting a teenager drive the car - crank it so it doesn't open!!

AZ455

That's some good advise! I don't have to worry about that though... and if I did, I doubt they'd be driving it anyway.

AZ455

Well I took a look at the secondary tension spring today, turns out it wasn't attached to anything. Hooked it back up and followed directions in the service manual to adjust.

The motor no longer feels like it wants to die if I push the pedal to the floor in gear, but it still doesn't feel like there is much power from a stop. If it is rolling, even 5mph or so, and I floor it, it'll get up and go. Maybe I just need to get a carb rebuild kit.

I've never had a car with an engine this size, I kind of thought it'd lay some rubber. Though it is a heavy beast... and likely needs some more tuning. I just need the cash for parts!

MDchanic

Remember, these cars were not bought by people looking to burn rubber - they were bought by successful but not pretentious little old people, like doctors and businessmen, who wanted a smooth, quiet, comfortable car, without attracting attention like a Caddy would. It's probably got a very tall rear end, and that, combined with the emissions detuning in '74, might make more than a chirp impossible, unless you're running bias tires.

- Eric

Rickman48

Where's your initial timing set?
Usually more timing will increase the bottom end torque, unless the chain is stretched.

Jetstar 88

For the rebuild kit, I'd go with these guys:http://www.carbkitsource.com/carbs/t...jet-index.html

TripDeuces

You realize you don't have a choke plate on it? Do you hold the pedal down to warm it up?

MDchanic

Sonofagun.

Good pick up.

It wasn't a deal breaker in the shot taken on the bench, but there's one of it installed, and you can just see the angle of the barrel, where you should only be able to see the choke plate.

Bravo.

- Eric

AZ455

Are you referring to the pics of the carb in the link I posted? I noticed it had no choke plate, however that one isn't mine. Just one I found on CO by another member to use for reference. Easier than snapping a pic of my own before leaving for work...

AZ455

This is something else I want to check. I'm going to get a tachometer most likely next week before I get into timing.

TripDeuces

Ah, my mistake then. Not that that would have caused your bog but just an observation. Many things can cause bog. Here's a good reference sight to take a look at. Accelerator pumps get a lot of bad hype but there are several other things to look at.

http://www.thecarburetorshop.com/Troubleshooting.htm

AZ455

Thanks for the link, good reading on there.

I am going to test the accelerator pump with the method on that site. If it passes I'll move on.

I see there are 2 lengths available, and the longer pump assemblies are usually '76 and newer Q-jets according to quadrajetparts.com. I'll measure mine to play it safe if it turns out I need one.

AZ455

So I tested the accelerator pump with the method on The Carb Shop website.

I get one stream from the pump jet. It says it's usually 2 streams from a 2 or 4 barrel. It doesn't seem like that healthy a stream in my opinion, though I really am not sure. It's just a quick single squirt and doesn't seem to even squirt out that steadily, sort of interrupted as the plunger goes down, if that makes sense. Maybe it is actually at fault this time. Should there be two steams from the single jet or are there supposed to be 2 jets?

TripDeuces

Makes perfect sense. You should see two streams, on on each side, left and right. Looks like you have a clogged passage. The streams are fairly forceful so seems like more clogging going on. GL

MDchanic

Should be a good, forceful, steady, decisive spray, one in each primary barrel.

- Eric

Mark71

Dang it... I found this thread just a little too late. I'm in the middle of rebuilding my first carb, a 73 Q-jet. I think I have pics from every $*&#@ angle possible.

Anyhow, I got a rebuild kit for mine (7043256) from Napa for $21.99. Add a float for 10 bucks and it is still a good deal. I don't know how to judge the quality of the gaskets besides saying that they look a lot better than the old ones. Kit has pretty much everything you need (and more). All the parts are Made in USA.

I did clean-the-heck out of the carb, but it wasn't too dramatic. Don't overdo it - it was a waste of time trying to get it perfect. I also did the whole epoxy the fuel well plugs thing. Not too bad.

If you need pictures or part numbers or whatever let me know.

Oh yeah, that looks like a Chevy carb with the right-angle fuel fitting. I figure the parts should be similar, though...

Mark

AZ455

Thanks for the part numbers from Napa Mark. That's most likely what I am going to do eventually. The car runs pretty damn good though, so it's not a huge priority right now. I don't plan to drive it like a drag car all the time anyway, I was just having some fun when I noticed the bog from idle to WOT. I fixed the bog by connecting and adjusting the secondary plates tension spring.

I am so used to driving my Toyota truck that the car feel like a rocket. When it's moving already and I give it some more throttle it'll sink ya into the seats a bit.

Upon looking closer I am getting a stream from the accelerator pump in both primary barrels. I missed the passenger side one before, while standing on the drivers side it's hard to see into that barrel.

That is a Chevy carb in the photo, but it's not mine. Mine is an Olds Q-Jet. I only wish my engine bay was that clean...

My main priorities with the car right now are: get a tach, check and adjust timing if needed, get new tires, fix leaky trans front pump seal. I already replaced the trans pan gasket and o-rings which cut the ATF leakage in half. Now it just pools in the converter cover over long periods of time and dribbles out the hole when I back down the driveway. It'll all get fixed in good time. I'll have access to some hoists again soon to make this stuff easier.

Mark71

Sorry, I misread earlier (I was working on my carb when I read your message!!!). I was gonna say, man, that is one clean engine compartment...

Sounds like you and I have some similar priorities - except the trans seal. My trans seems ok (knock on wood). I checked my timing and I am at 4* BTDC. Supposedly, I'd be better off at 7 or even 8...

Anyway, good luck and when you do that trans pump seal, please take and post the pictures. Some of us have never done that before.