FlyingV5150

Im having what i feel is a bunch of engine issues. I have a 1972 cutlass supreme with what i believe is the original 350.

First, its been colder cause its winter so the car takes a few tries to start. It usually starts then almost immediately shuts off again and i have to start it again. Not sure if this just cause of the temperature or what but its not a huge problem, as usually after 2 or 3 tries it stays on. But after it does start it kind of lets out a huge smoke screen. I live on a main street and have literally seen people drive around the billowing cloud it lets out sometimes. Doesnt seem normal.

More concerning to me though is something that has been happening the past couple days. Seems like when i step on the gas, the car sputters and hesitates a moment before going. Happens mostly when i accelerate from a dead stop, once it is going it seems better, and after driving it for a couple miles it isn't as bad but its still noticeable. Also when stepping on the gas the engine sounds audibly sparky/rattly (not sure how to describe the sound).

I'm at a loss really, I'm not real savvy when it comes to cars so absolutely any help i could get would rock. Let me know if any more information is needed and if it helps i can attempt to make a video detailing the problems, thanks everyone.

MDchanic

Is your choke working?

- Eric

oldcutlass

What have you checked so far?

76olds

Does the cloud of smoke smell like burnt Oil ?

FlyingV5150

Eric- Yes i believe my choke is working

Other Eric- I haven't really checked anything yet because i am not sure what to check, like i mentioned major newb here

76Olds- Smoke does not smell like oil

MDchanic

Okay, to rephrase: When cold, does your choke close all the way after you press the gas pedal to the floor one time, then does it open a crack as soon as the engine starts, then does it open fully once the engine is about a quarter to halfway warmed up?

- Eric

tru-blue 442

Do you knw how many miles
are on the engine, and has it ever
been apart for say a timing chain?

jaunty75

It sounds like the first thing to do is a good tune-up. Plugs, points, condenser, rotor, coil, maybe plug wires, set timing, dwell, idle speed, it's all in the book. If you're uncomfortable trying to do this yourself, have a trusted shop do it.

What color is the smoke?

FlyingV5150

Eric-I know the choke closes after pressing on the pedal but i haven't observed it during starting, something i need to do

tru-blue-Engine has almost 94,000 miles on it and i don't believe it has been apart, at least as long as i have had it, which isn't that long.

Jaunty-Smoke looks white. I bought the car about a month ago now and am not real comfortable doing some things, i could replace spark plugs but timing and all that i am not sure of. I have no idea who to take it to around here though, i would definitely want someone who knows what they are doing.

tru-blue 442

If the engine is cold now,
step out and have a look down in the radiator.
How far down is the coolant? White smoke could
indicate blown H/G or intake manifold gasket.

jaunty75

It sounds like the short and simple of it is that what it will take to fix the car is more than you're comfortable doing on your own. You might not know right now who in your area might work on it, but maybe you could ask around. Tune-ups are not complicated, and any competent shop should be able to do it. Heck, take it to a GM dealer.

White smoke could be coolant in the gas. I would check the radiator level as suggested.

A good mechanic should be able to do a compression test on all of the cylinders. If you do have a blown headgasket with coolant leaking into one or more of them, the bad ones should show up as having reduced compression.

As I say, find a good shop, and take the car there. The little odds and ends of advice being offered up here aren't likely to get you anywhere if you aren't comfortable actually doing any of the things suggested.

MDchanic

Well said.

- Eric

oldcutlass

Where do you live?

FlyingV5150

@Eric, Northeast PA, ugh...this is frustrating.

I saw there is a combustion leak tester that could tell me if combustion gasses are getting into the cooling system, would this tell me if the head gasket it bad? Seems like alot to spend on something i probably wont use that often.

http://shop.advanceautoparts.com/web...ter#fragment-1

tru-blue 442

Did you check your fluid level
in the radiator? May have to use a flashlight
to see all the way down.

MDchanic

How about just doing the basic diagnostics we suggested? We still don't know if the choke is working properly.

- Eric

tru-blue 442

Good point, it could just be flooding out possibly.

FlyingV5150

Ok so i checked it out and my radiator fluid looks good, the choke on the other hand does not seem to be working right. After pumping the pedal, doesn't seem like the choke does anything. And after starting, the choke stayed completely open. There is a loud sucking noise, like there is a vacuum leak or something. Does this help at all?

MDchanic

Is the loud sucking noise coming from the carburetor throat?

Is the choke butterfly fixed in position, or is it flopping around?

What model carburetor is this, and what sort of choke mechanism?

And... Can you post a few pictures?

- Eric

76olds

These guys are your best friends rite now flyingv5150. Better than any shop advice at this point for diagnosing your problems. Try to go with all the support you have here before you take it in and come out $$$ spent just my take on this. If you get too frustrated someone has started a good Yoga thread to relax in. Good luck with your car!!

69442C

Also, clarify the white smoke. Does it smoke all the time? Is this smoke different that what you would see from another car when first started in cold weather? Trying to see if this is normal exhaust vapor or something more serious.

Seems like the choke is not working and the stumbling could be an accelerator pump problem in the carb which would require a rebuild or have you buy a unit that has already been rebuilt.

oldcutlass

I agree the choke is probably inop. We need to know the source of your perceived vacuum leak? Perhaps a few pictures of the top of your engine?

69442C

Something else to check regarding the smoke would be the transmission modulator assuming your car has an automatic transmission. See if your car has a metal line that runs up the back of the passenger side of the engine and would eventually connect to a vacuum port on the intake manifold or the carb. There will be a small rubber hose to make the connection from the line to the vacuum fitting. If so, see if you can pull that line off and see if there is any oil in the line which would be transmission fluid if present. It should be dry so if there is trans fluid present, then the modulator on the trans went bad causing trans fluid to get sucked into the intake manifold and it is being burned with the air/fuel. Trans fluid with create a white cloud if it is mixed into the air/fuel going to the cylinders. If the small rubber hose on the line hose is original it may break so be prepared with a new piece just in case.

FlyingV5150

69442C-The smoke is super heavy upon start up, it does dissipate after driving it a short while though and it seems more normal.


Eric-Its a quadrajet, not sure what model, with what I believe is a hot air choke, and it looked like the butterfly just stayed in one position and didn't move at all


I'm gonna get some pictures asap, ill try and post a bunch but if you guys need me to focus on a particular area or photo something else I can easily do that.

oldcutlass

Vacuum lines, and all sides of the top of the manifold.

FlyingV5150

Got some pictures

DSC_0480_zps646624b9.jpg

DSC_0478_zps6a40e33f.jpg

DSC_0477_zps15c9fd79.jpg

DSC_0473_zpsdefa6ab4.jpg

DSC_0474_zpsac25561b.jpg

Hope at least some of these are helpful, i also plan on making a video of it starting, show you all what i am talking about with the smoke and everything.

steverw

Engine looks pretty clean, that sparky rattle thing you describe sounds like a timing problem to me, carburators do suck air so maybe thats all your hearing. Old motor cold starts with smoke maybe valve seals. But as much smoke as your describing maybe a combination of things, flooding,valve seals, timing off. If your accelerator pump is working then pumping it too much will flood it, just one firm push on the accelerator to the floor is all thats needed to set the choke. If its working. And again if its real cold it may be tempermental until the motor warms up a bit. Someone added an HEI dist.
Good luck
Steve

rcrac3r

[QUOTE=Its a quadrajet, not sure what model, with what I believe is a hot air choke, and it looked like the butterfly just stayed in one position and didn't move at all.[/QUOTE]

I would start with your choke. When cold, can you open the throttle a bit & move the choke butterfly by hand easily, maybe it's sticky from corrosion etc. The choke spring may just need adjustment . Loosen the 3 screws holding it in the housing, & again with the throttle open about 1/4 way, turn the black spring housing until the choke just closes, then tighten the 3 screws. Try starting it & the vacuum operated choke pull off should open the choke just a bit & the engine should run at a high idle. As long as the choke spring is working, getting hot air etc, after about a couple of minutes or so you should be able to touch the throttle to "kick the choke off" & open the butterfly fully.

joe_padavano

Two things from the photos. First, while that may be the original 350, the HEI distributor is decidedly not original. You need to find out what advance curve is in it to properly diagnose any spark knock problem. Second, that's not the original carb, in fact it appears to be a late-1970s or early-80s Chevy carb (note the Torx screws on the air horn, not regular flat-blade screws). Again, you need to understand how it's set up to properly diagnose your problems.

oldcutlass

It looks ok from the pic's. I would find someone to go over the tune and set your choke properly. An Hei distributor will not use the standard timing settings, so you need someone familiar with how to set it to work with your engine? The only thing I see is possibly the thermal vacuum switch on the front right of the manifold has been bypassed. It should not matter though.

joe_padavano

I have to disagree. While there's nothing glaring, the hoses and lines are not run as stock. This is due to the non-original carb, but I can't tell by looking at it that everything is connected properly.

What is the carb ID number off the driver's side of the carb? That will tell us what it came off of originally.

Also, I'd fix that, er, "retainer" holding the accelerator cable to the throttle arm on the carb. What is that, a square nut with tie wraps?

455man

I thought it looked like an 80s chevy carb too. Does it look like the APT plug is missing?

69442C

Looks like a cotter pin shoved in from the other side. Likely a washer or something on the other side to keep the cotter pin from pulling through. I guess that was what someone had laying around at time.

FlyingV5150

Something to add, i checked my ATF and it was really low, like on ADD. I know someone mentioned it could be burning transmission fluid. The smoke doesn't really smell like it but could be a possibility?

Tried playing around with the choke spring, but the thing would not turn enough to close the choke all the way, like something is stopping it. Weird.

I'm sorry but i didnt have a chance to take pictures of the numbers on the carb, i will try and do that tomorrow. Thank you all for your help and suggestions so far, even though its not really fixed yet, i am truly grateful for your patience and understanding.

76olds

Your trans should be fine if it was too low it would slip when you put it in reverse but do top it up it may just be leaking a bit at the speedo cable. Like the guys say its more a choke issue or timing issue, I'm wondering about the heat riser in the exhaust may be sticking, not sure if your car was equipped with one but if it sticks closed may sound like a valve clicking on the passenger side. Maybe others can chime in on this.

oldcutlass

The engine was running when you checked the trans fluid right?

JPMDaddy

don't see the hot air tubes for the choke - but perhaps my 71 has a different set up?

FlyingV5150

Other Eric- Yes, i followed what my owners manual procedure says to check it.

76olds

The dark spot on the intake? Could it be fuel coming out of the accel pump running down the carb? Maybe that may be the hesitation or stumble ? The white smoke.... I had a heat riser stuck shut on my 78 vacuum line rusted out and didn't pull it open then the passenger side head gasket went. What do you guys think?

Octania

Joe, please. It's the factory cotter pin with square nut. And by "factory" I mean those parts were made by a factory, somewhere.

Usually 2 throttle springs are considered sufficient.

The 1980's SOB [Some Other Brand] carb is probably not the best match as far as fittings and ports and throttle cable linkages. Maybe with a little more cobbling...

The choke's black plastic screw slot is broken away per usual, because idiots try to turn it w/o breaking it loose first. Er, so I hear. At least they TRIED to hook up the carb's hot air to the intake's supply of hot air. Not sure that was all that successful.

I am not super familiar with the 80's QJets with the aft secondary pulloff canister but I think there might be a link rod missing from the front pulloff, and its vacuum line appears to be too short and poorly attached.

It would behoove you to take a course on QJets 101
maybe try some youtube videos.

e.g. you say the choke adjuster won't go far enough, it stops. it is possible, I believe, to assemble it wrong, with the spring on the wrong side of the mating tang inside. Then, it works poorly if at all. ANY adjustment of the choke coil should be done with the throttle propped open, to release the fast idle and associated links.

QJets 101 again...

Also relative to an above post, snapping open the throttle briefly after a minute or 2 allows the fast idle to drop down- the choke plate can open faster than that- its motion is controlled by the thermal spring allowing it to open gradually as the engine heat comes up, and the [front] pulloff forcing the choke to open just exactly the right amount [if properly set] immediately after startup.

All of these, and so much more, certainly can be out of whack on any carb. And with the carb/engine mismatch, it may never be possible to get that carb right for that engine.

Then there's the HEI and its advance curve vs. what is best for the engine as it is currently configured.

You would probably be miles ahead to get a proper 70-72 Olds QJet and rebuild it and start from there. I have a pretty shiny all rebuilt one for cheap, BUT... the inlet threads are stripped, so it needs that repair job done.