I think I need a new or rebuilt carb in my 1984 307Y Delta 88 Royale. It has 190,000K miles and to my knowledge, the current carb is factory. I've had it for 100,000 miles without a change. In the mornings, warm or cold, it starts wonderfully but quite a bit of smoke does come from the tailpipe. I'll pull out of the drive and if I can go fast, say over 45 MPH, then its okay until I come to the stop sign about 3 miles down the road. When I accelerate, it will either stall, particularly when its raining, or once I hit the pedal it will pop and hesitate and blow black smoke out of the exhaust, but as long as I DO NOT let off the gas, it will be fine in about three hundred yards or so and then fine for the rest of the day, or until it totally cools down and have to start the whole process over. Also, when sitting idle at a traffic light, the smell of gasoline from the exhaust is great in volume. But it runs fine other than that. Pickup is still good (this is my second 1984 and I've owned a 1983 and 1985 also) but this one has the worst gas mileage, running about 12MPG in the summer and about 8MPG in the winter. I've replaced the sparks and all other basic stuff and am thinking this Quadra-Jet needs rebuilt or replaced. Anyone else had this problem? I'd get rid of it if I could buy a new Olds but. . .can't think about it right now as my blood pressure still skyrockets when I think that Buick and Pontiac are still in production!!!!! Thanks in advance for anyone who can point me in any direction.

Nick

Hi yaekle, hello everyone,


OK. Now that you have everyone focused on your carb, I think I'll ignore it, and see where your symptoms lead.

How long has it been since the problem started? Was anything changed or "adjusted" at about that time?


Did you gap the plugs? What basic stuff? Air/fuel filter? Vacuum hoses and/or pots? Did you check the distributor advance for proper operation? Cap, Rotor, and wires check out OK?


I haven’t seen any reason to blame the carb. Why do you?

While we wait for your reply, I’ll see what I can make of the rest of your info.

Regards, Norm

OK. I thought it was the carb because a mechanic I know said that's what it sounds like to him, as he apparently knows the Quadra-Jet.

I have regularly replaced the spark plugs, and yes they're gapped correctly; air, oil, fuel, PCV valve, hoses, belts all changed; No changes except the idler screw (I think that's what it is- screw and a little arm with a spring that makes it idle faster or slower-it's set where it needs to be so that it will stay running and doesn't constantly blow black smoke). The timing is correct and distributor cap was changed by a mechanic about a year ago. The car has been doing this for about two years. Also, it seems to be going through too many exhaust parts- catalytic converters-2 in three years; two mufflers in three years; tailpipe fell off after one year-corroded and rusted. I'd just take it to a mechanic but the ones I knew that I would trust have moved on and these other places can't seem to do much more than an oil change.

Thanks again. Sorry if I didn't answer all your questions but I'm new to these threads and forums and can't figure out hwo you quoted text!

Nick

I was thinking that it could be a timing chain problem, but I think that would be a consistant thing. Although, if it slipped one tooth, that could maybe cause some weird problems.

Since is is spitting and sputtering, the first thing that I would do is replace the fuel filter. I think that one may be in the carb inlet. In the process, I would do a fuel pump volume check, to make sure your fuel pump is operating.

I dont really think its a fuel problem as the symptoms of that are more of lack of power when you hit the throttle.

You are definately running rich. But that may be for a variety of different reasons.

Did you change your plug wires when you did the plugs? Did the mechanic change the rotor when he did the cap? How long ago did you replace the pcv valve?

Andrew

I forgot one important item. The car DOES NOT sputter ONLY if I put Sunoco Ultra 94. If I put Shell 93 or Generic anything octance rating it will sputter. But when I run Sunoco Ultra 94 regularly, while it still smokes white at start and black on acceleration, it doesn't sputter. Also, my stepfather noticed a strong gasoline smell in the motor oil even right after an oil change.

The PCV waschanged less than one year ago, about 10,000 miles ago. I did not change the plug wires as they had been changed about 20,000 miles ago.

Thanks guys for all the help.

Nick

Everyone:
Please note the difference between “checking/testing” and “replacement”.


White smoke? What other times do you see white smoke?


Do you head out or back out. If you back out, what happens when you stop, then move forward? What is the time lapse from the start, to this point?


Discribe OK vs the way it is supposed to run.


Two different results under the same conditions?


In this case, does "on the gas" mean acceleration, or cruise?


Everthing works exactly like it should? No black smoke?


Anyone, who knows carbs, would able to tell you which part is causing the problem, and why. If he only knows how to rebuild them, it would explain his diagnosis.


Base timing should be 20°.


That would be the Idle speed adjustmment. That was done 2 yrs ago?


Warm idle should be 600 RPM, in gear.


And it had no problems before that?


No help. The cause, is the problem we are working on.


Look for a Mom & Pop shop where the owner, or at least one mechanic has, a minimum of, 20 years of tuneup experience. A GM dealer might be a good choice until then.


You are trying to tell me everything my own five senses would tell me, if I was there. Do not apologize, just do the best you can.


In my case, your answers are far more useful than any quotes.



There is some evidence of a cam timing problem, but nothing I would bring up, yet. If I thought he was handy enough to check it himself, I would have.

The subject does deserve discussion, but I’m concerned about the integrity of the thread.


I would check it, and replace it, if necessary. If he is is paying for the labor, I would not suggest it.


Unless another has been added, that would be it.

Regarding the filter vs a new or rebuilt carb: If the filter was the problem, a new one would be in both, and the owner could pay $500.00 for the needed 98¢ part, and never know the difference.


Good idea, if, he’s not paying someone to do the labor.



Useful, it eliminates several possibilities.


That's consistent with the black smoke.


Doesn’t mean they are still good. They are on the maintenance schedule and should always be checked at those times.

Should have asked in my first reply. How much of this can you do yourself?

Norm