Finn5033

Hello, I am new olds owner and new to the site. I introduced myself on the newbie forum already. I bought a 1970 Cutlass Supreme converitible with a 350. It is not the original motor it is out of a 442 I don't know what year. He also gave me the original numbers matching 350, the timing chain had broke on that one. Until a couple weeks ago the car had been in storage for 5 years. The guy I bought it from got it out and made sure it was running well enough for me to drive it home which was a 2 hour drive. The car starts well and idles pretty smooth, but it has no power. When I was driving it home on the highway it could not go up a hill without losing speed. I would give it more gas but it would just down shift rev up and shift back to 3rd. It runs well enough to take out for some back road cruising but that is not good enough for me. I am not a speed freak but I would like the car to be able to break the tires loose like it should. I know there are a lot of things it could be. And possibly being just an old tired engine is one of them. Last weekend I changed the oil, the plugs, the wires look brand new so I left them. This coming weekend I plan on changing the fuel filter, points cap and rotor, and was thinking about rebuilding the carburetor. Or at least cleaning it, but I figure if I am going to take it apart I may as well rebuild it? Any thoughts or advice would be greatly appreciated. I have some other questions but would like to start with getting this baby running up to par. The car does have the original tranny and rear end still.

RetroRanger

if it runs good and lacks power I would check the distributor vacuum and mechanical advances to be sure they are free and operating correctly

Finn5033

Ok will do. Do you think the carb is the last thing I should mess with?

455man

I'd do the carb last. Plugs, wires, points, cap and rotor. Maybe the carb needs air/fuel adjustment. Make sure the timing is set right and the vacuum advance is working (mine was not when I got my car). Do the basic tune up then we can start playing to get you more power. My stock 350 2bbl car has about the same hp as my 04 v6 Monte Carlo but the torque from the 350 is noticeably more.

Finn5033

Sounds good. I will check all of those things this weekend and see what happens. Could you go into more detail on the vacuum and advance and how I would check that?

455man

With the car idling pull the vacuum advance off the manifold or carb where ever it's hooked up. If it's on the manifold the idle should drop when you take it off. If on the carb it probably wont affect the idle. If it's on the carb hook it up to manifold vacuum. if it idles up then its working, if not then you might try sucking on the vacuum line to see if the idle increases or if the line holds a vacuum. There are other threads on here explaining this and they might explain it better than me.

brown7373

How old is the gas in the tank?

I remember driving my 69 GTO back in 1973, and it started having similar symptoms. I was on the PA Turnpike going up a mountain into Somerset, and it hardly could stay above 40 mph. I limped into Somerset, and broke down. After a couple repairs that got it running but not fixed, I made it back to Philadelphia, where I continued to have the same lack of power. Long story short, the problem was the primary wire from the points to the negative on the coil had gotten pinched and cut almost in two. It was held together by the insulation on one side, and it either had limited power, or when the wire strands lost contact from vibration or a bump it would totally cut off. Back then, I bought a new wire for 80 cents and it fixed the problem.

Check all the electrical parts and wires closely.

Finn5033

The car actually ran out of gas when I test drove it. I filled it with new gas, put a can of seafoam in as well, but I have not ran that whole tank through yet. I also sprayed some carb and choke cleaner in the carb while it was running. As I said in my original post the engine seems to run nice, its just when you step on it there is no response.

J-(Chicago)

If it is a 4 barrel, are all 4 barrels opening?

With the car off, hold the throttle all the way down and look down into it with a flashlight to make sure the front 2 and the back 2 are opening.

There are a series of levers on the passenger side by the choke, that you may have to shimmy with as well in order to "unhook" the back 2 and allow them to open.

Play with it a little and see what you find.

Finn5033

It is a 4 barrel. I want to say thanks to all you guys for the good tips. I will check out all of these things this weekend and update on my progress

jag1886

I'd also be checking the timing chain, a stretchered chain and worn out top gear will make it have no power.

RetroRanger

for this discussion theres two types of distributor advance, vacuum and mechancal.

the vacuum advance changes w engine load, less load more advance

if you unplug the vac advance line (at the carb or manifold) not at the dist and pull a vacuum on it the idle should increase, if it doesnt find out why (bad vac canister on the dist or frozen mechanism in the dist under the cap.

the mechanical advance is actuated by RPMs more RPMs more advance. if you set your timing ( 8-12° BTDC assuming points) (w vac advance line disconnected and plugged) and then run the RPMS up to say 3k you will see the timing mark 'walk' away as RPM increases and then return as RPMs come down. if it doesnt check for a stuck mech advance mechanism under the dist cap (weights and springs) (different than the vac mech).

thats the simple explanantion if they both move good...later you can investigate how much they move and when which will alllow you to get everything you can from your engine.

oldcutlass

Since the car has been sitting for 5 years...

After you run the seafoam through your system, I would replace the following, points, condenser, cap, rotor, plugs, wires, air filter & small breather in the housing if equipped, and the PCV valve. I would also change my fuel filter. If you are running a quadrajet, the filter is located in the carburetor inlet. there may also be an inline filter installed by a previous owner.

Check all the vacuum lines for cracks and insure they are hooked up correctly.

I would also check all the fluids, transmission, radiator, brake, and replace oil and filter.

Gap plugs at .030, set dwell at 30*(no more, no less), set timing at 12-15* BTDC at 800 RPM, which should equate to 35* at 4000 RPM with vacuum advance disconnected. Reconnect vacuum advance. Then set your carb air/ fuel mixture as mentioned above for highest vacuum or RPM. Set your idle speed to 850 RPM in Drive.

Take for a good drive, if you sense any pinging or surge, decline timing in small amounts until it goes away.

Finn5033

I have done a few of those things but do intend to do most all of them this weekend. As for setting the timing that is way over my head. Does anyone know of a good video I could find that would show me how to do that?

Finn5033

@J-Chicago I tried what you said and checked to see if all the barrels were opening when pushing down the throttle. I attached a picture of the carb while I was holding the throttle wide open. It appears to me that the front is opening but the back is not. Please let me know what you think

oldcutlass

I think the choke plate is blocking your view of the throttle plates on the bottom. Was the engine completely warmed up when you took this pic? The secondary linkage (the back ones) on the 4 barrel needs engine vacuum to open. Sometimes you cannot accomplish this just rev'ing the engine when the car is not moving, it needs a load.

Finn5033

Ok, I was trying what J-chicago recommended. I may have misunderstood what he meant. He said to try that with the car not running and looking at the carb. I did not know that the choke plate covers the barrels. I will try again

oldcutlass

No problem, we all have to learn sometime. You can manually prop open that plate with a screwdriver, and then do what j-chicago suggested.

455man

That's another thing he can check. Make sure the choke plate (the small one) is open all the way when the car is warmed up. It's an easy adjustment if not.

Lady72nRob71

I had this issue before i found the bushing on the throttle cable to be missing. She was still not sluggish though under normal driving, but adding the bushing really helped WOT response. It was nice to hear her howl afterwards!

louie

When the pedal is mashed are you sure the carb is coming all the way full throttle? Doesn't hurt to check.

Lady72nRob71

Excellent point - mash the pedal, rather than opening the carb by hand. This is how I found my problem. I now recall I also had to add a sleeve to the throttle cable up above the pedal so it would have more "pull".

bigD

it sounds to me like your timing is retarded or you have a fuel delivery issue. vacuum advance is more about mpg than performance so other than making sure it's not the source of a vacuum leak i'd focus elsewhere for now... my gut tells me that the base timing is way too conservative.

is it a points or hei distributor? the previously mentioned 10-14 degrees of base timing is perfect for points but hei needs 20. if the previous owner installed an engine with hei and set the timing to the tag on the radiator support it will definately be a dog... that is where i'd start. first determine if you have a points system or hei, points will have a seperate coil whereas the hei is all one unit and is a larger diameter then either find a buddy that knows how to check timing or run it by a shop and have someone check it. remember 10 to 14 btdc for points & 20 btdc for hei.

Finn5033

@bigD, thanks for the tips. I am bringing the car by a friends this weekend to check the timing and the dwell. I believe it has points but we will find that out. And thanks for the numbers on the timing. This car is way too sweet to be a dog, one way or another I am going to get her rippin' before the weekend is done. (hopefully)

Finn5033

Well I brought the car to my friends today and found it does have an HEI system not points. Unfortunatley he also said that the blow by was pretty bad and that the oil rings were probablly worn out because there is a lot of oil coming out. We checked the timing anyways it was set at 6. We timed it up to 20 and after it was running for a few minutes it started knocking really loud. Sounded like it was starving for oil. We pegged it to the drivers side of the motor. We decided to pull the valve cover to see if there was any oil coming through. Well after that my friend said it was clear that this motor is on its last leg. He has a lot of experience with motors and he said it was the filthiest he has ever seen. That being said I am going to be looking for a new motor. Thanks for the help everyone

bigD

that sucks! it shouldn't be too hard to find a good 350 olds to put in it. you may want to consider freshening that engine and reusing it. the worst thing about buying a used engine is not knowing it's history...