Rustbucket2

I rebuilt a 74 Olds 350, I'm using the factory heads and intake, and the factory Quadrajet. I installed a Elgin E-976-P Cam, specs. 204/214@050 , .449/.473 , 112 LC. I can't get this thing dialed in, The carb has been rebuilt 3 times, by two different people, in park it sounds like it has all kinds of power, the 4 barrel opens up, but, put it in gear, and it has little power. like it's running lean. It will not restart if choke is open, even after it warms up. Do I need a bigger carb? do I need a different intake? I don't want to throw money away, so what do you out there think, where should I start.

oldcutlass

What ignition system and what are the settings? Was the cam installed straight up?

Rustbucket2

Sorry , if I come off lost, I'm a stock guy, built this car for my brother , he wanted a rv cam, as he calls it. cam was installed straight up, he did replace the dist. with a HEI out of a 79 olds 350.

BangScreech4-4-2

Not that this is responsible for your problem, at least not entirely, but I notice your cam is very mild on the intake side. This could be a contributing factor if your timing is out of whack.

Rustbucket2

I tried setting timing @ 12 but it sounds better @ 8

oldcutlass

I'm assuming that the HEI has full battery voltage hooked up. Most HEI's have around 18 degrees of mechanical advance, try setting yours to 16-18 and adjust your idle down to 700. Adjust your carb so that both a/f mixture screws are the same turns out and for the highest vacuum on a gauge. Also note that the vacuum gauge needle is steady.

joe_padavano

If you are seeing the secondary air valves on the Qjet open up when you rev the engine in PARK, the air valve spring wrap is NOT set correctly, which will cause the air valves to open waaaaay too soon and cause the engine to bog dramatically under load.

cutlassefi

Not sure if I've ever seen the term "straight up" misused more in one post.
Unless you checked the cam timing there's no way you can know if it's "straight up" or not. Eric ( Oldscutlass ) what does "straight up" mean in your mind?

You may have a vacuum leak. Double check plug wires, centrifugall advance etc.? Or if you used a cheap timing set the cam timing could be off enough to cause a problem. That's a slow lazy cam anyway. Unless you have 9.0:1 or so that may not have been the best choice.

oldcutlass

It means the same in your mind Mark, lining up the timing marks vs advanced.

svnt442

Olds HEI distributors have A LOT less mechanical advance built into them than the old points distributors did. With a points you can st the initial at 8° and be fine, where an HEI will require between 16° and 22° of initial for it to run correctly.

cutlassefi

Ooooh that's where you're way wrong, not even close.
For the record straight up means;
If the cam was ground on a 112 lsa, then "straight up" means it's installed on a 112icl. If its ground on a 110lsa then "straight up" means it's installed on a 110icl.
Lsa is ground into the cam, icl is adjustable via a multi keyway timing set etc.
Too many people think like you do, even established shops. Lining up the dots means absolutely nothing. It could still be way off doing it that way, there are no guarantees it'll be correct.

wr1970

Hmm food for thought!

oldcutlass

Thanks for reiterating the pitfalls of cam installs and if you want to be sure a degree wheel is your friend. In most cases when people install mild cams, they line up the dots. 99% of the time its correct. However I've found people have lined up the wrong marks and the engine runs like crap.

Rustbucket2

I had a Oldsmobile person stop and look at carb, still not running right. here is what he found , vacuum is holding at 18, no bounce in needle. vacuum advance was plugged into a full vacuum port, 2 vacuum hoses were too large for port, they where plugged into, and the part on back passengers side of the carb, that opens the secondary's ( no I don't know the name of it ) , will not hold vacuum . Other things , the timing mark tabs are for points, and only goes to 18 so I changed it to a HEI timing mark, it goes up to 24. I think my plugs may be wrong now, what should I be using with HEI? right now I have R455, gapped at 35, should I be running R46, gapped at 60? Thanks for the help, some day I will get this stuff right.

svnt442

No matter what they say for gap I have found that .045 has always worked well for me with electronic ignition with a standard reach plug. My 76 and 80 were speced at .080 and IMHO that stresses the coil too much and really does nothing for the flame front.

Have you adjusted the timing? And if so how has that effected how it's running?

Rustbucket2

anything above 18, it sound good and turns the tires easy, but after it runs for more then 5 min, it has no power, like something has shut down, if you want to restart it, you have to hold your foot to floor, to get it started ! after you get it started it will not stay running, unless you hold the pedal down with your foot. After it cools down ( the next day ) one pump on the pedal and it starts right up, but after it warms up, your back to step one.

coppercutlass

Choke issue ????

1BOSS83

AC delco r43 @.040
I dont think I saw Joe's response acknowledged, pardon if it was but are the secondaries opening in park?

1BOSS83

After it is to temp does it bog heavy or stall or just under perform?
When you say foot to floor- are you pumping or just burying your foot in the throttle?

What do the plugs look like AFTER the car comes to temp and requires all the fanfare to restart?

olds 307 and 403

Are you talking there rear pull off, brass in color with a curved nipple? That pull off can be eliminated or has to be replaced or you will have a vacuum leak. I have run the Eldelbrock and Melling version of that cam in low compression 350's and 403's. They like a lot of part throttle timing, make sure your vacuum advance is functioning. That cam doesn't build a lot of cylinder pressure but if that one is 112 LSA vs 114 LSA, which most of the versions are, it will help. It sounds like a carb issue, your stock carb will be close to the right jetting, IF rebuilt properly, sounds like it isn't. Was the float replaced? What brand timing set was used? If you didn't mill the heads or block and reused factory pistons with Felpro head gaskets, you will have 7.6 to 1 for a compression ratio, even worse than the original 7.8-7.9 to 1 factory compression. Add in a bigger cam, that will even drop cranking compression even more. Check the plugs, the hotter R46 will be better and gap at .045" and do a compression test.

Rustbucket2

It will stall , in park @ idle. paddle all the way to floor, then it will start back up. I have added a pic of the part that will not hold vacuum , I was told this opens the secondary's. The secondary's worked one time, but don't open now! sorry for the bad pic.

joe_padavano

Whoever is telling you this is incorrect. The rear diaphragm on the passenger side of the carb is the choke pull-off and has nothing to do with the secondaries. The front diaphragm is the one that controls opening of the secondary air valves. It does NOT "open" them, it holds them closed under high vacuum conditions like part throttle when you don't want them fully open.

And once again, the plates you see on top of the carb are NOT the "secondaries". The secondary throttle plates are on the bottom of the carb and are mechanically actuated with the throttle. The plates on top are the secondary air valves and those are only supposed to open under load. They are normally NOT supposed to open when you are revving the engine in PARK.

I suggest that either you become more informed on how a Qjet works or find a "mechanic" who has a clue. Otherwise, you will be spending lots of time and money on things that are not related to your problem and will likely make it worse.

Octania

A good repair strategy is

1) find out how things are supposed to work- what each part or system does and how it accomplishes that.

2) find out which part or system is not performing properly

3) remove, renew, modify, or otherwise cause the inoperable part or system to behave in such a manner that your machine works better.

You have not even gotten to Part 1 yet. Nor have the carb guys. What is the point of attempting to make a carb work correctly using vacuum actuators that do not hold vacuum [therefore cannot work right]?

Many folks have read the two most common carburetor books to gain an understanding of what all them little pieces and systems are called, what they should do, and how to tell if they are not doing it right. You can too. I know a carb has what appears to be an infinite number of little bits and parts and adjustments, but the number is actually finite, and you CAN master each and every one... it just takes a while.

Sounds to me like your float level is incorrect and/or dirt is causing low flow. Filter in backwards maybe, etc.

Rustbucket2

That's what I thought I was doing , is ruling out things as I went, by the help of the fine people on here. Filter can only go in one way ( on quadrajet ) I have all kinds of time, and I know I could learn all about carbs and how they work. That's how I learned to weld new quarters and floors in cars, and how to do body work, and put a hell of a paint job on a car. My brother tough , not very patient , would like to take his car to car show on the 12th of this month, I have a friend who drags his cutlass at Muncie , he is going to loan his carb ( Predator ) to me, so I can rule the carb out, or blame it all on the carb. I'm 99% sure it's the carb.

Rustbucket2

The plugs are black , no gas on them, and not wet, I pulled #1 plug wire off, when it was running, it made no differents in the running of the motor!

oldcutlass

So if you stuff a screwdriver in the end of the wire for #1, hold it next to the block, and crank the engine while its hot, you get no spark?

Rustbucket2

I get spark , and it's yellow, this will drive me crazy, can't wait to try a different carb and different plugs.

oldcutlass

Unplug the distributor 2 wire plug on the outside of the cap, and connect a 10-12 gauge wire from your battery to the Batt+ terminal on the distributor. Start the car with the key and see how it runs. Note in order to turn it back off the jumper will need to be disconnected from the battery.

1BOSS83

are you testing the coil or electrical supply to the coil or...both?

On a related note: the OP stated the HEI is from a 79 olds- Please correct me if I am wrong but: failing rotor, weak coil would cause the low RPM stall and poor spark would cause the loss in power and motor's desire to "want" less initial timing.

oldcutlass

I'm isolating the power supply from the distributor. If he has good spark and it runs great then its not in the distributor its a power supply problem to the distributor. If it still has a weak spark and runs like crap, I'd look at the distributor. Adam you are correct it can be any number of things.

Note, I'm not ruling out the carb either, but we have to start somewhere based on the symptoms.

Rustbucket2

changed the choke that opens secondary's now the secondary's open all the time. Changed the dist cap, and rotor, and went from R455 plugs with 35 gap to R46SZ plugs with 80 gap. Car starts right up, no stall when put into gear, will spin tires, but still when driving down road lacks that get up and go. I know 1BOSS83 recommended R43 with 40 gap, will this plug help?

olds 307 and 403

No, those plugs are too cold for your motor. Make sure there is 12 volts to that distributor, that could be your problem.

Ed Carpenter

Possible lifter pump up preventing valve closure could also result in the #1 cyl. Not showing a difference when the plug wire is pulled, or mechanical timing.

Octania

"changed the choke that opens secondary's now the secondary's open all the time. "

That doesn't sound right. In any way.

Perhaps your trans is not kicking into second from 3rd when you ask for all she's got, and so it lacks the "get up and go" factor?

You can try manually selecting "S" or second gear and see if that does what you want. Various spark plugs and gaps should not make much of a difference.

oldolds88

by any chance are you using the original resistor wire from the non hei for a hot lead on the dist?

1BOSS83

What kind of "get up and go" are you looking for- larger cam on a 74 350 w/#8 heads and stock intake will spin some tires but I don't think you'll be blown away by the mid rpm pulling power.

Rustbucket2

we hooked a hot wire from battery to dist, just like oldcutlass said to try. But that was before we changed plugs. I will try the hot wire again. I will work on it Saturday. Thanks for all the in put .

Rustbucket2

now that you have me thinking, I do not remember the trans shifting , I just took it down the road and back. 3 blocks.

markmag

hi, i'd try checking the valve clearances?,adjustments/lash?...just sayin..mark

BangScreech4-4-2

So what happened?