JpMotorsports

I just did a complete engine detail and replaced top end gaskets, replaced the edelbrock carb with the original rebuilt q-jet. It has a edelbrock performer intake manifold. I replaced the old distributor and coil with a pertronix flame thrower 2 system. I believe I got the vacuum lines hooked up right? But the car will not run right. At idle it runs and seems like it was before the work was done but under load (driving above 35mph) the car bogs and has zero power and get up n go. Tried to retard the timing and it seems to make the car misfire and shift poorly. Tried to advance it and it runs even rougher. Not sure if the distributor is off a gear or two or if my lines are crossed. Took pics but they were not good enough to make sure I had things just right. The car dose not have the old vacuum solenoid. Any tips on what I should do? Tried looking is my service manual for 72 I think the glossary said the vacuum routing was on 6c-11 put my book dose not have this page.




Thanks for any advice/tips,
John

JpMotorsports

it is a 350 with a 4bbl with ac

oldcutlass

How much vacuum is the engine showing and is the gauge steady? Whats the timing set to? Which ignition system is it? Is the pertronix running of the resistance wire?

JpMotorsports

I haven't hooked a gauge to it yet to read. We have been adjusting the distributor by hand little by little and don't know where its at right now on time. Its a Ignitor II with flame thrower coil. Will put the light on tonight

firefrost gold

How much did you play with the q jet ? Was it a known working carb or ??

CutlassDad

You will need a dial back (preferred) timing light to baseline the electrical side of the "tune".




Check your plug wires and routing, paying particular attention to distributor rotation.
I, too have hated those copies of manuals for missing pages.
By vacuum solenoid do you mean the advance canister?

JpMotorsports

Havent played with it since I drove it. During idle we made small turns on the fuel screws. It was a working carb before the PO took it off and put on a edelbrock top end kit (carb, intake, cam lifters)

JpMotorsports

I will recheck the wires. Dosent seem to miss at idle. This is what I meant when I said vacuum solenoid

joe_padavano

That solenoid is part of the transmission controlled spark system.

For diagnosis purposes, simply connect one vacuum line from manifold vacuum directly to the vacuum advance. If you have AT and/or power brakes, connect those vacuum lines also. Disconnect and plug everything else. NOW check for vacuum leaks and test drive the car. If you still get a bad bog, my money is on the secondary air valve spring adjustment.

oldcutlass

Most remove the that and either hook a vacuum line to the distributor advance from a manifold or ported vacuum source. Without real info on what you have your tune specs set to, its hard to point you in the right direction.

JpMotorsports

Thank you guys I will get the specs tonight and try what is suggested at this moment




Thanks,
John

JpMotorsports

So last night we did have some vacuum lines crossed on the carb. Got those figured out and went down the street. On our way to the stop sign the car seemed to run very well. Once we tried the leave the stop sign the car stalled. Tried several times to refire only to have it run extreamly rough. Found the car had ZERO vacuum was able to limp the car home pulled the carb and found a blown (new) carb gasket. Went to the auto parts store and bought another one (the ones we are using are the thicker 1/4" gaskets) put that one on car started up and was running fine until we went to drive it. Made it 5 houses down and the car died out again and barely limped it home.


My question is I am running a edelbrock intake manifold and switched from the edelbrock carbback to the original q-jet. The edelbrock intake has a 2 wide openings the carb mounting area vs the stock manifold had 4 holes for the carb. Do I need to buy any kind of special spacer or insert to run this carb correctly?

gs72

Sounds like it might be starving for fuel under load. Check fuel delivery to the carb and verify proper needle and seat adjustment. And definately dial in your ign. Timing.

oldcutlass

Most of the Edelbrock manifolds will accept both the spreadbore and the squarebore cabs. Which manifold are you running?

JpMotorsports

its a performer not sure the model number its on the box at home

joe_padavano

DING DING DING.

This comes up a lot. The dual-compatible E-brock intakes can have problems sealing properly to the carb. There are 1/4" thick metal spacer plates that seal off the oversized carb holes and help keep the gasket from blowing out.

lemoldsnut

Joe is so right on this. Had similar issues. Get the plate and gaskets then remount the carb. Should fix most issues.

JpMotorsports

THANK YOU Joe!!!!!

JpMotorsports

Do you know the part number needed?

oldcutlass

Edelbrock 2732, I've never needed one, lucky I guess:
http://www.jegs.com/i/Edelbrock/350/2732/10002/-1

don71

I'm confused.

Whey would he need that 1/16''plate? or that skimpy gasket? Wouldn't that plate prohibit secondary throttle plates from opening? And isn't it for square bore carb?

He has a performer intake, With a quadrajet. Thats a spreadbore carb.He needs the thick base plate gasket for a quadrajet, it like a 1/4'' thick and accomadates the spread bore.

Now, if he were using an edelbrock 1406 carb, then yea he might need that plate.

I'm trying to learn here, not confuse the OP.

don71

I think Ken (fun71) just linked the proper gasket the OP needs, in another post.

post #6

https://classicoldsmobile.com/forums...thickness.html

http://www.napaonline.com/Catalog/Ca...335_0147291736

oldcutlass

Sorry that adapter I posted up top is for a squarebore. A thick gasket as Ken stated should suffice also Felpro FPG 60335.

If you want a plate, here is the right one, Edelbrock 2731:
http://www.summitracing.com/parts/edl-2731/overview/

JpMotorsports

A local olds guy got me in touch with a carb guy here in town and I got the thicker 1/4" gasket will try this tonight and hope for the best.

JpMotorsports

Did a lot of work this weekend to the car. Had to make quite a few tweaks and adjustments to the car and choke. Found that the intake gasket was bad a causing a massive vacuum leak. Pull the intake, carb and ect off and got another new FelPro gasket. Compared the 2 gaskets and noticed the grooves around the intake openings were reverse on the old compared to the new. The new one fit a lot better. Got everything put back together. Running at 11 1/2 degrees of timing and made more adjustment to the carb. Now I have to replace the spark plugs they are fouled out. Hopefully the new ones will get the car running just right. I am using AC Delco R45S plugs Test drove it with the bad plugs to see if they would clear but they did not and only could get the car up to 40mph. The car idles very happily.

coppercutlass

fwiw some on the bolt holes on the edlebrock manifolds dont have a bottom meaning they go straight into the intake plenum. I drove around for a year with a vaccum leak to no ill effect amazingly. i eneded up putting a set screw with rtv to block it off.

BangScreech4-4-2

In reading this entire thread, I notice that you went from the E-brock carb on the Performer manifold to the Q-Jet on the same manifold. Why did you do this, and did you ever consider going back to the E-brock carb?

JpMotorsports

Looked up info on carbs and talked to a few Olds engine builders and they said the Q-jet was a better carb for my set up. Was not too happy with the performance of the edelbrock. Plus I am going with a more stock looking set up but did not put on the original manifold just for a little performance

BangScreech4-4-2

Did it run okay with the Edelbrock?

JpMotorsports

The edelbrock ran really rich. Pulled the dist cap found out I was 180 degrees off on timing. Got that reset and the car runs and drives really well. Needs some final tuning and then its time to enjoy the car.

oldcutlass

Are you saying that the distributor being 180 out was the cause of your car running(?) poorly as described in this thread, and correcting that cured the issue?

JpMotorsports

It was a mixture of being 180 off a bad intake gasket and some internal parts in the rebuilt carb.

Gre975

Could you explain this further? I'm in the process of diagnosing a possible vacuum leak and will look into this as a possible cause. Thanks in advance.

oldcutlass

If you spray carb cleaner around the outside of the intake and around the base of the car, with vacuum leak the engine will suddenly smooth out and the idle will go up if the spray gets sucked into the leak. I use plumbers pipe dope on the threaded ends of the manifold and water neck bolts.

coppercutlass

The Inake has bolt holes for a qjet and the standard holley flange. Some of the bolt holes have no bottom meaning they go all the way into the intake. If left un plugged you have a vaccum leak. I drove mine like that for a year. Somehow still had power brakes but it went from an erratic idle to nice and smooth. I though it was the cam it had.