84oldsDelta88

So I just finished the swap in the delta thanks to everyone for all the help along the way. When i took it for a test drive i noticed the engine bogs down when i attempt to gun it as if its running to lean. Its running a 1970 350 2bbl from a cutlass, I used the intake, carb, dist., and all the accessories from the 307 so it has the 4bbl quadrajet carb on it now. Do i have to richen up the mixture or install larger secondary metering rods? Adjust the m/c solenoid maybe? Or could it be my timing is off a couple degrees? I'm sure someone has done this swap the way I did hope someone can give me an idea of what I can do to fix this.

70Wcars

First try tightening the Secondary Air Valve Spring. Located on the Pass side of the Air Horn near the linkage of the Secondaries...you can google this or refer to some of the Q-jet books for a detailed explanation and pics.

Second, if you do need to richen the Secondary metering, you will want SMALLER metering Rods, not larger. They restrict the Fuel Flow until raised up out of the orifices, so smaller dia. tips will allow more fuel to flow.

Hope this helps and good luck with your project.

Danny

1965cutlassragtop

get rid of that quadra-bog....that's your problem right there:-) they didn't get that nickname for nothing!! you can tweak it and get okay results, but it will just need tweaking again in the near future. get a holley or an edelbrock....then you can "set it, and forget it"!!!

jag1886

I would have to guess it's not to rich but you are trying to shove to much air down it to fast that's usually what causes a bog. Did you replace the timing chain or anything on that 94,000 mile engine before installing it??

84oldsDelta88

Ok will give it a try and see what happens thanks. is it possible to maybe grind the metering rods a little smaller?

I have to run the emissions equipment cause i live in jersey which does emissions testing every 2 years otherwise i would of.

Yes brand new timing chain, and new oil pump and gaskets is pretty much all I've done to the motor, could the transmission possibly cause this? Cause i notice when i free rev in park or neutral it runs great but in gear it bogs and hesitates a lot, and when The secondaries open up it really bogs down,


thanks for the help everyone i will try what you guys said and see what happens, i adjusted the dist. timing a bit and it idles smoother now so its getting there

MDchanic

Oh my God, no.

And, just to clarify, it is "bogging," and not "flattening out," right?
In other words, it accelerates, hits a certain point, then slows down -
it doesn't accelerate, hit a certain point, then just stop going faster?

Also, does NJ run it on rollers to test the emissions, or do they just put the sensor in the pipe? You might be able to get away with almost all 1970 parts (along with the original catalytic) if you tune it well, so long as it doesn't have to be tested at 60 mph.

- Eric

Redog

Is this car a daily?

If not put QQ plates on it and rip out all that emissions crap

MDchanic

What he said.

70Wcars

The symptoms really sound like a slight Lean spot from the secondaries opening a bit too fast...I would tighten the secondary air-valve 1/4 turn at a time, then test the results, and tighten again if needed.

This is a mechanical adjustment and is locked down with an Allen head set-screw, you shouldn't need to " tweak " anything once the set-up runs right for your application. Just keep in mind the early model engine being fed by a late Carb with calibration more suited for emissions than performance.

There are SS cars in NHRA and IHRA running in the 9's with Quadrajets...in my opinion these carbs much maligned reputation comes from myths most likely started by tuners of questionable ability and patience.

Again just my own thoughts.

Danny

olds 307 and 403

Your joking right? The newer Holley's might be better but the old ones needed constant fiddling. My Qjet needed no adjustment other than a tightened secondary air door.

redoldsman

I bet there are more member cars on this board running quadrajets than any other carb. I had a 79 Caddy once that did the same thing. It like to have driven me crazy. If I remember correctly, there was an adjustment on the air door over the secondaries that needed adjusting. That was long ago and there was no internet then. It was a simple adjustment.

ah64pilot

The first 455 I ever played with did the same thing to me...Revved just fine but when I stomped on it in gear it just flattened out and then overheated and then it left me on the side of the road, all in the same day. I learned a valuable lesson that day.

There is a reason a decent looking '70 Cutlass SX would sit in a driveway for 10 years...it had a cracked block.

At least the whole car only cost $500 and other than putting a Performer carb on it I hadn't done anything to the engine. Ahh, the good ol days...ignorance is bliss, until you lose a highway race to a 1/2 ton Chevy full of mex...guys.

84oldsDelta88

I guess it would be bogging down, i accelerate and when i go to wot the motor slows down like its starved for fuel until i let up on the pedal

and in NJ they just stick the probe in the tailpipe.

it's mostlikely gonna be my daily driver, only cause my insurance company will not insure me for a classic car they said they dont offer classic insurance. and i've tried a lot of other companys that give me the same thing.

hmmm. when i get home later tonight i'll have to give that a try and see what happens thanks for the advice

scubastever

agreed- you might be able to set and forget the Edelbrock, but the Holley will need more attention than a jealous girlfriend.

1965cutlassragtop

i was battling quadrajet issues years ago....i threw on the edelbrock power package and left those worries behind. the only thing i've had to adjust on my edelbrock carb is the idle.

my point in the earlier post is that people continue fiddling with and adjusting these quadra-bogs and they can never get it just right, or it's good for a week or two, then start acting up again. save your sanity and just buy a newer, better operating, better performing carb. one of the best purchases i made for my engine.