Hi my 350 is not running correctly. I've changed the plugs wires coil and condenser. The motor idles fine but when you put in gear it starts to jumping not badly but not normal. I was thinking it was fuel filter so I changed that and line same problem. Does anyone think it's the carb I drove it down the road it's picking up speed with alot of bogging in it sounds horrible. The carb is and edelbrock
Junk inside a carburetor can make it jumpy and run poorly. Also check for vacuum leaks. Did you set your timing properly? Have you tried adjusting the ebrock carb?
Remove the carb and bolt on a Q jet from Everyday Performance (here in the vendors section) or from Carmantx. Every week or two someone comes on here with a poorly running Edelbrock carb on a Buick 350... You can buy a re-jetting kit and an air fuel meter and use trial and error to re calibrate the carb or you can bolt on a rebuilt Q jet and move on.... Also get a timing light and set the total timing for 32-34 degrees with the vacuum advance plugged and then re-connect the vac. advance after you are done setting the timing. Use a dial back timing light to set the total timing....
Send the Q jet to Mark, he can rebuild it properly and it will perform WAY better than the Edelbrock ever will... We see this all the time... Edelbrock carb on 350 = poor performance...
How old is the carb, how long has it been running this way. If you have a pretty much stock engine without any issues there is no reason to condemn your Brock. I know everybody says there not the best choice for a Buick and if you use one your leaving power on the table but these carbs out of the box with a few adjustments work just fine. If you have drivability issues I would start with putting a vacuum gauge on it and DIA the problem before throwing parts at. Don't just take a $300 carb off and put another $300-400 Q-Jet in it's place with out at least checking a few things like vacuum, timing, compression.... In the end you might still need a carb but I wouldn't make a $300 + guess EDIT: Just to be clear I'm not saying the brock is better than the Q-Jet, I don't want to open that can of worms there is about 10 pages of debate on it. But on a stock engine (AMC 304, straight 6 Chevy, Ford, ....) and so on. There is no reason it should not work on a Buick 350 even with it's long stroke. After all it is just a big 8 cyl. cast iron AIR PUMP
I agree with smar in that last post, don't just throw parts at it on assumptions. It may be a miss you are feeling. Try this: crank engine up cold, feel of all exhaust ports on manifold next to head and see if any are slow to warm up and stay cold. Infrared temp gun works well for this also. On cold start, all should warm up evenly. A vacuum leak on one runner can kill that cylinder. Put a vacuum guage on it and check for low or pulsing readings. Check compression on all if you find a cool one or miss-fire. How long has it done this and what is history.?
You said you changed plugs, wires, coil, condenser. What about cap, rotor, points (if applicable) my 68 fired up great, idled great, ran great at part throttle, but if I gave it anymore than half it ran like crap! Sputtered choked fell flat etc. Turned out to be bad points. Simple, cheap, and made a world of difference.
If you have a stock intake with the e-brock carb, then you have to run an adapter on it and that makes it run like crap. get the Q-jet rebuilt by one of the guys here and it will be money well spent. The e-brock carb probably needs a new pump diaphragm and that is why you have a bog problem. If it is on a stock intake forget it and take it off, if it is on a TA intake then you have a better chance and there all you have to do is rebuild that carb then it will work.
Can anybody show a chassis Dyno. and or a 2-4 gas reading in which a 1/2" piece of alum or phenolic carb adapter (spread bore intake to square bore carb caused drivability issues. Lean skip at X RPM, off idle stumble, Fat/Rich condition at said RPM (Not lack or gain in performance) on a stock or close to stock engine. All of a sudden carb adapters are **** on Buicks but work well on other engines I love Buick's But it is just a big air pump no different from a Cadillac, Ford or Amc.... Now if there was proof that Brock carbs were being sold broken or with missing parts then ya I would say stay away but for 20 plus years only when installed on a Buick that there is problems and it is some how not combatable I don't think so. With anything there are defects, misprints, ..... If the Buick 350 is so sensitive to changes in intake design (ever so slight change) then never ever swap from a 2GC to a Q-Jet 4V and forget about single plane intakes and TBI, EFI, MPI, and what ever you do don't use forced induction or NOS. Actually don't change anything only run Q-Jets and all of T/A performances products it seems to be the only way a Buick will run Just kidding its Sat night.
Only thing left is the points cap and rotar. A friend came by today and checked it out and said that ....that stuff looks fine so I'm wondering WTF EXCUSE ME but it started acting like this I was installing a thermal limiter to the ac compressor and I rev the gas at the carb at it started this. I turned the car off and fired it up again and it was running regular I plugged everything back up and it started this again seems like it getting an electric shock from somewhere or something I don't know but it has acted this way before with me dealing with the ac just on its on then it comes out of it...If you have a buick you know the sound after it warms up the sound it makes a calm sound when its ready like a smooth sound not to be tipping...it's not leveling out its bogging I miss my baby
Yeah I did this with a bone stock 350 with a stock intake that had a Q-Jet on it and I changed it to an open spacer with a Carter AFB on it which is basically the same as the E-Brock. I ran it back and forth to work for 2 weeks and it ran like crap at part throttle going down the highway. I bought a complete jet kit for the carb and rods to make changes. I tried different rods and jets and the car would not run right at part throttle. On the floor it ran great no problem there but at that part throttle to idle it just would not run smooth. I took the damn carb back off rebuilt the Q-Jet and never had another problem with part throttle. I did this with 2 different motors and I did this the first time back in the 80's and on the other stock engine in 2004, so I know what I am talking about when I say "DO NOT use open spacer with a stock intake with a square bore carb, it just wont work Period". If anyone wants to use a square bore carb then go out and get the TA intake and you wont have a problem. No good for stock intake. The only way it might work is if you get the 4 hole spacer that is for the square bore to spread bore intake but the back two barrels on the adapter are on an angle so I do not know how it would work. My chassis dyno is my butt. My sniffer is looking at plugs.
Yes he should troubleshoot the engine before replacing parts i agree... That being said he will end up fighting with the carb until he replaces it... This is a stock engine and time and experience has shown that the factory calibrated q jet is the only bolt on carb that runs well without re jetting... If this were a modified engine then sure an aftermarket carb is a good option but why try to do better than rochester engineers did?
If it was me I would put the qjet on it to find out if it ran different. If it run the same I would know its not the carb. Dan
