I am working on a 3.8 normally aspirated Buick V6 in a 82 Old.s and I need a little help. The car sat for two years and I never could get it to run right, I have rebuilt the carb.( 2 differant carbs) , Replaced the oxygen sensor the purge valve, the idle control and a lot of vacuum hoses but it still isn’t right. It starts ok but once it goes in to close loop it idles to slow “sometimes”, and when you put it in gear it stalls other times it is ok. It also has no bottom end. Once it gets up to high way speed it is ok. I set the TPS like the GM manual says at .97 volts on the fast idle choke cam, with the dwell meter on the MS lead at idle I can’t seem to get it any lower than about 32 or 33 but it is with in the 25-35 spec. What can I check next? If anyone could point me in the right direction I would greatly appreciate it. Oh the next thing I plan to check is the coolant temp sensor but I don’t think that is it. Oh there are NO codes in memory.
Ok I have a few new developments, it almost will not idle at all in gear now I am getting a code 45 (rich oxygen sensor) this is why I rebuilt the carb. , poor gas mileage and surging at highway speeds. I have not had a chance to change the coolant sensor yet.
I'm not going to be much help here but I have a 82 Regal 3.8 NA that I drive to work everyday. It runs great but one day I noticed the vacuum hose to the EGR valve was rotted so I replaced the hose and it ran like crap afterwards. If I leave the hose disconnected it runs great. I would think since your car is running rich and the problems start when it goes the closed loup you might check the EGR solenoid or EGR valve.
How are your ignition components? cap rotor? plugs, wires? also recomend a compression test you should have at the very least 110-120psi in each cylinder. also your vauves may be to tight has anyone else had the car befor that may have mal-adjusted them? If all this dosen't work I would try unbolting the converter and seeing how it runs without it, if it runs better you need a new one.
Hope I have been of some help...
This has been a on going problem for sometime now, my wife has been driving the car for the last 2 years or so but has just become un-driveable lately. Up till now the idle would slow down till it would almost stall but like I said you could drive it (it bugged me but). But now it is impossible to deal with.
Now I have not checked compression, the valves are not adjustable, the plugs and wires are new and the cap is not very old but I had not thought of checking the converter, so I will try that and the compression test and I think I will pull the EGR valve to make sure it is seated properly too. After that I am out of ideas other than maybe the ECM but I don’t think that is it. Oh and I have changed the temp. sensor with no change.
You might try 2 things...replace the TPS. I had one give similar problems because it was just plain worn out. Second, check for play at the shaft ends of the butterflies. These will wear the hole out to oval shapes and the carb will stumble from the additional air sucked in the ends of the shafts. This can be cured by having the carb machined and new bushings inserted to clean up the endplay.
Thank you to Eric, Mick and Dan for you’re input, I have found one of I guess a few things, the pipe from the air pump to the intake was leaking where it screws into the intake. I found it when I pulled off the EGR valve. Now it idles better, it still has not got the throttle response I think it should have and it still idles down slower than it should but it is a big improvement. I am also getting a code 44 and a code 45 (lean and rich O2). I plan to go back through the carburetor adjustment and see if it will improve (before I could not get dwell on MS below 32 or 33) I would like to see it at 30.
I got a new TPS but looking at the old one it seems fine, you can go through the throttle range and the voltage goes up and down nice and steady with no opens. The throttle shafts seem to have no play.
Thanks again guy and after I do my adjustment on the carburetor I’ll let you know where I am at.
P.S. still plan on getting the converter checked to make sure it is not plugged.
I once had a carb that was warped on the top. You couldn't tell unless you put a small feeler gauge across the top of it.