: Tune up time...89 Brougham (W/ Olds 5.0)



AElayyat
12-28-06, 01:00 PM
Hey guys, I was getting ready to do a minor tune-up on my 89 Brougham w/ Olds 5.0. I got the spark plugs (AC Delco), pcv valve, breather filter, fuel filter, dist. cap & rotor. The spark plugs wires seem to be fine, but I'll check them out. Any tips on this car, because I am not too familair w/ carburated vehicles or the 5.0. I have more knowledge working on the good old 4.1 in my 85 FWB. Any tips are appreciated, thanks guys.

joe_padavano
12-28-06, 01:56 PM
Make sure all the vac lines are in good shape and connected correctly. The 307 has miles and miles of lines and a crack in any one of them can wreak havoc with the computer system. The big trick with the electronic Qjet is to use a dwell meter to set the mixture. Once you install your new parts and set the timing, connect a dwell meter to the green terminal in the harness in front of the carb. This will allow you to monitor the duty cycle of the mixture control solenoid in the carb. With the engine fully warmed up and at idle, read the "dwell" on the SIX cylinder scale of the dwell meter. The reading should vary slightly up and down in response to the O2 sensor. If the reading is not moving at all, either the O2 sensor is not warmed up enough (run the engine at 2000 rpm for a minute or two) or you have another problem. Assuming everything is working, adjust the two idle mixture screws to get the dwell as close as possible to 30 degrees. The screws have the "double D" heads that require the special adjusting tool. That's all there is to it.

AElayyat
12-28-06, 04:07 PM
Make sure all the vac lines are in good shape and connected correctly. The 307 has miles and miles of lines and a crack in any one of them can wreak havoc with the computer system. The big trick with the electronic Qjet is to use a dwell meter to set the mixture. Once you install your new parts and set the timing, connect a dwell meter to the green terminal in the harness in front of the carb. This will allow you to monitor the duty cycle of the mixture control solenoid in the carb. With the engine fully warmed up and at idle, read the "dwell" on the SIX cylinder scale of the dwell meter. The reading should vary slightly up and down in response to the O2 sensor. If the reading is not moving at all, either the O2 sensor is not warmed up enough (run the engine at 2000 rpm for a minute or two) or you have another problem. Assuming everything is working, adjust the two idle mixture screws to get the dwell as close as possible to 30 degrees. The screws have the "double D" heads that require the special adjusting tool. That's all there is to it.

Joe, thanks for the response. But that procedure that you described seems easy but I'm still an amature. If I had a working timming gun I would check the timming but the only thing I'm going to do are the simple ones (plugs, dist cap & rotor, fuel filter, pcv valve, breather). I'd rather not take the chance and screw with the carb because from what I can tell is that it is adjusted and doing good (knock on wood).