[sbctruckman]

What plugs in on top of carb it looks like were something electrical plugs in there does it have to be pluged in for carb to work its in 86 Chevy halfton 305 4bbl quaderjet never seen one b4 please help

[cobalt327]

Originally Posted by sbctruckman

What plugs in on top of carb it looks like were something electrical plugs in there does it have to be pluged in for carb to work its in 86 Chevy halfton 305 4bbl quaderjet never seen one b4 please help

One plug is the TPS, the other is for the idle solenoid.

Unless the carb is specifically tuned for running w/o any computer control, the carb will not work well at all, w/o the ECM and the other sensors installed and working. Even w/the changes made to the carb to work w/o the ECM (mainly used for drag racing), it's not going to be anywhere near as good as a non-feedback carb on the street.

[joe_padavano]

Originally Posted by sbctruckman

What plugs in on top of carb it looks like were something electrical plugs in there does it have to be pluged in for carb to work its in 86 Chevy halfton 305 4bbl quaderjet never seen one b4 please help

Actually, 1986 was a funny year for Qjet carbs. As noted above, there were the computer controlled Qjets with the mixture control solenoid (two wire plug on the top front passenger corner of the carb) and the throttle position sensor (three wire plug on the front driver's side of the carb). These carbs require both the computer and the matching CCC distributor to work properly. The only trucks that got this carb in 1986 were those sold in California.

There was also a non-computer controlled Qjet used on the 1986 trucks that has a similar two-wire connector on the top front passenger side corner. This plug looks just like the mixture control solenoid plug, but there is no TPS plug on the drivers side of the carb and there is no computer. A normal HEI distributor is used. This carb has the dual-volume accelerator pump. The accelerator pump has a large shot for use when the engine is cold. As the engine warms up, a temp sensor closed the solenoid valve that is attached to that two wire connector, reducing the size of the pump shot. That's all this connector does. The metering jets and rods are the same mechanical design as on any other non-computerized Qjet.