[GonicGM]

Looking for help in identifying year of this factory Buick 3.8 Turbo 4bbl carbureted engine. Should be 78-83 but looking to narrow it down. The site 'beforeblack' has casting number info to narrow it down. Distributor is non-ECM with vacuum advance. What is odd about it though is that it has an odd secondary plug from the distributor body. It is a 4 pin square that looks identical to a TH700R4 case plug however, the leads are just a few inches from the distributor body. Block casting is 25506397. Yes, I am aware of casting date codes and may eventually find them but the motor is conjested, in a dark place and three hours from where I am.

[GonicGM]

One more image.

['ol Pinion head]

Looking at the pics, 1980 or earlier, unless parts have been swapped and wiring harness has been stripped out. The "odd" secondary plug on side of distributor goes to stand alone electronic spark control box. Qjet appears to be 1980 M4ME style Qjet similar boost referenced Q-jet as also used on '80 turbo 301's.

On the '81-83 turbo 231's and '81 turbo 301's they receieved E4ME Qjets... have the bluish plug deal on top of the front of the airhorn, but as turbo carbs are also special, as have power enrichment circuit referenced to boost. the 81 style turbo engines had a maze of wiring hooked up to MAP sensor, a o2 sensor...and eventually the C4 computer.

[GonicGM]

Originally Posted by 'ol Pinion head

Looking at the pics, 1980 or earlier, unless parts have been swapped and wiring harness has been stripped out. The "odd" secondary plug on side of distributor goes to stand alone electronic spark control box. Qjet appears to be 1980 M4ME style Qjet similar boost referenced Q-jet as also used on '80 turbo 301's.

On the '81-83 turbo 231's and '81 turbo 301's they receieved E4ME Qjets... have the bluish plug deal on top of the front of the airhorn, but as turbo carbs are also special, as have power enrichment circuit referenced to boost. the 81 style turbo engines had a maze of wiring hooked up to MAP sensor, a o2 sensor...and eventually the C4 computer.

Thanks for the insight. I haven't pulled the rotor. Are you suggesting that there is a vacuum advance, no mechanical weights, rather ESC?

The carb appears unoriginal as it has a p/n 7045XXX, and decodes as 75 OLDS.

[CraigGT37]

Looks to be an 80 block. They moved the knock sensor to the rear under the EGR valve for the 1980 model year. They did use an ESC for spark control for 78-80, until the computer command control system came out in 81 for them.