: Carb Question

09-02-10, 02:46 PM
My fellow Caddy enthusiast,

I have a question about my carburetor on the 89 Brougham with the 307, original carb. I wanted to post pics of the particular part of what I am asking about, unfortunately since I have joined this site, I have not been able to upload pics, they always fail...
Anywho, A while ago the "check engine" light started flashing and the car would run VERY rough, and cut off. It would do this every now and then, and eventually the problem just stopped. Every now and then the car would cut off right after started and idle roughly however. One day I was cleaning the carb, and I touched a plug on the front of the carb. It was an electrical connector of some sort. When I touched it, the car started to run VERY smooth, like it has never ran before, like a brand new car!! I unplugged this plug, and other than a couple stumbles here and there, and the "engine" light forever on, it runs like a dream. Does anyone know what the purpose of this plug that I unplugged. It is located almost directly in front of the carb.


09-02-10, 03:01 PM
which side of the carb?
It's either the TPS (driver side) or MC Solenoid (passenger side) I think.

09-02-10, 03:05 PM
Ummm.....it is the Drivers side!

09-02-10, 03:25 PM
That should be the throttle position sensor. What's happening when it's unplugged is that it's just dumping gas into the carb at a steady rate I think.

You may want to replace or adjust the TPS if unplugging it makes the car run better.

09-02-10, 03:30 PM
I see the part here on AutoZone, $30.99, to your knowledge, is it a hard part to replace?

09-02-10, 03:33 PM
I can def tell what you are saying, the smell is def evidence that I am running "rich"...

09-02-10, 03:46 PM
It can be hard to replace. You need to take the top off the carb. When I replaced mine on my 87 it ended up messing up the carb (was original carb, never rebuilt.) because the throttle pump was worn out and I guess opening it up caused enough of a disturbance to make it not function correctly. Anyways, I ended up having to buy a rebuilt carb because rebuilding one of these carbs looked like a pain in the butt.

You might not need to replace yours, It might just need to be adjusted. You can check it with a voltmeter easily. Just backprobe the connector with the engine off, key in the "run position". There are 3 wires, ground, 5v signal, and the TPS voltage. You want the ground and the TPS voltage. You can find the specific voltage range for your year/car online. I think mine was supposed to be right around .45 or something, not sure though. Search this forum for some posts about it. I made a few posts about it and posted some info in some other posts. :)

09-02-10, 04:05 PM
Don't get the one from auto zone. Get an AC DELCO TPS sensor.

09-02-10, 04:58 PM
You will ruin your catalytic converter if you run rich for too long...

09-02-10, 06:36 PM
Thanks Outsider I am going to check into that, and if I do have to replace it, I will be sure to get the AC Delco model....Jay as for my Cat, it was taken off about 4 years ago, so I dont have that to worry about, lol

water walkin warrior
09-03-10, 10:19 AM
You will ruin your catalytic converter if you run rich for too long...

Oops. I may be ruining mine. My wife says my car smells, I've probably gotten used to it. It does smell very "gassy" sometimes. So I'm probably running very rich. (I with my wallet ran rich.) I need to focus on getting the TPS adjusted or changed.

09-03-10, 10:27 AM
TPS and/or Mixture control solenoid? I don't know much about carbs...could maybe also be the float maybe? I dunno.

09-03-10, 10:45 AM
I had mine rebuilt a while ago, that has no bearing on the TPS does it?

09-03-10, 11:01 AM
If you had it rebuilt then they should have replaced the TPS while rebuilding it. Might just need to be adjusted. Since it was already rebuilt, you won't need to pull out the "plug" that blocks the TPS adjustment screw!