3100 sensor location

[94century3.1]

I am re-doing the intake gaskets on my 1994 buick century w/ the 3100 SFI engine. I seem to have misplaced a sensor connector, and can't seem to find where it goes. It comes off of the same harness as the coil pack, but even with taking everything apart again, I can't find where it goes. Any ideas? I have included a picture of the connector in question.

[tractorman]

That looks to me like the connector that goes to the evap canister purge solenoid. It's back by the rear valve cover, kinda behind the coil pack if I remember right. Damn hard to see and hard to get to.

[pocket-rocket]

I'll second the evap purge solenoid.

[3100 MPFI]

most likely the EVAP canister purge, HOWEVER, if it is more to the PASSENGER side of the car, it could be for an option you don't have. It might be the connector for the power steering pressure sensor on the variable assist power steering unit. I know my 1995 and my 1996 3100's were prewired for it.

this is the one for the power steering unit. I just tucked it behind the power steering pump.



if it is the canister purge that you are missing, it looks like like this one. This is the 1996 unit, so it has an added module that yours will not have, but it goes on a bracket that is attached at the back side of the bracket for the coil packs.

[94century3.1]

Thanks for the help all, turns out that there are 2 connectors that can fit on the evap. purge solenoid, I had that power steering one connected to it, so I switched that one with a spare one I had sitting on the driver's side an it ran better, I believe that the connector that 3100 MPFI has sitting by the steering unit is the same deal that I have. I still can't get it to idle right, though. Runs great while driving, but at idle it sounds like it's only firing on one cylinder. Would I want to clean the IACV? I have no codes being thrown.

[3100 MPFI]

first of all, when you turn your key on, does the SES light come on? I was not getting a check engine on my Grand Prix and it was because teh SES light bulb had burned out.

What spark plugs are you using. If they have BOSCH written on them anywhere, go back to the parts store, and get DELCO ones.

You can clean the IAC, but I think you should check for a SPARK, or FUEL problem.

When you pull the spark plug wires off of the plugs with the car running, does the idle change? If you pull them off, be careful you don't shock yourself.

[94century3.1]

Yes, I do have a SES light when the key is turned live. All plugs are firing normally, however, I un-plugged (what I believe) is the MAP sensor (Plugs into a square thing mounted on a short tube with honeycomb inside it). After I unplugged it, it idled fine. The intake tube did have oil coming out of it, and seemed to be pretty dirty, is there a way to clean it?

[3100 MPFI]

oil in the intake tube is kinda normal. I think they call it "blow by". I just clean it with CARB CLEANER.

Try this. Start the car, and unplug the FUEL PRESSURE REGULATOR.



Just undo the vacuum line on top of it. See if any FUEL comes out.

If fuel does, then your fuel pressure regulator is bad. When you go to get a new one, also get a new MAP sensor. Fuel in the MAP sensor will kill it.

Just to be sure we are on the same page, the MAP sensor is the one with the big GREEN connector. I just say that because you said something about honeycomb, and I have not ever really looked at it. I am just saying to to be sure we are on the same page.