oh yes, I just remembered another thing. The exhaust, after any duration of running, smells slightly of gasoline. There are signs of soot on the rear valence and exhaust tip. i have held a napkin behind the pipe and had it slowly turn black.... so this seems to indicate that the fuel is not leaking before entering the engine?

 

What about the DME Temp II sensor?

BTW, I used to get 450 miles between fillup and reserve light when I was commuting a 100 mile round trip three times a week.

 

Ok, so I have done some more tests and such. The (new) oxygen sensor is reading a very steady .49Volts at idle, and steadily increases voltage as rpm go up. What I am reading from the fact that it can change, but doesnt bounce around at any speed, is that the O2 sensor works but that the car is ignoring it, instead running on unaltered fuel maps.

I also checked the fuel quality switch, it was where it should be (position 0, full CCW)

I am now wondering if the cuplrit is the engine temp sensor, since the manual states (and those responding to this post) that the engine will run rich with a broken temp sensor, as it will ignore the O2 sensor.

I went to test the temp sensor with my multimeter, but couldnt get to the connections in a practical way. I couldn't fit my hands on the engine side of the connector, (without removing intake tube) and could not find the one under the dash. If my temperature gauge in the dash reads correctly, is the sensor working right?

 

Put your car on a sniffer and check emissions! A qualified tech. should be able to see whats going on right away. No more guessing/swapping parts and spending $$$.

 

Engine temp sensor huh?
I get arround 15-17 city driving and at the last fill up 19 with greater amount of highway driving, if you can call I95 in Ft. Lauderdale at rush hour highway driving. Guess maby I ought to check that little puppy out. Anybody got some hints on how to do it?
Bill

 

The dash sensor uses a seperate sensor, sorry.
You should be able to unhook the sensor at the DME, and test it there. Let me look in my manuals tomorrow and I'll try to get you some pin numbers.

Near as I can tell, to check it at the sensor, you have to pull the intake manifold.

 

yeah.... from what I saw, based on the size of my hands, I would need to at the very least pull off the rubber elbow tube to unplug that sensor.

What worries me about doing that, is the tubes which plug into this tube. They seem to be attached with crimp pieces rather than hose clamps. To get the tube off would I just cut these clamps off? I dont think I have a tool to redo the crimps... would hoseclamps work for reassembly?

 

bill - sounds like you need an 02 sensor. buy one at napa (universal for $20) and solder it onto the line. i have this in my '84 and it works like a champ. i couldn't get more than 20 hwy with a bad 02. the last automatic parts car i had had a shot O2, and got very poor mileage on the way to titusville.

-Michael-

 

Michael,
Thanks, I'll give that a try. Ohhh Boy, another thing to add to my 100,000 mile things to do list.
Talk to you later,
Bill

 

When I look at mine, some of them have been replaced with hose clamps.
However I know I have a couple vacuum leaks, so it beats me if it's right =)
Only thing is, once you take all that apart, you better hope it was the problem, otherwise it is quite tempting to kill it.

 

and Elf gets the prize! Took it into the shop finally (I had given up)
Turns out it was somewhat rich, they tuned it right on the emissions machine. But the big thing, my odometer is recording 60% actual mileage. Enough to fool me into believing my mileage was horrible, but not so drastic I got suspicious. Blast! Oh well... they washed the car too. So it was a $90 fine tune and wash. Just ordered the part, I expect some odometer teeth to be gone when I crack it open.

 

Glad to hear that you figured out the problem. I guess we should put 'check odometer' on the list of possible gas mileage problems.

 

So, what was it that they actually did to lean-out the mixture?

From what you said about the smell of gas and soot around the exhaust tail pipe,
it sure sounded as if it was running rich.

 

Im guessing that they messed with the adjuster screw on the Air Meter, adjusting it till their emissions machine said it was burning clean. Supposedly, its now running cleaner than most MY2000 cars. Should help with the mileage. The odometer explains why every sensor I checked came out good.