Running rough...suggestions on what to test?

[91waggin]

Wait....you said the charcoal canister has been removed? Here's the thing: The computer expects the charcoal canister to be there, and sometimes it opens that solenoid to vent the excess fumes from the canister into the intake. Now I THINK that the computer will lean the mixture slightly in order to compensate for the fumes coming in. If you're not getting those fumes to come in, you might have a lean condition until the computer figures it out again.

I was just rereading your thread and saw that you had the charcoal disconnected and it got me to thinking.

[1990LTD]

Wait....you said the charcoal canister has been removed? Here's the thing: The computer expects the charcoal canister to be there, and sometimes it opens that solenoid to vent the excess fumes from the canister into the intake. Now I THINK that the computer will lean the mixture slightly in order to compensate for the fumes coming in. If you're not getting those fumes to come in, you might have a lean condition until the computer figures it out again.

I was just rereading your thread and saw that you had the charcoal disconnected and it got me to thinking.

I've got mine venting to atmosphere and no goofy running problems to speak of.

[91waggin]

Huh. Dunno then.

[1990LTD]

Huh. Dunno then.

No fuel smell either. Maybe the canister just doesn't work on my car

[PushnFords]

My car would do that, it's a lean out condition in my case. Do this for me. Start the car. Let it idle (if it's warmed up this shouldn't take too long). Let it idle for a few minutes, see if the idle drops down and it starts to run weird. Rough idling, acting as if it will stall, stuff like that. It will then appear to rev, and then drive fine, until you start the engine again.

It rarely runs rough at idle. Usually just when there is a slight load on the car like sitting in gear with my foot on the brake or driving around town. After I put the MAP sensor on it had a slight miss on the way back to work and has been fine since then. If it starts to miss again I'll try that but in the past I've let it idle for extended periods and never had a problem.

No fuel smell either. Maybe the canister just doesn't work on my car

No fuel smell in my car either. I unhooked it because the canister got smashed somehow...the hose connections are busted off.

[PushnFords]

I'm cautiously optimistic....but the car hasn't missed since I threw the junkyard MAP sensor on. I still have lean codes on both banks but I'm really starting to think that is just the O2 sensors being fried. Either way I wanted to get rid of the miss before I replaced them. I'll give it a few more days before I order the sensors....

[91waggin]

How long has it been since you put the MAP on? I would love to know if I was right.

[PushnFords]

How long has it been since you put the MAP on? I would love to know if I was right.

I installed the MAP sensor on the 18th but didn't drive the car Fri-Sun. So...four days of regular driving so far.

[91waggin]

....and so we wait

[sly]

*insert Jeopardy theme*

[PushnFords]

I noticed a slight miss a couple of times yesterday and today it was pretty bad. Guess the MAP wasn't the problem. It was 10 days between occurrences...at this rate I might figure it out in a couple of months.

[91waggin]

Damn. The vacuum hose to the MAP is in good shape, right? No leaky?

Test the TPS. Could be that, especially if it's running crappy at idle and then will be okay once you put your foot on the gas.

[86VickyLX]

Have you checked for continuous memory codes?

[PushnFords]

Damn. The vacuum hose to the MAP is in good shape, right? No leaky?

Test the TPS. Could be that, especially if it's running crappy at idle and then will be okay once you put your foot on the gas.

I had a bunch of vacuum leaks when I bought the car so I pulled the plenum and replaced all of the lines connecting to the engine. Rock solid vacuum reading now.

I haven't tested the TPS...it looks pretty new. The thing is...I don't have to touch the gas to change how it runs. A couple of times I'll be sitting there in drive with my foot on the brake and the engine will rev slightly and it'll even out...and I never moved or changed anything.

Have you checked for continuous memory codes?

I posted them earlier in the thread...Bank 1 & 2 are both lean. Fuel filter, pump, and pressure regulator are all new and fuel pressure was within spec when I tested it.

[86VickyLX]

No, since you've cleared the codes. you have cleared the codes right? Continuous codes are shown in KOEO mode.