Contour Enthusiasts Group Archives Forums General Troubleshooting Idling problems, what to check?

All of a a sudden my contour is acting strange. When i'm driving in gear and then throw it in neutral, while still moving, the idle falls real slow and then once it drops to 1000 rpms it just falls all the way to 0 and stalls while still moving. I'm going to clean my IAC 1st and then the Mass air sendor but how do i check for vacuum leaks? what else should i check? the CEL light is on but i have yet to check it. However, the CEL was on before any of these idle problems ever happend. thanks

coil, spark plugs, wires, IAC valve (not sure on that)

I don't want to hijack the thread but my 96 contour SE has stalling problems too. After changing my IAC Valve, MAF, Spark Plugs and Coil pack, It still stalled. So I took it to the dealer and they told me that I needed my manifold gaskets changed. They were going to charge $200 for the job. Would this be right?

CEL 171 and 174. Pcv Hose has been checked.

There is an easy fix. Did itmyself yesterday in about 20 minutes and 35 cents. There is a post in FAQ. They call this Moosing. There is a hose where the air intake hose meets the throttle body. This hose is attached to what looks like a small juice can that has a hose that goes to the back of the manifold. All easy to see and get too. Disconnect the hose at the manifold, you will need a 1/2 inch copper pipe end cap found in your local plumbing dept. you will insert this into the hose pushing it in far enough to be able to reconnect the hose to the manifold. But you will need to drill a hole in the middle of it first. I started by drilling a small hole into it and kept making the hole larger until I got the car to idle correctly. This is what took up 15 of the 20 minutes. I ended up with a #27 Drill or .147. Once this is done put it in the hose, re attach hose and start car. I restarted the car several times to be sure everything reset itself. a lot better than $200.00

i just pulled the codes for the CEL and it came up as
P0171-P0174 Lean on Banks 1 and 2
PO161 - Downstream Heated Oxygen Sensor Heater circuit fault - Bank No. 2.

for the P0161, do i need to change the O2 sensor

FWIW, my dad drove my car the other day and filled it up with 87 octane, i usually use 93. About 15 miles after he filled it up the CEL came on for the first time. Now about 2 weeks later and 150 miles i go to check the codes and thats what i got. i've been filling it up with 93 octane every 50 miles to try and balance out the mixture and hope it solves my problem.

What do you think?

The 87 octane has absolutely nothing to do with the fault codes. Unless your owners manual specifically says to use anything other than 87 octane, you should not be using the higher octane anyway without a specific reason to do so.

For the P0161 code, consult the troubleshooting section of the service manual or CD. The fault may be due to a defective O2 sensor, defective wiring/connections, or a fault in the PCM. Just replacing the sensor based on the code might or might not fix it since no troubleshooting will have occurred.

For the 171 & 174 codes, see one of the many recent threads on those codes for advice.

Steve

it's an SVT and it says on the gas guage to use premium fuel only. i also remember readin somwhere in the owners manual to use 91+ octane.

Could my idling problem be a vacuum leak? It doesnt seem to me like a vacuum leak becuase it doesnt happen all the time. Sometimes it drops to idle normally and other times it just falls to zero but when it does idle it idles beatifully. any suggestions on what to check for other than the IAC?

my moms explorer got the same codes. it needed a lower intake manifold gasket. the labor was about the same ($200). the gasket is 20-25 bucks. idled real rough on startup. unless u can do it yourself, the labor charge is the [censored].

Your idling problem is most likely either the IAC or the vacuum leak. If the leak is bad enough, the IAC will not be able to properly meter air past the throttle place causing the idle speed to constantly overshoot or undershoot.

Since you didn't previously specify that you have an SVT, I had qualified my previous response. In any event, the engine will run just fine on 87 octane as will almost any current or recent Ford engine. You might loose a bit of performance on the higher compression engines, but it will still run fine unless there are other problems that the octane is masking. My Navigator has run perfectly on 87 for a long time. I only put higher octane in it when I know I will be towing my boat.

Steve

ok well i drove it today and it ran absolutely fine. when i threw it in neutral the idle dropped to 1k and then once i finally stopped it settled at 800. absolutley now problem. yesterday i cleaned the TB and recet the computer by taking the batter cable off. it cleared the CEL but it came back on after about 20 miles so i dont know what to do. hopefully it will remain alright. any other thoughts?