Contour Enthusiasts Group Archives Forums General Troubleshooting 95 contour bogs out when throttle is depressed.

Hi all isn't the net great? I've got a 95 contour with the 2.0 ztech. 150,000 miles with little trouble. During the last year I have noticed that the car will not run very well when it is cold. Tended to idle rough almost stalling when the air pump kicked on. I simply let it warm up before running. The problem got worse and worse till the engine would die when given the gas cold. If the throttle was released it would pick back up again. Always seemed to run great once warm. Well the last 6 months I have had the check engine light flash on several times a day intermittenly. Really did not seem to affect how the car was running. Well finally the engine bogs out when given some throttle full time even when warm. I checked the codes and got the following codes during a Key on engine off test. Hard code 111 OK, Memory codes; 171,172,181,186,519,556.

171 and 172 appear to point to the Oxygen sensor not switching. I replaced the sensor with no effect on the problem. Ouch! I cleared the memory by unhooking the battery. Ran the car for 10 miles after replacing the sensor.

Some history on the car. The timing belt and tensioner was replaced around 60,000. I have recently replaced the plugs and wires. The engine does not really burn any oil. It has been awhile since I changed the oil. I ran a key on engine on test before and after with a 111 reported. I have checked the codes after replacing the sensor and all checks out ok even though the car runs like crap. I did notice that the car would chug badly when it was cold. Any ideas on how I should approach this?

I do have the manual, but it does not really help a novice with instructions like "to test the Mass air flow sensor verify that there is at least 10.5 volts between the "VPWR" and "GRND" terminals" Where the hell are these connections? I'm sure they are one of the 4 connections, but which? My MAF has the connections labeled A,B,C,D,E ect. Any help would be great, Surveyor

I had this problem when I first got my GL.
it went away when I cleaned the MAF, but still came back now and then.
I replaced the MAF and it hasn't done it at all since I replaced the MAF.

Were you able to test the MAF sensor? I would love to rule that out or replace it.

Could anybody provide some help testing a MAF sensor?

to test a maf sensor you will need a scope like a vantage or snap on shop scope the vantage is like 2 grand so i would call around to the shops in your area and see if they can test it for you,
if there is a college around that teaches shop id try them they will do it for like 20bucks and they wont rip you off.

Have you replaced the timing belt?

Before you get too involved with details, do the basics.

Clean the MAF element.
Replace the PCV valve and vacuum hose to it, check other hoses for damage.
Replace fuel filter, check fuel pressure.

Although MAFs can go bad, that is rare.

Yes I have replaced the timing belt at 60,000 miles. PVC was replaced around the same time. I will clean the MAF as it is easy to access and see if that makes a difference. Any warnings about cleaning the MAF sensor?

It's about time for another timing belt.

Spraying off the MAF element from the front is the easiest method. Electrical contact cleaner is perfered. No danger in that.

A cold idle that fluxuates high and low usually indicates a major vacuum leak.

Don't forget the fuel pressure. Fuel pump strainers plug up on Zetecs too.

Roughness at idle can also mean you need new plugs and wires, but this won't be causing your lean condition.

If you get your problem down to just hesitation, check the TPS. This is easy to do with just a meter, as it is just a potentiometer.

Cleaned the MAF sensor & replaced the fuel filter. Runs like a champ. I know it was probably the fuel filter, but I won't tell my wife that. She suggested the fuel filter at the beginning..but no I had to buy a oxygen sensor instead. The MAF sensor looked dusty to me. Could a little dust cause it to run poorly? Thanks guys.