Contour Enthusiasts Group Archives Forums General Troubleshooting Engine & Idle Problems

Here it goes. I have a 96 zetek sport, 5 speed, with 75K on it. My CEL came on about a month ago, got the code pulled and it comes up as a P0171. The symptoms seem to be a hunting/rhythmic idle. It is most noticeable the first time I start the car each day, and lately it has stalled out a few times. After a bit when the engine gets warm it calms down for the most part but idles a little above 1K. Another problem with the car that only adds to this, and has been a problem since I got the car, that occurs approximatley between 1500 and 2000 RPM's. When pushing on the gas just a hair to get it in this range, the idle starts to jump considerably, but never stalls out. It shoots down to like 500 then back and repeats itself until I give it more gas and climb above 2K. Everything above that is fine, but this is a real pain.

Before I start to buy parts I could use some of your collective wisdom. I changed out the PCV valve before the CEL came on, I cant remember how long before it was however, I would say less then a month. Not sure if this would have any effect. I am heading home from school this weekend and going to attempt to find whats going wrong. I worked on a golf course back home over the summer and can use the shop they have there. They got a lift and every tool you could want, so its a good perk.

Thanks in advance for any help, I really appreciate it.

The following is from the Ford TSP:

Diagnostic Trouble Codes (DTCs) P0171 bank (1) (cylinder #1) and DTC P0174 bank (2) indicate the fuel/air ratio is too lean. The fuel adaptive system is at the rich correction limit.

DTC P0172 bank (1) and DTC P0175 bank (2) indicate the fuel/air ratio is too rich. The fuel adaptive syste is at the lean correction limit.

DTCs HO2S Reference list:
-- HO2S-11 = DTCs P0171 and P0172
-- HO2S-21 = DTCs P0174 and P0175

Possible causes:

Fuel system
-- Excessive fuel pressure.
-- Leaking fuel injector(s).
-- Leaking fuel pressure regulator.
-- Low fuel pressure.
-- Contaminated injector(s)

Induction system
-- Air leaks after the MAF.
-- Vacuum leaks.
-- Restricted air inlet.
-- PCV system.
-- Fuel purge system.
-- Improperly seated dip stick.

EGR
-- leaking gasket.
-- Stuck open EGR valve.
-- Leaking diaphragm.

Base engine
-- Oil overfill.
-- Cam timing.
-- Cylinder compression.
-- Exhaust leaks before or near the HO2S's.

* Check air intake for leaks, obstructions and damage.
* Check air filter, air filter housing for blockage.
* Verify integrity of the PCV system.
* Check for vacuum leaks.


Two things from the list come to mind:
- You might have a possible vacuum leak somewhere. Start the engine and listen for a hissing sound. Also look for hoses that have imploded on themselves (while the engine is running) and check all hose connections.
- You didn't replace the PCV valve correctly. Did you use a Ford PCV valve replacement?

I had the exact same problem, with the same year and engine. I went through everything, including the oxygen sensors. It ended up being the MAF sensor. If you feel experienced, you can take the cover off the maf sensor with a security star (T20) bit, and spray two filaments (that look like filaments in a lightbulb) with o2 safe carb cleaner (like gumout (i think that's the name of it)) and then let dry. Then put it back in, just make sure you disconnect the connection to it while you do this. This fixed my car, of course if you don't feel secure doing that, you can buy a new one (it's 90 something dollars at autozone, if you bring the old one in with you). Hope this helps!

Thanks for the advice, Ill take the MAF out this weekend and give her a cleaning. I have cleaned it before with electronic parts cleaner, but only from the side after taking the air box cover off. If not looks like Ill be heading to autozone for a new one.

GeoPappas : I now remember a while back that when I had the hood up, I turned the engine off and went around to the front. I heard a hissing sound, sounded like air being released, coming from the rear left area of the engine compartment, in the general area of the power steering fluid resevoir. Ill have to give it a closer look.

Heres the part on autozone.

CARDONE MASS AIR FLOW SENSOR for a 1996 FORD CONTOUR

Unit Price: $92.99
Core Value*: $60.00
Part No.: 74-9522
Weight: 1.15 lbs.
Warranty: 3 MO

It says you get back the $60 core value when you return your core (I guess thats my old one). If so, $32.99 seems almost too cheap.

Well that would be great if that is the case, but they told me when i checked it out that the 92 dollars (or whatever you said) was AFTER the core charge has already been taken off. Now if I have mistaken, and you get it for 32 dollars.. more power to ya.. I actually hope that's true! I hope it works out for you.

i've been told that my car's jumpiness at low throttle may be due to too much air,, maybe i'll clean my MAF.

Originally posted by Kremithefrog:

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i've been told that my car's jumpiness at low throttle may be due to too much air,, maybe i'll clean my MAF.

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Is there such a thing as too much air?

Unit price is considering that you HAVE a core.

w/o the core it is $60 more...


Trade your core it is 92.. keep your core it is 92+60.. ouch



Ray

Yeah. I just gave them a call and that is what they said. $92 + the $60 charge which they refund when you return the core... damn.