HEy everyone, im trying to fix a problem on one of my vehicles to sell it and go towards a durango for my wife. The problem im having is starts right up, idles fine in gear,as soon as i put it in reverse or drive, the car gets a rough idle(i can feel the motor shaking in the steering wheel). When i got the car it had a misfire on cyl 1 so i changed plugs and wires and erased the code and that fixed that problem but still rough idle. Been about 5 months sine the plugs n wires still no cel. Ive cleaned the maf sensor,nothing. Just tested the fuel pressure and it read..
Key on,car off--38psi
Car on--32psi
car on in gear--34psi
car on, reghulator line off--43psi
When i turn the car off and take the key out, it does not hold the pressure. At first it appears to but it drops about a psi every minute. Would this cause a rough idle in gear only? Any other suggestions? Because its not a dodge im not looking for a diagnosis but maybe just a general idea. I value this forums advice and knowledge. Car is a 4cyl 96 Ford contour with 64k miles. Again just asking for any general ideas so i can fix and get rid of this ford and get my wife a dodge. THANKS!!!

 

Also, if the above wouldnt cause that, would a stretched timing belt cause shaking at idle in gear only?

 

Hold pressure should be 26pounds,there's some sort of pressure sensor that gos bad on those..sry that's all I know about those.. other pressure's about right....

 

so your sayin itll slowly drop to 26psi than stay?

 

He is saying that if pressure stays at or above 26 psi, it is good.

Not really much to go on.

When was last tune up?
What does cap and rotor look like?
is this a coil on plug engine?
Is it using oil?
Check TPS.
Check IAC.
Since it is not throwing codes, do you have a scanner that can read live data? If so, check what the values are against what it should be doing.

 

like i said about 5 months ago i did plugs n wires, no cap and rotor on this car, not using excessive oil, I have a obd scanner and thats it. Been doing some research and seen that on many vehicles an 02 sensor can cause this, I did notice on the car,it has a coup le little holes in the muffler so Im wondering what condition the cat is in. If the cat was bad would the 02 sensor change the air ratio and cause this?Ill have to redo the fuel test because I didnt leave it on long enough for it to drop below 26 so not sure where it woulda stopped.

 

26 is with it running.

If ther is no cap then it may be coil packs. But they would probably throw a misfore code.

O2 would make it run rich or lean. If scanner cannot show live data, ther isn't much way to tell.

Cat being clogged could cause it to bog down then die.

Unplug upstream O2 and see if anything changes.

 

ill try the 02 tomorroww, I was hoping that the cel would come on at some point to help me diagnos this but no luck. The car has died twice on me and both times was after ive driven for awhile and i stop at a light and either make a uturn or hard turn i think the power steering puts a load on the motor and drops the rpm's and since its already low(from rough idle) it just killed it. Started right back up and drove fine. Driving down the road and even on freeway going 75 its smooth no problems.

 

What are you working on?

 

"4cyl 96 Ford contour with 64k miles"