short version : truck misfires and stumbles terribly when warm after it sits for a minute. gets a little better when moving.




longer version
95 300ci 4x4 5sp

Having a difficult to diagnose problem here guys.

If I start the truck up from cold, and run for a good while, say 100 miles on the interstate, it will drive fine until I stop for a couple minutes and restart. It will then drive terribly and misfire so bad I can barely get it going. Once I get going it will drive a lot better but not 100%. Appears to be something affected by the heat while it sets (sensor?). While I am driving now it will throw a code, usually when I go up a hill, but also sometimes downhill or flat. Code has been 181 or 172 (lean or rich from the 02 sensor)

Also has thrown code 565 for a while, even before this problem. That code is Canister Purge Solenoid Circuit Malfunction. Could that have anything to do with this? I do not understand the function of this canister or its purge solenoid. I have pulled that code a couple times in the past, it is just stored and does not turn the check engine light on so I never thought too much of it.

One last 'issue', is the motor will vibrate a bit at 1500 rpm in 4th gear at 45MPH only, feels like a tire out of balance but is obviously the motor, thought it could be a vacuum issue but never could find it and smoke test showed nothing. Could this also be related?

Truck has about 100k miles, well maintained, no vacuum leaks that I could find (smoke tested), replaced distributor, ICM, plugs, wires.

Help?

 

bump. anyone?

 

No one???????

 

I wish I could help you, bkbkbkbk, but mine is carbureted. Sorry.

 

Thanks 1986..

I wont be offended if people just start taking a rough stab at it...

 

bump... some one has to have a guess. EGR related? If it is throwing lean it may be getting way too much air after heat soak?

 

Do a Google search on the codes like this: ford codes 172

Do that for each of the codes and see what comes up.

 

Spent plenty of time doing that with no significant luck.

 

Dirty MAF sensor? truck does not have one
Could the EGR be sticking open? Wouldn't the EGR position sensor send a code because of this?

 

BUMP

Throttle position sensor??

 

I never post anything much. I count on the search function to answer my questions. I am having the exact same problem that you are experiencing with the same code 565. My truck is a 95-300-I6 with a 5 speed. My gas mileage is off 3-4 miles per gallon. The power loss is very noticeable and it is sometimes hard to re-fire after running any period of time. I would love for some of the guru to help us figure out this problem.

 

I have a donor truck that I have swapped out all the different sensors and even the egr. The only thing I haven't changed is the air pump. I have correct vacuum on all components with no vacuum leaks. I am really stumped. I haven't any of the coolant sensors yet. I feel the it is exhaust related somehow. I have read about a possible intake/exhaust leak. I am about to do an engine swap with a replacement 6 cylinder but need to solved this problem first because I don't feel changing the engine will make this go away. Any suggestions would be greatly appreciated.

 

this thread is a dud