1991 LTD Crown Victoria Problems

[86VickyLX]

Hey guys, a friend of mine with a black '91 has a few problems, one of them I found is a hole in the pipe for the smog shit. It's the metal pipe that connects to the check valve. I think it's the one that connects to the heads, not entirely sure though. I noticed the hole when the engine was revved, it shot out whitish smoke from it, and it kinda sounds like it has an exhaust leak, it's loudish.

It has some idling problems, I pulled codes on it in school, it threw codes for the EGR valve, which I noticed, was plugged up with a rubber cap, and the hose for it was plugged up with a screw That was code 34, so I'm gonna assume that the code is gone now.

It also threw codes 12 & 13, the RPM not within self test limit. Which I had already considered since it stalled on me as I was pulling into traffic. At startup the idle goes very high, then bogs down real low, then levels out.

Also pulled code 21, good old ECT out of range code. The car was at normal operating temperature, so I'm gonna assume that that code is legit.

Oil is also leaking at the pan, from the front and the back, the bottom of the bellhousing on the tranny is covered in oil, and it has oil on the bottom of the timing cover, so I guess it's going to need an oil pan gasket.

What I found was weird is that it's a '91, when the dash changed, didn't they get an actual check engine light? It wasn't on and it had all these codes, it doesn't make any sense to me. The light does work.

The airbag light is also flashing, I do not know what for. I think it flashes 6 times then stops, then flashes again.

I told him to check out the site, and he said he'd join up.

[mrltd]

Don't ASSume anything. It is very possible that the valve or sensor or both is bad and it's VERY common to have completely clogged EGR passages.

The oil leaks can be from some other places.... would have to clean it up and comfirm.

ECT is very common, cheap fix for a lot of issues.

As for the seperate check engine, even if it has codes does NOT mean it'll set off the MIL. I have NEVER ever seen a MIL light come on with any of my cars with current codes. Also add in all of the cars I've worked on over the last 20 years.

[86VickyLX]

Don't ASSume anything. It is very possible that the valve or sensor or both is bad and it's VERY common to have completely clogged EGR passages.

The oil leaks can be from some other places.... would have to clean it up and comfirm.

ECT is very common, cheap fix for a lot of issues.

As for the seperate check engine, even if it has codes does NOT mean it'll set off the MIL. I have NEVER ever seen a MIL light come on with any of my cars with current codes. Also add in all of the cars I've worked on over the last 20 years.

Ok, I'll let him know.

What do you think about that pipe? For the clogged passages, someone must've put the screw in the hose and the cap on the EGR valve.

[mrltd]

obviously the pipe needs replacing....or completely remove the smog system

[trwp72]

The light on mine only comes on for a second, when it throws a code... I guess to let you know that it just recorded a code... The EGR needs to be checked... see if it is good... (pull suction on it and see if it loses the suction over time...) Second, pull it off and check to see if it is gummed up in tha passages.. If so, clean it out with a small wire brush and carb/ FI cleaner. Another thing is the EGR valve position sensor... it may be bad. (about $40.00 at Advance)

The idling issue may be a dirty butterfly in the intake... Take the large hose off coming from the air filter box, have someone hold the accelerator pedal down (ENGINE OFF!!) And then spray both sides of the butterfly and around the circumfrence of the opening... then use a screw driver wrapped with a CLOTH rag, and wipe it out... just spraying it will not work... it needs to be wiped down. Then wipe down both sides of the butterfly plate... until the rag comes out clean.... The butterfly being dirty will cause the car to idle low, once you clean it up, it should idle back to normal specs... I know this sounds crazy, but it works.... if it still idles weird... either low or idles up and down... change the throttle position sensor... These go bad often, since they are right on top of the engine... So the heat kills them... I have to change mine about once a year....
(Also about $40.00 at Advance)
Also you talking about the air pipe going across the back of the engine? Sort of hard to replace... but not real expensive... If you do remove the smog stuff... you will still need to block this off....

Hope this helps...

[86VickyLX]

The light on mine only comes on for a second, when it throws a code... I guess to let you know that it just recorded a code... The EGR needs to be checked... see if it is good... (pull suction on it and see if it loses the suction over time...) Second, pull it off and check to see if it is gummed up in tha passages.. If so, clean it out with a small wire brush and carb/ FI cleaner. Another thing is the EGR valve position sensor... it may be bad. (about $40.00 at Advance)

The idling issue may be a dirty butterfly in the intake... Take the large hose off coming from the air filter box, have someone hold the accelerator pedal down (ENGINE OFF!!) And then spray both sides of the butterfly and around the circumfrence of the opening... then use a screw driver wrapped with a CLOTH rag, and wipe it out... just spraying it will not work... it needs to be wiped down. Then wipe down both sides of the butterfly plate... until the rag comes out clean.... The butterfly being dirty will cause the car to idle low, once you clean it up, it should idle back to normal specs... I know this sounds crazy, but it works.... if it still idles weird... either low or idles up and down... change the throttle position sensor... These go bad often, since they are right on top of the engine... So the heat kills them... I have to change mine about once a year....
(Also about $40.00 at Advance)
Also you talking about the air pipe going across the back of the engine? Sort of hard to replace... but not real expensive... If you do remove the smog stuff... you will still need to block this off....

Hope this helps...

It does help, thank you very much.

[Tiggie]

You can patch that smog pipe up with some conduit and a little brazing. It worked well on my '82 for about five years. If it's too rusty, you'd be best off to get a new one. They were about $45 bucks when I bought one last time.

The EGR code is extremely common from what I've seen. My '88 consistantly has that code and the ECT code. I replaced the ECT and no change. The car gets an honest 23 MPG and runs fine, so I'm not messing with it. I would try to clean the EGR and test the EGR position sensor, and replace the ECT sensor anyway anyway to see if it helps in your case.

On cars this old, it's probably leaking a little from everywhere. Clean it and look again after driving it. Gunk works wonders.

[gadget73]

The check engine light will come on for only a few things. EGR being unhooked isn't one of them, but if the egr is hooked up and stuck open, it will light. Theres a few other things that will trip the light but its not that useful of a trouble indicator. As you've noticed, the car can run like crap and not give any lights.


Change the ECT and reset the computer, see what that does for it. Standard maintenence stuff is also important, plugs, wires, cap, rotor, fuel filter, air filter. If all that is good, and it still runs funny, start looking for vacuum leaks and other issues. The smog tube will make noise, but thats about it. Shmutz some jb weld or that magic high temp epoxy play-doh stuff on there to seal up the leak, or ditch it completely at his option.

[gadget73]

The check engine light will come on for only a few things. EGR being unhooked isn't one of them, but if the egr is hooked up and stuck open, it will light. Theres a few other things that will trip the light but its not that useful of a trouble indicator. As you've noticed, the car can run like crap and not give any lights.


Change the ECT and reset the computer, see what that does for it. Standard maintenence stuff is also important, plugs, wires, cap, rotor, fuel filter, air filter. If all that is good, and it still runs funny, start looking for vacuum leaks and other issues. The smog tube will make noise, but thats about it. Shmutz some jb weld or that magic high temp epoxy play-doh stuff on there to seal up the leak, or ditch it completely at his option.

[86VickyLX]

The check engine light will come on for only a few things. EGR being unhooked isn't one of them, but if the egr is hooked up and stuck open, it will light. Theres a few other things that will trip the light but its not that useful of a trouble indicator. As you've noticed, the car can run like crap and not give any lights.


Change the ECT and reset the computer, see what that does for it. Standard maintenence stuff is also important, plugs, wires, cap, rotor, fuel filter, air filter. If all that is good, and it still runs funny, start looking for vacuum leaks and other issues. The smog tube will make noise, but thats about it. Shmutz some jb weld or that magic high temp epoxy play-doh stuff on there to seal up the leak, or ditch it completely at his option.

I think it's been a while since it's had a tune up. There's some sort of procedure you have to go through for reseting the computer isn't there?

[91waggin]

I think it's been a while since it's had a tune up. There's some sort of procedure you have to go through for reseting the computer isn't there?

I believe you just have to unhook the battery for ten minutes or so....

[gadget73]

I believe you just have to unhook the battery for ten minutes or so....

thats the one. It actually doesn't need more than a couple minutes if you're impatient. If you feel inclined you can dance about on one foot while yelling strange things, but it won't do much but provide a possible youtube moment.

[86VickyLX]

If you feel inclined you can dance about on one foot while yelling strange things, but it won't do much but provide a possible youtube moment.