Stumbling right under 2 RPMs

[Dibly74]

Hi, I've been reading this forum for awhile but this is my first post. This place has been very helpful diagnosing and fixing problems on my two Lincolns.

Now for the current problem.
When my cars RPM's and right under 2 it starts to stumble like its looking for the next gear. It occurs most of the time no matter drive or overdrive as long as my RPM's are right under 2. As soon as it goes over two it quits. I've found one post that describes my problem exactly. http://www.lincolnsonline.com/forum/showthread.php?t=38171
In the last six months the EGR valve, EGR vaccum pressure regulator, EGR backpressure transducer, EGR tube, and a couple vaccum lines have been replaced.

I was wondering if an EGR valve can go bad that quick because nothing happens when its in park and I unplug the vaccum line from it. When its unplugged it also dosen't seem to stumble or at least that bad. Also when the EGR valve was changed the passage was only partially cleaned out, but nothing that would seem to restrict flow. Also one of the bolt holes to the intake manifold from the EGR valve has been stripped but it seems to be seating fine.

Im not sure how strong the vaccum should be at idle but it hardly seemd to be sucking from the hose that goes to the EGR valve. The only thing thats connected to the vaccum that I havent changed but the internal filter for it seemed pretty brown was the Air Injection Reaction solenoid that has a red hose and a tannish hose attached to it. i was wondering if that could be restricting flow or affect it in any way.

The car is a 1995 with 135,000 miles on it. If anybody has any suggestions or ideas on this please let me know, its got to be the most annoying thing I've ever had a car do. Thanks.

[pro-five-oh]

Welcome. I would clean (or replace) the IAC valve (tech article) first and see if it helps. Also run a code scanner on the engine. A bad EGR valve position sensor code could come up.

Hey guys, could the bad vacuum line from the PCV valve to intake cause this?

[Dibly74]

Oh yeh, I forogt to mention that the IAC valve is only a few months old also and the PVC valve and vacuum hoses are only about a week old. Maybe the fuel vapor solenoid and EGR position sensor in conjunction causing this. I think this weekend I will replace the EGR valve, EGR valce position sensor, and the feul vapor solenoid which I replaced about 3 years ago, twice within one month. Let me know if any of this helps.

[Dibly74]

Some good news.... Sorta.
I found an air leak in the `NEW` EGR tube at the base or the REF tube. I know this defineatly has something to do with it but I don't want to spend the money on a new one just yet.
I put some JB Quick weld on it and hope that helps. It sayd it can withstand temps of 300 degrees. Does anybody know how hot and EGR tube gets or even an exhaust manifold. Any information would be greatly appreciated.

[Dibly74]

Well. The JB quick weld didn't hold. It turned to powder and fell off. So I bought some stuff from discount auto called thermosteel says it withstand 2400 degrees. But its a pain to apply and cure. Im going to try this tomorrow because I can't stand it running like crap. Also the car gave and O2 sensor code saying its picking up a lean mixture in the exhaust. could this be from the bad EGF flow from a cracked tube? All four O2 sensor are about 8 months old and are Bosch brand. Im hoping fixing the tube will fix that problem also. If anybody knows if that will cause it let me know.

[Steve Moran]

Have you used any thing to seal gaskets lately? If so was it O2 sensor safe?
Antifreeze in the exhaust will do it, so will oil burning.

[Dibly74]

No, I haven't sealed any gaskets, and it dosen't burn any oil. The coolant level never goes down so its not losing any collant in the exhaust. The only thing I did was use seafoam about 2 weeks ago. I thought seafoam was O2 sensor safe. But do you think that it getting a low amount of EGR flow would cause an O2 sensor to pick up a lean signal.

[Dibly74]

Im pissed. I was using sandpaper to clean the EGR tube and it broke in half! Its only about 11 months old from Ford. My old one wasn't even broken I had to change it because it fused to the old EGR valve. I don't know if anybody has ever taken an EGR tube off of a 95 Continental but it is the least fun thing I have ever done. Im not going to drive it the way it is so im gonna have to retire it for a couple of weeks till payday. Guess im just gonna have to drive my 89 Towncar for a while again.

[Sean Mintz]

I have noticed a similar effect on my 97 continental. When accelerating non-aggressively (ie, keeping it under 1500 rpm), I can sometimes feel the car almost shudder. It disappears when I stop accelerating and the rpm levels off at 1100~ish rpm. I think I need ot take the car to the actual Lincoln dealership this time (I have to get a headlight replaced, see another thread). I'm going to mention this and see what they say. I'll report back.

Sean

[Sean Mintz]

I mentioned this at the dealership. They had diagnosed my car with low compression a while back, but considering the small amount of miles I drive and the potential costs, we decided not to do anything about it. They thought this had to do with the low compression.

Sean

[Dibly74]

A dealership will tell you anything to make you pay big bucks. This didn't start till I got a leak in the EGR tube, on the REF port side too. So the computer was picking up the HI side of the backpressure transducer but not the REF port. When I JB quick welded it, it would hold for a couple of days and in those couple of days the car would start up fine and not stumble. If it was low compression I think it would happen all of the time not just in that small RPM range when the computer tell the engine to rely heavily on EGR flow. When I unplugged the pressure sensor even when it was leaking the car would act normal because the computer was picking up one steady low output from both sides of the sensor and not just high from one and mid-range for another. One my first post in this thread I left a link to an older thread when a guy had the EXACT same problem and it said what all he did (very detailed too) to fix the problem. I would highly doubt low compression on these engines, because i've seen some of them take a beating and never have a problem, and i've seen some be pampered and just turn to crap.

Another thing about the dealership, I brought my car in for air suspension work because it was sitting on the ground. The quoted me a little over 500 and I said just fix it. When I got there to pick the car up I haven't even walked in yet and I saw it in the lot and it was sitting on the ground still. I had to pay in and then they quoted me about 2 grand more and said they had replaced all of the harnesses to my air solenoid valves. Why I don't know. They were fine. All that was wrong was the compressor lost the ability to vent air and sent it into a default mode. I have since replaced all 4 air bags with lifetime bags and the compressor and it hasen't given me a problem in well over a year. Since i've go the car I have put more than 5 thousand in the suspension just so I can keep the air ride and not have springs like every other car on the road.

Still waiting on the 22 mm wrench from friends to be able to pull the EGR tube and weld the pipe back on. When I get this done I will post if it fixed my problem for me.

[Dibly74]

CRAP! I finally got the crowfoot wrench set that I wordered that went up to 22mm like the book said I needed. I got under the car and tried to put it on and it woulden't fit. Thanks you ford. I measured the cresent wrench that for on it and it was a 27mm. Thats huge for a crowfoot, what it HAS to be to get it off. So I ordered a jumbo set which wasn't cheap even for a knockoff brand. I got it in and it came off with no problem after that. We welded it back together, reinstalled all the parts and took it off the wheel stand that it has been sitting on for more than a month. Started up and it did its usual THUMP THUMP THUMP that it does right what its stared un when its cold and then ran fine. By the way can anybody tell me whats bad in the engine to cause that. I know its from oil not getting to the camshaft fast enough. But what part exactly is it. Anyway it got it warm and then took it out on the highway and exactly the same right under 2 rpms it stumbled and jerked like it had been. The only thing that I havent replaced that the guy said he changed that had this problem is the feul vapor canister. Does anybody know how I can test it before I buy a new one for more than 100$.

[Dibly74]

Finally. My problem seems solved. I replaced all 4 O2 sensors today which was under warranty. I got the dealership to order me the feul canister purge valve which was discontinued and was the only one left in the state. I also found when I pulled it off that one of the vacuum lines had stretched quite a bit and was allowing it to leak a little bit. I replaced it with a smaller hose and stretched the ends and forced it on. When I drove the car it stumbled for a couple of miles them seemed to go away. Im guessing that the PCM had to reconfigure itself for the added feul vapors. Kind of seemed to idle slightly better. Now all I need to do is replace the oil filter adaper o-rings, which means draining the oil, coolant, and freon. Removing and AC compressor, a motor mount and the thermostat housing, and them the oil filter adaper housing. Sounds like a pain in the ass. Has anybody here ever had to get these replaced before. If so let me know how easy it was to remove the motor mount, because one of them bolts looked hard to get to.

[Dibly74]

Ok. I was wrong, today the car started doing the same thing and gave me the CEL again. I got it scanned and its the same lean code on bank 2. I just replaced all the oxygen sensors, EGR valve, EGR position sensor, EGR backpressure sensor, and feul canister purge valve. Can ANYBODY tell me their thoughts and why it would still be giving a lean code. The car also has horrible pickup, maybe a catalytis convertor? Any insight would help.

[v8_dave]

Aww man, I hate seeing all this money invested and no deffinite results. Grrrr :mad:

I wish I could help but I have no ideas. Only thing I can think of is one of those OBD2 code readers that hooks up to your laptop while driving and does realtime evaluation of the vehicle...spark and fuel and everything.

WOT is crappy too? It cant be a transmission or Torque Converter you think? :confused:

These cars seem like 100K mile throwaway vehicles from everything I hear about them.

[Dibly74]

Ok, I got factory spark plugs and a factory PCV valve. Im gonna take off the platinum 4 plugs that I put on about 3 years ago. The dealer also told me today that the lean code could be a vacuum leak and spray carb cleaner on the hoses to see if the engine stumbles. I attempted to take off my rear catalytic convertor. I got all the bolts and brackets off no problem but I didn't have a tourch to heat the pipe and pull the other end out. That things is in there. I used a solid metal hammer and whacked the begesus out of it as hard as I could and it barely moved. I tried this for abut an hour and then gave up. I guess Im gonna order a new one for the rear and not mess with the other two, might try to clean them out, not sure yet because they are a pain in the ass to get off. Found a fairly priced OEM converter on E-Bay I guess I'll buy. I don't want to reuse the old one even if I cleaned it out cause all the wacking the begesus out of it bent the crap out of the hangers and the converter. But while wacking it I found where a rattling noise comes from when I start the car. Guess one of the screens is comming apart. So anyway, off to spend more money on the converter. I will post how it goes after I put it all back together with a new converter and plugs I think the sentimental value of this car is what keeps me living from paycheck to paycheck....

[v8_dave]

Good luck! Listen for hissing too from the a vac leak. Have someone else shut the car off and listen when the car is off but still sucking vaccum. They become real noticible then.

[Dibly74]

You know I've heard a quick hiss when I turned the car off a couple of times but never thought about it. I think its comming from the large vacuum line off the intake manifold to the firewall port. I think its leaking on the firewall side, thats also the port I pulled off to seafoam the car a couple of months ago. Although it only did it on ocassion, maybe 5 times. Even though it dosen't hiss when you turn it off it can still be leaking at idle speed right? Oh yeh, just ordered the catalytic converter. Specifically wanted an OEM so I could bolt it on and not have to do any special modification. Also has the muffler hanger bars so that it wont jump around everytime I hit a bump. It cost $165 with shipping. Can someone tell me if thats a good price for an OEM converter with gasket.

[v8_dave]

Got an idea! Pull the harness connctor on the MAF to disconnect it. The engine should run rough, then smooth out. If it drives better with the MAF disconnected, you know you have a bad MAF or a huge vac leak. If it drives much worse, then you have a bad TPS. If it just drives alittle worse, then the MAF, TPS, and vac leaks are fine.

[Dibly74]

Good idea. I'll try it when I get the new convertor, plugs, and pcv valve put on. But the MAF and TPS are amongst a number of new sensors. The only original sensors are the knock sensors, camshaft sensor, and engine temp sensor. They shipped my convertor today and im not gonan take it off the wheel stands till I get the new one on it. Not really to angry about spending so much on the car because I like it so much. Probally next payday I will order new leather seats in my style and color from a guy parting one out, which will cost more to get it to me than the price of the seats.

[v8_dave]

Im glad you like your car so much. I mainly said do that because it is a great way to check for vacuum leaks.

Did you look in the converter and it looked free and clear?

Im commited to helping you resolve this. :)

[Dibly74]

Well first off let me say that I took the extreme pleasure of replacing my rear catalytic converter yesterday and when I got it off I beat it on the ground and nothing came out of it and the only part that was black or just really darker colored was the center where the exhaust directly went through it. I went to change the spark plugs today and tropical storm Ernesto said I coulden't. But I don't think the converter was the problem being so clean. which this is the third inline of three converters. Im not so sure that there was a vacuum leak cause when I started it I sprayed throttle body cleaner on all the hoses any nothing happened. That is what the dealership told me to do. What is everybodys opinions about the lean code and what can cause it. The car has very bad accerleration, idles slightly off, and is giving the code on bank two which runs through all three converters. Can anybody tell me what all can cause this code repeatadly after clearing the codes and can driving it while its running lean hurt it. Please send your opinions.

[v8_dave]

Pull the MAF harness dude. Its so damn easy I want to see what happens/driveability like this. I'm thinking more of an injector now but that is a guess. I want to see what happens with the MAF pulled, it wont hurt anything. Just drive alittle with it off, it resorts to a factory rich mixture using the TPS to decide on fuel regulation. :)

[Dibly74]

Sure thing, I will try it as soon as this tropical storm has passed. The car in on dead empty, 0 miles to empty and with the massive amount of old people and doomsday people during this the lines took me forever to get gas yesterday in the towncar. It probally has JUST enough to make it ot the gas station. I will try this as soon as this is all over. I really miss driving the car. Will let you know how it goes.

[Dibly74]

Well I thought I would post a little update.I put the new Ford spark plugs and PCV valve in it. I also just ordered some low mile injectors for it, and I am trying to get all the factory Catalytic convertors from a guy I bought parts from before. Im just not happy with the one that is on it and it also wasn't the problem. Its to restrictive compared to the stock one. I thought about something that might have clogged the front ones. Awhile back I was cleaning the throttle body and used regular throttle body cleaner, but I left it on the car and ran more than a half of can through the motor. It put out lots of black smoke and for some reason I thought it was good at the time. Also later after that is when thecode came up for an O2 sensor, then the bank two problem. So I figured I will just replace all the catalytic convertors. Especially since they are only a couple of years old to that car and were Ford replacements. I was wondering if throttle body cleaner will clog up a convertor.

[v8_dave]

Still too bad. I wouldnt think they could clog up just like that. There doesnt seem to be anything left to replace! Keep on it!