Lancia Dedra - Sometimes Spry, Sometimes Tired

Any correlation with ambient conditions (temperature, humidity etc)?

"Any correlation with ambient conditions (temperature, humidity etc)?"

No.

I know of a few people (myself included!) who have an intermittent problem related to the engine management system. The problem clears up (at least for a while) if the EMS is reset by disconnecting the battery for a few minutes.

Have you tried disconnecting/resetting when it's running "good"? How about when it's running "great"? Does a reset make any difference?

"Have you tried disconnecting/resetting when it's running "good"? How about when it's running "great"?"

Sorry, missed this comment. I'm don't know what EMS is. I assume the system "reboots" when I shut down. Do you mean disconnect the battery while the engine is running when it's running good/great?

The EMS - Engine Management System - is often called the "computer". You're right in that it does a sort of reboot when you shut down, but it's more like hibernating than a proper shut down/restart (to use PC terms). It needs the power off (i.e. battery disconnected) to do a full "reboot".

I don't mean disconnecting while running - turn the ignition off first.

This problem has persisted for almost the entire six years I've had the car. The battery has been disconnected quite a few times and replaced at least once. Having said that, certainly worth a try. Do think it would matter which "phase" I disconnected from - ok or great?

You'd need to try both to eliminate it as a possibility of having an effect - unless the first one you tried did something.

Ok, I'll give it a try - do I have to disconnect both terminals or is one enough? No problem to disconnect when Dedra is running just ok - when she is running great, I just want to keep driving...

Thanks, John. I'll report back, though I don't know how long it will take me to hit a "great" phase to facilitate disconnect.

In the meantime, any other ideas?

Michael

Positive terminal only is enough.

Know how you feel about not wanting to 'rock the boat' when she's running great.

'Fraid that's about it for ideas. Only other thought is that, as you say yourself, there are quite a few sensors scattered around, and if one of these was on the blink? ...

Good luck.

I don't have an answer but I had a similar situation with my old Nissan. When I start it up in the morning, it seems to run a little rough. When I stop for gas (switching off the engine) and continue my trip, the engine note changes and it seems to run a lot smoother, the engine doesn't seem to be laboring, it's just different.

Soon after, I discovered that if I started up and idled for about 3 minutes or so (just to get her warmed up), I switch it off for another three minutes and when I restart, she's great.

I've had her tuned, inspected, cleaned but nothing seemed to help. Overall, she was fine but, like you, I wished she would stay "great".

I've replaced her already so I don't have to wish anymore.

regards,

Vulcan

That sort of stuff doesn't help in my case - I've tried all sorts of starting/stopping drills, all to no avail. Many times the "great" phase is at morning startup - I can many times tell, somehow, as soon as I get ignition, even without pulling away.

I'm in no way a mechanic but, in light of all the symptoms, it seems to me to be some sort of electrics issue, which I know can be a slippery slope. The car, like most, I guess, from that time on, has got quite a few sensors and, she's Italian...

A VW Golf once had this symptom. The cause turned out to be a piece of plastic swarf lodged in one of the fuel pipes. It took an awful lot of expensive component-exchange maintenance and an awful lot of time to find it.

Yeah, that "...awful lot of expensive component-exchange maintenance and an awful lot of time..." is probably what's needed to get to the bottom of this, unless I luck out with John's suggestion. My mechanic, who used to have a Dedra himself (Turbo Integrale) fixed his current Saab by going through those hoops. He's just too busy and distracted to take the time necessary to do it right on my Dedra and I don't have the skills or access to the parts.

In lieu of all that, because he hasn't really experienced the noted phenomena himself, I think he doesn't quite take my relating of symptoms at face value and tends to think it's something to do with airflow intake, whereas it sounds electic to me. There is a sensor in the airflow intake hose/duct but it checks out ok when tested by computer...

I had a Volvo with a similar problem many years ago, it turned out to be a tiny spot of rust on the plain bearing of distributor.(the bearing that allows the advance and retard mechanism to move back and forth smoothly....)

This was causing the distributor not to properly advance and retard......don't ask me what was good and what was not, it was around 1984!!!

It took several months of searching to find......but once cleaned off and the bearing was properly lubricated the car ran brilliantly all the time....

I would liken it to a person who felt "off color" occasionally......

I had to completely disassemble the distributor, still possible in those days, but today?

You could also check for a leak in the vacuum pipe if cars (your car) still have them......or it will be in the EMS or the ignition sensor(s)......maybe!

IMHO, you have the provided a simple way to help solve the problem.

If there are no trouble codes showing up on the Dedra's computer, checking with a timing light would be a simple way to document the changes in the performances of the car.

With emissions as closely regulated as they are, changing fuel ratios are most likely limited to a narrow width. But changing ignition timing is not as drastic an emission change as mixture ratios are. And the changes the op describes sound to me to be the changes that I have come to find when advancing and retarding ignition timing. If the vehicle is equipped with variable valve timing (intake and/or exhaust valves), it could be that the valve timing could be sticking in the wrong mode at times. Checking this would be harder for the average person to check.

But if the OP has a timing light, he should be able to compare the timing between the two "modes".

If there is a difference between the timing setting between the two modes, It will then become a matter of finding what has caused the change. At least it would be a start.

Welcome to the insanity. Please read answer # 15 I really should have sent it to you. Sorry. Good luck.

Who was that for?

Both you and m n f.

Ok, still very open to more ideas, but in the meantime, thank you guys very much.

John, I disconnected the battery for a few minutes in the "ok" phase - no improvement. Still waiting for a "great" phase.

PWSLack, I don't even want to think about that...

Andy and Bob, I'm do for a service and I'm going to share these suggestions with my mechanic.

I'll keep ya'll posted. Again, the more ideas the better. Thanks again.

If you are "due" for a service, be careful.

It may do your car more good than it will "do" you!!!

I agree with Bob C, I had a bad knock sensor with the same symptoms, most likley caused by a change in ignition timing when it was not needed.

It looks like Bob C's idea is building up to critical mass. If we postulate that that is the "what," any thoughts on the "why" - what might be causing that change in ignition timing, bearing in mind that "Whichever phase Dedra is running in - ok or great - starts at ignition and is maintained at least until shut down and subsequent ignition - the phase never changes spontaneously while driving?"

Who, what, where, why, when?

If the timing is being changed, It would be because the ECM has seen something that it feels requires the engine to run in the "OK" mode.

Any of the more sophisticated code readers will you, or your mechanic to observe the parameters that the engine is operating in as it is running. That should allow you to see the specific sensor that is causing the mode switch. BUT, I believe that the bad sensor should show up as a trouble code. If so, you may have a basket full of codes. Please remember that you are looking for a cause, not the results.

Let me explain. If you have one of your injectors stick open, and allow fuel to spray into that cylinder continuously, there will be many codes stored. 1) low current at that injector. 2) That same cylinder will show as a misfire. 3) Cylinder bank #1 too rich. 4) ,Mixture control set too lean. There may be more also. The one stuck injector would cause all of the other codes as the system tried to correct an over rich condition in the one cylinder.

Please try to get a reading on the trouble codes first. Even if you have to buy a cheap code reader, it might be worth it. They should be available under $75. Good luck.

Good advice.

A short word of warning though, the "cheap" OBCD readers sometimes only read the first level, the standard codes, I have been told.

You need to make sure that the one you buy can also read the lower level codes as well, where the "detailed" infos are.....

I recently almost bought the wrong one too......saved before the bell went. In the end I did not buy one.

Find out how many levels are in the codes before buying, then test fully before parting with your money.....

...I've been holding back, afraid to trip the Evil Eye...

I was driving on Thursday night, as usual, in the "ok" phase. At some point, I hit ~3/4 pedal-accelerator. I know I said Dedra never switches phases spontaneously, only after shut down and re-ignition, but I had a bit of a twinge as I wrote that. That is, I knew it was true 99.9% of the time but I had a sense there was sometimes, very rarely, at least a partial change of phase after a heavy acceleration.

Anyway, there was no mistaking it this time - I definitely shifted into the "great" phase after that acceleration. I was tired and didn't really have the energy or faith to try a battery disconnect after I arrived home but I was packing the wrench and screwdriver so disconnected for a few minutes before going inside.

Next morning, Dedra started in "great" phase and has been, knock on wood, running that way ever since, so far. I'm flabbergasted.

I haven't been in for that service yet - don't worry, Andy, my mechanic is really an automatic transmission rebuilder - you can eat off the floor of his shop and he services Dedra out of knowledge and "love" (for the car) and has never gouged me.

I definitely buy in to your theory, bob c, that something is changing the timing inappropriately. I am amazed that your idea of "rebooting" the EMS, JohnDG, actually worked but I am assuming, as you intimated, that this blissful state will not last forever.

What do you guys think now? If and when this problem recurs, after my "revelation" at the beginning of this comment concerning rare change of phase without shutdown, are all theories still intact? When I "reboot," does that effect the individual sensors - perhaps the one residing in the airflow intake hose - or, if there is one, just the central EMS chip?

Let me take this opportunity to say that you all have been amazing. I have great respect and appreciation for you guys and am now regularly reading this classy forum.

Fingers crossed - touch wood & all that.

_{^{(I know it's superstitious clap-trap, but it really works! )}}

Whenever a vehicle is given WOT (wide open throttle), the engine computer knows that it must deliver full power. At that time fuel mixture will be programed for max power. timing will be correct for full power,If the valve timing is movable, it also will go to full power.

Do you regularly drive the dear Dedra at WOT? If not, try giving it WOT at a specific speed that is safe for you to do regularly. You should only have to hit WOT for 3-5 seconds. If you find a speed that will not cause violent actions from the car, you can use that as a diagnostic tool.

Once you are able to control when the changes take place, you can begin to determine what is causing the problem. Do you have a timing light? Have you located a code reader?

"Do you regularly drive the dear Dedra at WOT?" Ehhhh, what's regularly; a couple of times a week, once a day, all the time?... Way back in a much younger incarnation, I was doing WOT a lot of the time. Now that I'm older and mellower, let's just say I'm not averse to WOT when the need/urge arises. If I didn't have a profile like that, I probably wouldn't feel the difference between "ok" and "great."

"...try giving it WOT at a specific speed that is safe for you to do regularly. You should only have to hit WOT for 3-5 seconds. If you find a speed that will not cause violent actions from the car, you can use that as a diagnostic tool." Could you explain what you mean here, please.

As for the timing light and code reader, I'm going to do this with my mechanic - he's got 'em. I just haven't been to him yet because I have to move my office next week and I'm busy/distracted/freaked-out.

Note: more info about Dedra - I have the '97 Dedra LS (not as cited mistakenly in my first post,) 1800 cc 16V (VVT) 130 HP. Here's a link in Italian: http://www.omniauto.it/magazine/763/lancia-dedra and here's the Google translation of that page: http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&u=http://www.omniauto.it/magazine/763/lancia-dedra&sl=it&tl=en&history_state0=

"...try giving it WOT at a specific speed that is safe for you to do regularly. You should only have to hit WOT for 3-5 seconds. If you find a speed that will not cause violent actions from the car, you can use that as a diagnostic tool." Could you explain what you mean here, please.

I don't know weather you have an automatic, or a manual as shown in your pictures. The idea is to be able to hold the pedal down at least 3-5 seconds. If that is done in first gear, the engine is going to require shifting to the next gear. If done at ~1000rpm in third gear, there should be very little enough change in engine speed that shifting will not be needed, or occur if an automatic. And yet the vehicle speed should not be high enough to cause excessive speed on rural roads.

If you discover that you can bring dear Dedra from OK to Great on demand, we will have less things to troubleshoot. I for one would become suspicious of the throttle position sensor. But that should set a trouble code. I hope this helps.

PS. I had no idea what a Dedra was. But the pictures show a car that appears to be on a par with the likes of BMW, Audi, Jaguar and Mercedes Benz. And combined with Italian flair.It looks quite likable.

The EMS could be going into limp mode when the car runs "OK" and back in run mode (great phase).

Limp mode is when the EMS senses something is wrong and instead of taking all the sensors input it runs at a pre-set group of variables. When this happens the car will often keep running (better than nothing by design) but not run as well.

Have it scanned and see if a sensor or something else is bad, have it repaired, reset the EMS and see if this wasn't the problem.