Technical Stilo 2004, 1.8 16V loss of throttle

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Technical Stilo 2004, 1.8 16V loss of throttle

EvilDragon

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Hello everyone!

Sadly I'm another one of the unlucky guys driving a Stilo with what seems to be an abundance of electrical issues... Even though it has a relatively low mileage for its date of production (currently at 177k km), it seems previous owners didn't take a lot of care of it, and it's all starting to break over my back :(

So, to begin. I've already gotten myself used to the "Engine Fault" error - initially it started blinking that when there wasn't a sufficient amount of oil (and boy, does this one slurp the oil like it's nothing! I usually need to fill a liter or two every one or two months - and no, it's not leaking anywhere!)...

What's started to annoy me later was the ASR/ESP errors. Seemingly out of nowhere. Sometimes it would drive just fine without those erros, other days it would just pop them out in the middle of driving, often accompanied with a "burp" as if the brake was mildly pressed then quickly released.

But as of more recently, the issues started becoming more severe - all of those same errors pop up, but now accompanied by (not always, but often) loss of revs and throttle pedal completely cut off. Then when I put the car into neutral gear (driving a 5-gear stick here, not automatic), it is stuck at 2000 RPM, when I know it's normal to have it around 700-900. So that alone is a cause for concern. Sometimes it starts doing this as soon as I start the car - it's in neutral, but the car goes straight to 2K RPM. Then I need to turn it off and on several times and pray it will work on regular revs.

BUT THEN, it can start doing the same thing in the middle of driving again. So I have to pull over (quite annoying when driving through the city, lots of pissed off drivers around me, etc.), turn it off, turn it on, pray that it works, or rinse&repeat. Sometimes, just sometimes, it would pop up an additional "Car Security Fault", but that's rare.

I went to the electrician for diagnosis, and what was written there was "intermittent CAN network error" regarding ASR/ESP fault, and something about catalyst (also intermittent) regarding engine fault. However, the catalyst is fine, the car passes all the "green" tests when we went to renew our car registration this July.

What that electrician dude suggested was trying to clean each and every electrical contact for the CAN network. Which I understand might be a pretty arduous task (hence expensive), and is not guaranteed to fix the issues.


This all smells to me like sensors spitting out nonsense - might be the very warm weather, but I've had ASR/ESP/engine faults even in winter... Or could this be related to throttle actuator or something (not sure if this is the correct term in English)?


Any thoughts are welcome. I can try and find out more info as well.


Oh yeah one more thing. Sometimes when I turn the car on, it doesn't even rev up enough and just goes down to 0 RPM and dies on me, which an occasional "low oil pressure" message. But I checked the oil and it does seem fine to me. Could something be wrong with the oil pump, or the alternator, or the starter (heh, or ANY of the million things that could go wrong with a Fiat? :D)? Also... unfortunately I'm not one of the guys that will get his hands dirty and go too much under the hood, unless it's something REALLY simple and followed through via images... Thanks for understanding!


Much appreciated for any comments! :worship:
 
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How healthy / new is your battery? Sounds like classic low voltage issues to me.

If you battery is old or an unknown (i.e. you dont know how old it is - you can check you paperwork / history) then i suggest replacing the battery.

Make sure all the battery clamps and terminals are nice and clean and check the earth strap for the battery to make sure contacts at both ends are good, clean and rust free.

Ben
 
Hello!


Thanks for your suggestion. I am absolutely clueless about the state of the battery. It definitely wasn't changed since we purchased the car (which was roughly 9 or so months ago). Supposedly the battery was replaced several months before we got the car, but I should probably never ever trust previous car owners. :)

We'll check the battery and go from there. Will report back with more info when that's done.


Today, for example, we had no issues and I started the car like 4 or 5 times (went to shopping). However today is also 10 °C less outside (compared to yesterday's 38°C). I guess this could influence the battery. I'm still stumped at the car flat out not starting (in previous week) even though it revved up. It'd just go back to 0 RPM and turn off. That could also point to the alternator being worn out, perhaps?
 
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I also have a 1.8 16v Stilo. I used the have those similar simptons.

What i did:
-Cleaned all the the ecu contacts with electronic contact cleaner.
-The earths (specially the one on the transmission) and the one bellow the battery.
-Replaced the battery.
-Cleaned the whole fusebox with the guide in the guides menu.
-Cleaned the throttlebody.

After doing all of this do a throttlebody relearn, by keeping the car with the battery disconnected about an hour or two, then start the car and let it iddle for about 15 minutes without touching the gas pedal.

When the rpms are stuck at 2k and the throttle won't respond is because the ecu is not able to communicate with the throttle actuator/sensor and it doesnt know the position of it, so it gets in "limp mode" stucking the rpms to 2k so the car won't stall and you could get the car to garage for inspection.

1.8's usually have problems with the throttlebodys, so don't get dissapointed. Besides that is a really good engine.

Maybe i did some typos here, english is not my native language. Sorry for that, tried my best.
 
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That is some GREAT info (and your English is fine)!

So, you didn't need to replace the throttle body, just cleaned it? That is good to know, I see it's a pretty expensive part.


I will take all this info to my mechanic. Much obliged!


1.8's usually have problems with the throttlebodys, so don't get dissapointed. Besides that is a really good engine.

Ehehe. If a bit hungry on petrol! Mine slurps 8-9 liters/100 km no matter how I drive it. And oil consumption is ridiculous.

But damn, it sounds really furious when I push it to switch gears at 3.5/4k rather than the usual 3k :)
 
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With the throttle body i alse went a step further and openned the whole throttle body by removing the black cover to clean everything in there and lube it. :)

And oil consumption is ridiculous.

Hahaha, forgot to mention oil comsuption. I'm right now clean the engine with SeaFoam and ATF (automatic transmission fluid) to remove any sludge build up that there could be inside and then an oil change. Imma throw a 20w50 in there and also add Restore Oil additive which is supossed to increase compression. Also purchased a compression tool to verify if it really increases. *fingers crossed*

Also a quick question since you also have an 1.8. When you remove the oil cap with the car turned on, do you have blow-by, because mine is kinda blowing some oil fumes out. I have a theory about the oil comsuption of this engines which is that the blow-by scape system (PCV) is not suficcient enough to remove the positive pressure and that pressure will make oil go through the rings and burn the oil.
That's just a theory that i have. Planning on putting a second breather on the valve cover. XD
 
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Also a quick question since you also have an 1.8. When you remove the oil cap with the car turned on, do you have blow-by, because mine is kinda blowing some oil fumes out. I have a theory about the oil comsuption of this engines which is that the blow-by scape system (PCV) is not suficcient enough to remove the positive pressure and that pressure will make oil go through the rings and burn the oil.
That's just a theory that i have. Planning on putting a second breather on the valve cover. XD

Hmmm, I will report that. I suppose I should do that after the engine has been running for some time?

I remember, when I was checking the oil level right after turning the car off, after I pulled out the oil check stick, I did get some fumes from that pipe (but this is, as you know, NOT the same pipe through which you add oil into the car). So your theory might well be right, I guess?
 
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By the way, can you tell me what relation do ASR/ESP errors have (which are, as I understand, part of suspension/braking system, not engine) to the suspected throttle body issue? Or is this possibly a separate electrical issue (which is why you cleaned ECU and fusebox contacts)?
 
By the way, can you tell me what relation do ASR/ESP errors have (which are, as I understand, part of suspension/braking system, not engine) to the suspected throttle body issue? Or is this possibly a separate electrical issue (which is why you cleaned ECU and fusebox contacts)?

On some cars (don't know fiat stilo specifically) when the brake pads are about to go down they give the same error about the ASR, which is basically traction control. You may ask your mechanic to check how much life your break pads have left.

Also make sure you use electronic contact cleaner on the connectors under the engine fuse box (D4 i think they are called). That jobs you could actually do it your self, just get the cleaner disconnect those plugs and spray them with the contact cleaner also spray below the the fuse box, and let everything dry.
 
OK, some time has passed, but I have something to report!


The engine fault issue has been resolved! It was not the battery, it was not the throttle body. Throttle potentiometer was working just fine, but the connector to which it connected had some slightly bent pins on the receiving end (and probably some grime, too), and this randomly messed up the data that was sent to the ECU.

Issue located by electrician in like 10 minutes, fixed immeediately after popping the engine cover, and no charge taken (because electrician said he can't guarantee it'll 100% work forever, and that I should report how it behaves to him).

ASR/ESP fault still present though, not always. It seems to only happen when I am decellerating out of gear and pushing the brake solidly. I should probably take it to the mechanic to check the brake pads, I assume?


Thanks for ideas, everyone. Glad to be able to start the car up without any beeps from the ECU!
 
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