3.1 engine ignition(?) problem

[michi]

Hey guys, i guess i got a ignition problem in my beretta... i heard the engine is running kinda rough, especially hear it at idle so and i also failed emissions test. I replaced sparkplugs, wires and coils maybe 2 years ago. Also got all sparkplugs out and looked if they get a good spark or not, everything seems to be fine.Since i have a spark on every spark plug i wonder where the problem could be... i thought about the ignition modul but i cant test it yet. It also got the power but it kinda smells at idle when the engine is hot.
I also feel little fuel or ignition cuts when i cruise down the road at low rpms and as i said, especially in idle at 800 or 900rpms.

Any suggestions?

[Money pit Beretta]

My guess would be fuel pressure regulator. Those are one the few problems that 3.1's have. Because it is under the upper intake I would also replace the PCV hose. They tend to rot out over time.
Then there is the crank sensor, that could be going out too.

Damn long weekends! I'm ultra tired.

[1988GTU]

If the coils ohm out good and dont have any cracks/rust bleeding from it, then I'd wager the ICM acting a fool or the wires are in need of replacement.

[michi]

Thanks guys, i will take care of these things and hope anyone of these will help. Sounds weird but you guys know whats the clicking sound when i hit the throttle (at the throttlebody itself). It always does it just once when i give it a rev.
Also when im driving and the engine is cold and i give it a full throttle its stuttering for like a second or so.. feels like a fuel cut, just like the speed governor(lol) and then it goes. When engine is warm its never like this.
I think this thing needs a tune up badly. Its not running that smooth in idle either but like already mention'd.. it still got all the power and doesnt act like it would run on 5 cylinders.

[1988GTU]

Sounds weird but you guys know whats the clicking sound when i hit the throttle (at the throttlebody itself). It always does it just once when i give it a rev.

Sticking IAC or injector pintle.

[Money pit Beretta]

Steam clean or Sea Foam(best choice) just to make sure it's not carbon/blow by build up. When you baby an older engine things start building up. A good clean may save the tune up for a later date.

[ronaconda]

I second the IAC. Wouldn't hurt to check the FPR too.

[michi]

I checked the IAC and swapped it out two times with different ones but i still hear that ticking sound when i hit the throttle pretty fast. I checked all sparkplugs... they were a bit black but didnt looked that bad... i am sure it runs on all cylinders but i noticed that my exhaust is getting pretty hot... even my exhaust tip gets hot after some miles. Weird thing is it doesnt smells like gas or something or runs lean since all sparkplugs didnt looked like the engine would run lean. Also there is no check engine light. But i am going to get my laptop connected to the ecm and look if i see anything wrong there.
I bought some engine clean product... its not seafoam because i cant get this here but i heard good things about this product too.
I am going to check the ignition coils again and the FPR and see if it gets any better but maybe you know why my exhaust is getting hot? I pretty much keep it in low rpms but i am worried that it will kill my catalyst when my exhaust is getting that hot.

[ronaconda]

Cats do their job in the thousands of degrees. And your exhaust all the way out to the tip will be hot. Even though your CEL isn't on, check for codes. The light can come on and turn off possibly without you noticing but will still store a code. If you think the fuel mixture is off, change the O2 sensor. Find a junkyard PCM and swap it to make sure you aren't fighting a bad PCM too.

[michi]

Yeah, the fun part is that the rubber hose from the emission tester was melted together after they did the test, lol. Thats why i was wondered why the exhaust gets so hot... never happend that to me before. Going to check the O2 too... i repleced this one 2 years ago but i think i have a spare one i could swap in.
Thanks!

edit:
just connected to the ecm with my laptop and checked for codes - none! If anyone could look over my datalog to see if thers anything wrong id be very happy.

[Money pit Beretta]

Clogged cat or muffler?

[ifixalot]

I'm guessing this is a late 80s or early 90s car.
The fuel injectors on these were not reliable.
It could be a bad fuel injector. One not opening will cause a lean condition,
the computer will richen the other cylinders up to compensate. Then your cat
will have to work harder to burn off the fuel and get hot.
I had a bad injector on a 92 Buick. 5 plugs were black one looked white.
The injector that was bad had a resistance of only 4 ohms, the others 11-12 ohms.
Did you plugs all look identical? If you have an ohm meter, you can check the electrical connectors
for the injectors resistance. My car had a bumpy idle because that one cylinder was lean
and would not fire. Even after I changed the injector though, it would not idle very smooth.
I think that was because it had been like that so long, the valves were perhaps, screwed up.
The ticking might be pre-ignition of the five cylinders which may have heavy carbon build up
from running rich. Carbon can get hot and cause pre-ignition.

[michi]

This thing is making me crazy... i replaced all 3 coil-packs today and started it up and noticed it runs just fine now and idles so much smoother. I thought "YES! now i can pass emission test next week".
Well... after some miles of driving home from garage i noticed it runs just like before i swapped the coils out... when i rev it i hear how its not running on all cylinders and in idle i feel it just by the exhaust gases.

I would replace the complete ignition system again but of course i SHOULD pass emissions test within the next two weeks so i am in kind of hurry to get this thing running.

[1988GTU]

you didnt check the icm?

[whiteretta]

Take the ICM off and take it to your local parts store so they can test it. Make sure they run the test multiple times so it gets nice and hot; that's when they usually fail.