3.1 engine ignition(?) problem

[michi]

Can someone see anything wrong at my datalogs? Should i replace the water temp sensor?

[3X00-Modified]

I'm sorry I didn't look yet, I will check them first thing tomorrow.

[themixer]

It appears you are having the same problem I did with my old 3.1 motor, the value for BLM is too low. It should be around 128.

When starting the car cold, the system will be in open loop. Watch your BLM values, they should be at starting somewhere around 128. As the engine warms it will kick into closed loop that's when I noticed my BLM values starting to fall, smelly exhaust, and sputtering. With the Tech1 scan tool I was able to reset the values, but as the computer adjusts for the fuel issue, the number kept falling.

I made a video of it
https://www.youtube.com/watch?v=SAVEK89f4EE

start with checking the injectors out, one/two may be stuck open and dumping fuel into the motor!

[3X00-Modified]

I cant open xdl files... any chance getting those logs in CSV or XLS files? Looking at that snapshot though your coolant temp sensor appears to be working as it should. Does the Intake temp of 93 sound correct to you? Was the car just sitting there and idling? which would make the bay warm enough to read that. Also do you see the O2 sensor reading bounce between a very low 100-80 number up to 900? Or does it just hang in one spot?

[1988GTU]

What does the fuelp pump volts do when driving around and then doing WOT runs. Do a cold initial then up to operating temp of that, then report back.

[michi]

Car was idling when engine was warmed up and O2 is reading 480 to around 530 there. And when driving around engine warmed up O2 reads up to over 900.
I was thinking injectors too so i got them cleaned and looked if they work when i put power on them. Too bad i couldnt check how good they are spraying gas when installed.
I am just not sure about if its a injector or not because somethimes its running better and got power...

I will take a bigger datalog this weekend of my car driving around and doing some WOTs when engine is cold and warm also some idling. And i will see if i can record in csv or xls... havent checked that out yet with tunerproRT.

Also... i noticed my car got no power in high rpm. Last time i floored it in third gear and after 5krpm it was BEARLY getting faster, could already feel that its loosing power after 4500. I mean yes its not a high reeving engine but no power at all after 5k rpm?
I testdrove a 3.1 beretta some years ago and i reeved it up to 5500-5800 in 1-3 gear pretty easy and couldnt feel a loss of power there.
Pretty sure its because its running way too rich but thought im telling you guys anyway
Had this once on my old Quad4 and there it was a O2 sensor failture as well... but cant remember if it was threwing a code or not. Think i should get a O2 sensor and just test it out.

[3X00-Modified]

I thought you had done the O2 already but I see you replaced it 2 yrs ago... and seeing how it's reading appropriately, Over 900 when your driving when it is rich then I don't think it's the cause of the issue. Stock 3.1L injectors are notorious for failing so I think even though you got your's cleaned it's time to find a set that you can swap in to see if it makes things better. There isn't much else that can cause a rich condition like this other than a stuck injector... It definitely does not seem to be sensor related. If your Fuel trims BLM's were in the opposite direction and high then yes I would point at maybe the O2 since it would be sending a low reading and the ECU would be over compensating... However you have the opposite issue. It's reading really high/rich and the BLM's are low meaning it's trying to trim fuel so there has to be some sort of fuel leak allowing excess fuel into the system when it shouldn't be getting in.

[themixer]

https://www.youtube.com/watch?v=rUUgR94drxg

you could try something like this on them to see what kind of spray pattern you are getting and clean them at the same time.

I spent a lot of money attempting to find 3.1 injectors that were in good working shape, tried ebay auto parts stores, even had a chip burned to run 3100 injectors but never had any luck.

In the end I switched engines to a 3400, and it runs better and cost way way less money than I spent messing around with the 3.1.

Seeing the location you are in it's probably not so easy to find 3400 motors. If you could find a set of multec 2 injectors out of one and the connectors/injector harness, you could get a chip burned to run them in your 3.1.

If I could go back in time that's what i should have done to my own car.

[SuperLbody]

Looking at the snap shot of data, it's kind of tough to diagnose. I don't like how low the MAP is reading but that could be due to elevation. Check for any restriction in your intake and if your losing power in the upper range, check out your catalytic converter. I'd also get your fuel pressure checked out just to rule out injectors.

[3X00-Modified]

https://www.youtube.com/watch?v=rUUgR94drxg

you could try something like this on them to see what kind of spray pattern you are getting and clean them at the same time.

I spent a lot of money attempting to find 3.1 injectors that were in good working shape, tried ebay auto parts stores, even had a chip burned to run 3100 injectors but never had any luck.

In the end I switched engines to a 3400, and it runs better and cost way way less money than I spent messing around with the 3.1.

Seeing the location you are in it's probably not so easy to find 3400 motors. If you could find a set of multec 2 injectors out of one and the connectors/injector harness, you could get a chip burned to run them in your 3.1.

If I could go back in time that's what i should have done to my own car.

Funny thing about that... I just grabbed an old set of 3100 injectors I had and slapped them into my Indy... Ran great going all the way to Tenn Bfest Never touched the chip.

[ifixalot]

If my memory is correct. The injectors in the 3.3 liter Buick Century V-6 are the same as the 88-90 Beretta 3.1.
Those cars were pretty common in the junkyard. And it is easy to get those off the engine. You don't have to pull the manifold. I got a bunch one day as spares.
If you have a leaky injector wouldn't lose fuel pressure after you turn the key/engine off?
I know my throttle body mini van loses pressure but in that case it is normal.
My 96 holds pressure. If I want to work on it, I have to bleed off thew pressure into a rag.
So if your is supposed to hold pressure and it does not, you have a leaky injector.

[michi]

Too bad i dont have a fitting for the fuel rail to check fuel pressure. Actually i was looking around for a chevy(olds) alero with a 3400 some days ago and found an awesome deal just about 20km away from me. I was looking around for like 3 years already and didnt found a good deal so some months ago i decided just to keep the 3.1 engine cause i didnt wanted to have another expensive project but right now i am waiting for some details about the engine and if they are good im probably looking at the engine to see how its running and buy the car.

If this fails im going to order a fitting, get my fuel pressure tested and order some new injectors and keep rockin the 3.1 engine.

[Rettax3]

Stepping into this kind of sideways -sorry if this has already been addressed before -but just to mention a bad FPR can cause high pressure at the rails, and excessive fuel flow thus leading to the rich condition despite negative fuel-trims. ifixalot -good point on the leaking injector bleeding fuel pressure down. But pressure can also bleed down from a faulty FPR or a bad anti-flowback valve in the fuel pump, as well as the obvious external leak which would be noticeable by the smell of gasoline.

OP, have you tried the propane method for testing the O2 sensor? There is another way of testing it, I can't think of it off the top of my head.. The sensor is probably good, but not conclusively so from what I have read...

Again sorry if this isn't helpful, I just skimmed through the last couple of pages...

Why doesn't your fuel-rail have a test port?? All port-fueled 60-degree V-6s I've seen do have them. Regardless, get a loan-out pressure tester from Autozone or O'Reillys and use the splice-in "T" fitting to test your pressure -just be sure to have a line-splice to fix your fuel line afterward (or put a permanent "T" in place so you can check it again in the future...

Edit: Oh, Austria. Sorry.

[michi]

Yes i am from austria and the fuel pressure tester my buddy got dont fit on these cars. I could find a us car repair shop but have to drive a few 100km to arrive to one. Also i replaced the FPR.

[3X00-Modified]

I will say replacing the whole engine is a waste of time, you have a fueling issue which is 100% electronic controlled... So you have a bad sensor, or bad injector or something up with the harness. I'd exhaust those options first.