Extremely rich idle

[55trucker]

Try this......If you indeed do have a stuck open injector....run the engine at idle (you did say this problem is only at idle?) so the problem occurs.....shut the engine down and pull all the plugs. If there is only one (or more rich cylinder) the plugs should tell you which cylinders are rich. If they all are wet or fluffy black then the problems not necessarily injectors but is common to all cylinders and the rich situation is elsewhere as has been suggested above.

[cteepe09]

Hey it also could be you ecu chip is shot I race beretta's I played with different chips and found that some will make it run rich which is good if ya want more power? Also ck voltage on your tps sensor make sure it works right should be .5 at idle and 4.5 open wide open hope it helps

[robertisaar]

Hey it also could be you ecu chip is shot

if the chip stops functioning for any reason, you can't connect to the datastream. since weba was able to read us the BLM and INT, i'm going to say no.

[86FieroSEv6]

Does it have the correct PCV valve and how old is the oil? Also, a leaky EGR valve can do this.

[weba]

For the chip, I think I'm using the correct .bin file on it, 386211491108437882.bin ? Tho this is a California car (BAUB code) originally, hmm.. put it has passed the emission test in past years without issues on same .bin (i think) so it should not be chip related.

Condition of the PCV is unknown, it can be really old, at least 4 years. But could that really cause it run rich on idle? Oil has been changed every 3000 miles.

I am going to check that thing too if i can fit my hand in there... First thing i'm going to do later today is to swap the o2 sensor and try to see do i spot any changes... Then start pulling the plugs and continue to the plenum if i have to.

[IsaacHayes]

I don't see how a PCV valve could cause a rich condition. If the O2 is original then yes it will run rich even though the BLM's show it as not.

[weba]

I bought new PCV, spark plugs and wires today, swapping them in right now. >>
Old wires + plugs have 16.7k miles on them.

And working o2 sensor from my other car.

[Superdave]

o2 is ignored at idle, check the coolant temp sensor and look for leaking injectors.


injectors should be around 12 ohms and change the temp sensor that's right under the thermostat neck.

[3400-95-Modified]

o2 is ignored at idle, check the coolant temp sensor and look for leaking injectors.


injectors should be around 12 ohms and change the temp sensor that's right under the thermostat neck.

I already said that!!! But he said his ECM is reading the temp correctly... it was showing 198* which is not a bad reading... when they typically go you get like a -40 reading.

Its all coming back to a possible sticking injector.

[weba]

Okay i replaced plugs, wires and PCV with new ones, didn't see anything wrong in the old ones. Except the new plugs i got have number 44 on them and the old ones had 43, so they were one step colder.

Also replaced to other, known working O2 sensor.

BUT

I think that was all possibly for nothing?

I just compared the .bin file i used; BFUZ, It's for 92-94 J body 5 Speed 3.1.

It has 25649 bytes different than in the BAUB code what came stock in my 92 3.1 auto, so i re-flashed my chip with that. It sounds and feels different.

I think that has been the main issue over here, the code is just so different that it does not run perfect? But i have always thought it's the same engine physically, someone explain?


I think I'm going to try the emission test again with this setup, after raising the warm idle speed bit more, it's now 700rpm instead of 625 what it had on stock.. I may want to try 750-800 for smoothness...

If i fail emission test again, i will finally pull the intake and start measuring the injectors, how ever all the spark plugs looked perfect....

[IsaacHayes]

Auto will sound and feel different as it's calibrated for auto with the idle/etc stuff.

3.1mpfi 5spd bin is what you should run if you have the a manual on it...

maybe the spark plugs being colder was just enough for it to not burn completely?? But it does sound like it might be leaky injectors as everything else is ruled out.

[weba]

This site lists the chip BAUB to be 91.. and my car is 92. Hmmh? I may want to try 91 L-body manual trans .bin to it, but i cannot seem to find one.

Anyhow my car has passed previous years, but i seem to lost track about what ever bin file i have used back then Since i always swap it for the inspection.. doh.

Edit: what ever 91-92 files i compare, there are shitloads of differences.. interesting.. Anyhow i need to check my car's built date to make sure.

Also seems like there really are differences in J and L body same year .bin files.
BFUZ (92 J manual) has 23889 Bytes different than BAUP (92 L manual)

Seems like i have several choices about what .bin to use on inspection..

[IsaacHayes]

92/91 same damn engine/injectors. doesn't matter. Use the latest bin for a 3.1mpfi 5spd.

The J body manual bins may not have digital speedometer stuff... I think the later year ones did though.

[Superdave]

I would run BFUZ but compare the pinouts of a Jbody ECM with your own.



If you join up at v6z24.com there are pinouts in a sticky in the repair section for the '7730.

[weba]

I would run BFUZ but compare the pinouts of a Jbody ECM with your own.

BFUZ was the one i was running and i think it caused it to run rich @ idle.. Cause there was no sign of sticking injector since all the spark plugs looked perfect and clean and everything. So if it's not the binary code, I'm very confused what could cause it...