I have a problem that no one can seem to figure out!!

[Scoobum]

I had an 02 sensor go south on me once. Car would drive normally for a while...and then get a miss in it...then drive normal...and on and on. Did it for a couple weeks. One day I was driving along and it started pouring black smoke out of it. 02 sensor had gone on it. Never kicked a code or anything.

[we4turbobuick]

I think i narrowed my problem to two things the translator or the maf sensor. I found this out by putting the stock maf on and the car idles good ,but when i install the translator and Lt1 maf it goes to barely running. Is there a way to tell which one is bad?

[Steve Wood]

If the maf readings are correct...and the one at idle was correct....the n it is not a Translator problem

Need another point to be sure, tho...but that meant it was set right

So it does not make any sense to me.  If the ecm is reading 04 for maf input, that should make it have all the input it needs to have the idle controlled. 

If the maf/translator is the problem in spite of the above, I have no idea how to separate the two without swapping one out.  Would be cheaper/easier to try another maf, I think.  Earl was selling some that he tested out...or go to a parts store and get one and then return it if it does not fix the problem? 
Borrow one from someone, or wrecking yard.

I am sure that more than one translator has failed...elect ronics are not 100% reliable, 100% of the time.

Does it keep running when you blip the throttle?

[we4turbobuick]

If i got to the parts store what year ,make, model do i get for a Lt1 3.0" ?

[Steve Wood]

Earl is the maf expert...but I think the 96 Impala SS used the 3" Lt1 version

[Steve Wood]

http://www.ihadav8.com/forum/index.php?topic=4059.0

[we4turbobuick]

I got a new stock version O2 sensor and its doing the same thing. Can this be a computer problem ? it just runs bad when I plug the translator. it even idle ok ... without anything plugged into the MAF connector on harness.....

[Steve Wood]

unplugged, the ecm goes into limp home mode, turns on the check engine light, and allows the engine to run--poorly when you open the throttle but it should idle.


When you connect the stock maf, do the O2s read 000?

[we4turbobuick]

it stays in the 700 -800+ range .... the only time it stays at 000 o2's is when the translator is plugged up ..... one other thing I noticed when I opened the translator it smells burnt.....

[we4turbobuick]

Thanks all a new maf fixed my idle problem! I still have my original problem  With car sputtering at will. Im gonna get a powerlogger then maybe you guys can help me narrow this issue down !! Thanks you guys again ill be back with real data soon!!!

[Steve Wood]

that was a strange one!  at least you made some progress

[we4turbobuick]

 can a ecm be bad or have issues without it throwing a code? I know that with the turbo tweak chip my o2's should be in the 700-800's. it keep falling below 100 or be stuck on 000. Are there any other parts or sensors can be bad that can cause this the only one that I can think of is the ecm ..... but im just guessing.

[Steve Wood]

It is possible but not very probable.

You can check the o2 sensor voltage with a meter and see if it is showing that under the hood.

If it is not, then I would look at my grounds on the back of the head to be sure all are snugged down with no wires loose in the crimp on connectors and no wires broken off.

Otherwise, it would seem to be a fuel pressure problem.  Did you ever turn the fuel pressure up to 50 or more to see if the symptoms changed?

[Steve Wood]

Also, when the sm reads 000, is the sm light blinking like the car is in open loop?

[Scoobum]

can a ecm be bad or have issues without it throwing a code? I know that with the turbo tweak chip my o2's should be in the 700-800's. it keep falling below 100 or be stuck on 000. Are there any other parts or sensors can be bad that can cause this the only one that I can think of is the ecm ..... but im just guessing.

Steve's gonna get pissed at me again...but have you got a spare ECM you could try?