Casey, my WBC does the exact same thing. I don't hear anything breaking up, no pinging, nothing, and it's only started doing it in the colder weather. The problem is that I get out of it as soon as I see the A/F go up.

I would suggest getting on a dyno and comparing if you could.

If I roll into it slow it's fine. If l roll in hard its still okay, for the most part, but it I stomp it the A/F shoots up. I'm starting to wonder if the WBC is just not keeping up, but in warm weather it read perfectly fine for me, I don't know.

 

If it's the wideband I am going to be pissed, but very happy at the same time

The weather is not going my way right now; tommorow is suppose to be a nice day. Maybe I can get things sorted out.

 

This board is just amazing, total strangers trying to help each other out. (even though they are in different parts, north, south east or west, it just doesn't matter) This is only one of the reasons I LOVE this board soooo much, and is always my first stop when I have time to read these theards. THIS BOARD ROCKS!!

Even though I'm stock (well a drop in K&N filter) with the best stock run of 13:46 @101.89, you just have to love this place. Two to all of you out there helping others out with there problems!!

Harold AKA MM

PS: Steve and other monitors, you have some of the best out there helping this board stay #1 in my book!!

 

Well; I tried another Widband Commander "brain box" and sensor. So, unless it's in the wire going from the sensor to the brain box that is not it.

I tried putting the 50# injectors and tune for them that work fine in the truck. That made no difference.



Now I do not have a clue what to do. Only other thing I have to try is the SCT MAF; gotta either try someone elses, put the stock one in, and a program to run it with 60# injectors, or put stock injectors and maf in it.

What if my Catalitic Converters were stopped up? My sensor is just after a cat. It has never gave me any trouble with readings being there.

 

OK, if anybody here can give me a suggestion that will lead to fixing my problem I will mail or paypal you $100 reward.

I am about at my end with chasing this problem; I am very close to returning this truck to stock and selling it. Someone please help; there is nobody locally I can take it to.

 

Casey,
What MAS are you running? On my truck with the Mag the stock 01 MAS hit 5 volts at only 4200 rpms running a 6# lower. I installed a SCT2400 that took care of that problem.

Charles

 

Not that the wideband sensor being behind the cat will cause your truck to run this way, but it isnt recommended to put it behind the cats.

Your readings might be off.

 

I have the SCT MAF already. I am just concerned that it could have a problem. I have tried cleaning it, but I did get one of the very first ones that came out. I don't know if there were any problems with them or not.

What has be puzzled is things were doing fine; then just slowly went to hell with nothing changing.

 

I think Casey you need to bite the bullet and get your truck on a dyno with a tuner that has data logging equipment. I don't know of tuners with that equipment in your area but I have seen guys post that have made the long trip from Florida up north that came back happy they made the long trip. I am sure Sal for one could fix you up. Then again perhaps someone on this board knows of a good L tuner in your area but I don't think there is otherwise guys would not have made that trip.

Charles

 

Check your voltage on at the pumps. Walbro's are notoriously in consistant in quality. If your voltage is below 14 volts at the pumps they will not pump the advertised amount. May have to add a KB boost-a-pump to get you there with the walbro. On the flip side the Toyota Supra pumps are awesome. Pump more and not so voltage sensitive. They do cost more but they are worth it. I will try and find a link with more info.

 

It's not his pumps Bill, he's verfied no fuel pressure drop when the truck is going lean.

How's the STI?

 

O.K. I have never tuned with the wide band O2 BUT on my supercharged Miata I had the same problem so I increased the fuel pressure.Test drove it same thing it would go bad lean at WOT the car ran fine and no detonation.So I added more fuel same thing one more time more fuel then it would fall on its face then go still showing lean.What the problem was the car was so rich it was soaking the O2 sensor and giving me a lean reading when I was rich I back the fuel pressure down to 42 static took it out and Bang full rich and it ran like stink.Maybe you need to go the other way very carefully and see if it changes anyting the wide band is more accurate but it may do the same thing if it is soaked in fuel.Also if I read your post right you said you had the wide band probe after the cat it should be before the cat to get a accurate reading right.I mean the cat will burn some of the raw fuel off making you reading show leaner than it is which is the oposite of your problem.Hope this helps sounds like you've done everything else.
jeff

 

That is a yes and no. I know it is staying above 50#'s, but I have not just held my foot in it when it is saying 13~14 A/F On my stock pumps when it was running right I know for a fact it would go up to 60#'s@18#'s of boost.

I have to ask how are you going to have 14v at the pumps. Yes, the alternator should put out somewhere in that range, but there are a lot of electrical losses getting to the pumps.


My motor is on borrowed time as is, but I don't want to blow it up with a problem like this. I would also like to fix the problem before a new motor goes in.

 

What is STI?

 

My Commander is doing the exact same thing and fattening up AFR made it worse, so idea of wet sensor may be it.