anyone know of a website that explains in detail how to lean out a car after a blower install. to be more specific, its a 97 LT1 with a MAFT+ and an auto X ray scanner. anyone? thanx

 

What are you using for added fuel on the blower.... FMU? super-fueler?.... no one can answer your question without knowing that info.

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Fred
94 Formula A3+1: 381/TH400+OD/N2O

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11.513@115.59 on motor; 11.162@127.67, 1.643 60' on a 125-shot. Going with a 275-shot this year

 

How much boost you doing (intercooled?), what injectors size, you got a pump on that?

Hal

 

As Fred and Hal's posts suggest, you aren't giving us near enough information to even begin to help you. Please post the details for your setup. I would also like to know how you have decided it is "running rich" and under what circumstances you observe this condition (I assume it's WOT, but is it?).

Keep in mind that running a bit rich costs only a few hp and provides some added safety in the form of decreasing the chance of detonation. A typical blower car should run an AF ratio in the region of 12.5:1. As rich as 12:1 is ok and this is the area that may give you a little black smoke under WOT. Unless you have access to a wide band O2 sensor if what you are seeing is a bit of black smoke at WOT you may be best leaving things as they are.

Rich Krause

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'95 Z-28 383: Vortech, nitrous, etc.
AIM: rstevenkrause

[This message has been edited by rskrause (edited August 30, 2002).]

 

ok sorry for the lack of info here, I have an FMU and a NOS inline pump for added fuel, my charger is an 8 lb. intercooled, i have stock injectors, and how i know its running rich??? well the most obvious clue is because i hooked up my auto x ray and scanned the computer and it said system too rich (bank 1 and 2) , another way i know is because my fuel tank goes empty ALOT faster than it did before,(and I am easy on my car so i know thats not why) , another reason is because i can tell it has fouled one or two of my plugs from how it sounds, also it smells like raw unburnt gas real bad, it blows black smoke when i goose it, and it cuts out pretty bad (mostly at high rpm) kinda like a misfire but it even did that long before it fouled the plugs. so, with all this info, can anyone help out?

 

Its probably not rich at WOT. I have a 97 and the 02s read around 870 with just 5#. Now idle and cruising my be a different story. What are your blm at idle, cruise, and wot? Also, do you have 02 readings for those conditions as well (not sure what an auto x-ray scans).

There are a host of things I would recommend but most of them would change if your WOT are scary (which I imagine they are with stock injectors and 8#).

If you changed to 30# injectors and an adjustable fuel fegulator then you have something to work with. I would then say to adjust down to 40psi at idle and set the fmu (if its an ati adjustable) to the appropriate 02 readings at WOT.

Hal

 

I STILL have pretty much the same problem as dasmoothtalka. I am running a powerdyne 4.5 psi, solid intake tube, 160 thermo, the powerdyne FMU, and stock everything else.

I have most of the same problems he has (runs rich and carbons up the plugs all the time, black smoke comes out at WOT, etc.) I have been trying to fix this nasty lil problem by using LT1-edit to calibrate the MAF (to make the AFR a constant flat line, as it wasn't before---low rmp's were way higher) and told the pcm that I have 28lb/hr injectors when I really only have stock 24's (in hopes that there would be less fuel being sprayed into the cyclinders. Now, the car doesn't idle rich anymore (plugs are clean and the BLM's run as high as 154).

BUT...

the car runs rich during normal driving appearantly, because the plugs are getting carboned up pretty badly. BLM's during normal driving are at 128 or real close to it. So, I am at a total loss here, if the BLM's are normal, what the hell is wrong with this thing??!!!!! Is running rich a common problem after adding a blower? Is there anyone out there who can help us???


Rich Krause I know you are the man at this, can you help us out???


Thanks a lot!

-Mark

 

Oh yeah, I forgot to add a few things.

1)The BLM's are fine at WOT, at 128 or real close if not.

2)The fuel pressure is fine, I have checked this a million times.

3)There are no post-MAF leaks, I have taken the blower off several times and event leak tested many of the connections!

Could my O2 sensors be bad? Do you think that they could be carboned up from running it rich before? They have 76k mi on them. The only thing is that the left and right both yield BLM's that are very close to eachother so, I dunno. The other O2 sensor readings, in mV's, are all over the board and I don't know if those numbers can tell much.

4)I have logging files if anyone would be willing to take a look at them or needs more info.

P.S. Rich, if you would be willing to help me out and are still in the Buffalo area, I could drop by some weekend.

-Mark

 

i agree......whoever rich krause is....please help. i dont even know where to start. Ive got a auto xray and a Mass Air Flow Translator+ but I just dont know which readings on the autoxray to pay attention to and how to correct them. lol