[Old man]

New to EFI and superchargers.

I have 5.0 full length headers, TFS heads, TFS intake, Cobra/HO kit Vortec with MSD boost retard. New plugs, all else in good shape.
Has new Summit high volume pump in tank and booster pump that came with blower kit. 65 mm EGR and TB.

Ran 109 MPH 1/4 mile smooth with 19 lb injectors and stock MAF. Just what I expected.

Added blower, 30 lb injectors, and MAF calibrated for injectors.

RPM/Boost is:
2000 2 lbs
3000 3-4 lbs
4000 4-5 lbs
5000 5-6 lbs
6000 6 lbs
6500 6 lbs or so.

Now gets so rich at 3000-5000 it bucks bad every second or two. At about 5000 it starts to get smooth and pulls real hard up to 6500 or so.

No knocks, pings, rattles. Car smells like rich mixture after a run. Stock O2 sensors say rich. Do not have my wide-band O2 and recorder for data installed yet, but I have one.

I also have Tweecer so I can change computer.

Does the Vortec FMU need changed for the 30 lb injectors??

30 lb injectors too big??

Best way to handle rich problem??

Thanks, Tom

[uedlose]

yes the FMU should be changed with different injector. Is the 6psi all you gone to run? if so I would ditch the FMU and do the tune with the Tweecer or if you don't want to do that see if you can pull some fuel out at the rpms you are having issues. Be careful I would also hook up the wide-band before I made to many changes. did you close the gap up on the plugs? just making sure you are not getting spark blow out.

[Shine1Stang]

I would def hook up that wideband and do some short street runs. I was having problems with a popping/backfire on the top end. I thought it was running rich so i finally installed my wideband to c. At wot my af was 9.6!! Way too fricken rich!!!

[Old man]

Thanks.

I've installed my wideband oxygen sensor and recorder. Now I can get a digital recording of mixture, RPM, timing, fuel pressure, boost, and G force under various conditions. I didn't want to spend $1000 to dyno the car every time I change something major, so I bought all the stuff I need. I can change the computer myself.

It was way too rich because of the increased fuel pressure with the FMU, plus I'm running 30 lb injectors without a whole lot of boost. I bought a pack of disks that control the FMU. This way I can use the fuel pumps I have and the FMU already installed and fine tune by adjusting the computer. Plus I'm thinking I'll get better spray at low speeds with 30 lb injectors instead of shortening the time way up at low speeds on 45's by reducing pressure at low speeds
.
Finding the right fan belt was even a job, but it all fits well now!

I need to get a few idle to 6500 RPM pulls in a gear to see what to do with mixture.

What a job this is!

Tom