I installed a Granatelli on my 96 Z today, it came off a 94 Impala SS (buddy of mine)....I think the Granatelli's are the same for both cars....anyways now it starts bogging down sometimes after 3000 rpm's if I punch it. Any ideas?

 

Make sure the harness is plugged in all th way. Other than that you car will have to learn the new MAF or so i've been told. Give it a few days and see if it goes away.

 

Likely you have the plugs not in all the way or backwards or something..When I put in my gms maf in my lt1 it worked fine right off the bat.It didn't have to learn.You can just disconnect the battery for a ten minutes or so and then see if its improved.If not you have vacuum leak or something not plugged in or plugged in wrong.

 

Are they the same for both the Camaro Z28 and Impala SS? My car is OBDII and his is OBDI. Does it make a difference? I looked it up and they have different part numbers, but the 82mm sizes are the same? So i dunno...Open to all suggestions

 

your car does not learn the maf sensor

it has to be reprogrammed. your af ratio is off bad because the pcm thinks the maf is still stock. its pulling in more grams of air per second than it thinks, then the o2s try and corect for it. but when you go into wot (or power enrichment mode) the pcm uses the mesuerment from the maf to set the af ratio and its off. and whats happening is your o2s are showing a lean condition (high blm, above 128) under normal driving and when you go into pe mode its taking the last block learn multiplier (LT BLM) adding extra fuel. it thinks your running under a lean condition and the pcm is seeing a LT BLM above 128 so it uses cell 15 and adds that fuel to your predetermined a/f ratio in PE mode.

put you stocker back on. and sell the Granatelli becuase you dont need one until you get over 500 rwhp.

 

I just took the car for a ride around town to see how it was doing. It seems very "skippy" sometimes throughout the throttle. If I go up the rpm's slow, you can feel it just drop soooo much power from 4-5k and then it pops back up again. But if I nail it like I were racing, it just screams right through the powerband with no loss of power that I can feel, and I can definitely feel an increase in power. DEFINITELY! So I dont know what to do. I think I noticed the fuel pressure dropped a little bit after the install (I have a gauge), I'll have to check that out tomorrow in teh daylight.

 

I have the Granatelli MAF for my car and it worked
perfect from the first moment I installed it. There
are lots of MAF stories out there but I have not had
any problems. Even the wide ban from my dyno runs
was fine (just a tad rich).

 

A b-body and F-body use different MAFs from the factory so the Granatelli calibrations are different for each car.

The Granatelli is junk anyway though it tries to trick the pcm into running th motor leaner than stock at WOT by feeding it what amounts to false info. A much better way to get it to run leaner than stock at WOT is to have the pcm reprogrammed and use a stock MAF. Timing and fuel adjustments are why a reprogram feels so good, the Granatelli is trying to trick the pcm into making the fuel adjustments, only half the equasion. Someone on the Impala board lost a motor to one of these things and numerous other just had drivability troubles like you are and worse.

 

If I were you I would just get rid of it. It's not worth the trouble for very minable gains (if any). It's not going to be a worthwhile modification for you.