Still no fix on this issue! However, Fuel pressure is fine, ground is all good. Still coming up with MAF sensor code but feel that is a false reading because of an underlying issue. Replaced the EGR...no difference. Now the kicker...replaced the MAP (finally), took it out on my 2 mile test run (a country block). First lap still bucking me around until the last 1/4 mile so I did another lap and absolutely no bucking or hard shifting...ran great. 30 minutes later decided I would make a run into town to get dog food and put gas in the truck with some fuel inj cleaner. Back out of drive and take off less than 1/8 mile and the bucking begins. Go back home and pull the MAP off to check it and the little orange/red knobby thing snaps off and falls into the throttle body straight into a chamber...can I have anymore luck?

So question being was it a faulty MAP or is it something else? Have another MAP ordered for pick up at 3:00pm today. All I can do is try. If this doesn't work, it's going to the shop

 

i would check the wiring going to those to sensors you might have a short or a short to ground in the signal wire going back to the computer giving it false signal when you checking them wiggle the harness around you should be able to get a new connecter for those sensors from Autozone

Sean

97 4x4 burb

 

I'll check ll the connections again after i pick up the replacement MAP. Will keep you posted.

 

I give up...Truck is going to the shop today. MAP sensor made no changes and all connections have been checked and double checked by my son.

Before I take it in can anyone tell me am I missing something. This is what has been replaced

Distributor
Plugs and wires
Water Pump (doubt its related to current issue but needed it)
Thermostat (Same as above)
O2 Sensor
MAF sensor (Twice, thought maybe we got a bad one)
MAP sensor
Checked ground to fuel pump
EGR
Fuel Filter

If I unplug the MAF it will run rough but the lack of power, bumping and hard shift go away. As soon as I plug it back in all goes haywire. Is it possible I got a second bad MAF (I am thinking doubtful but....). maybe bad computer? I don't know anymore. I am beginning to hate the mechanics of Chevy trucks!