Nothing there looks too far out of the ordinary. With a low throttle angle and some engine speed, manifold vacuum will be quite high.

 

Just got a call from the dealership. The fuel injection spider was installed correctly (Thankfully). The only problem was the throttle body gasket/seal was not seating right. They also said that I still had a misfire while the Blazer is being driven. The technician says you can't really tell it while driving it, and he also said that the cause could be the aftermarket air intake and k&n air filter I have installed on it. I'm thinking it could be the Bosch spark plug wires. I have AC Delco plugs and changed them both around two years ago. I recently upgraded the coil to an MSD. I'll probably switch the wires, distributor cap and rotor over to all MSD eventually.

Gonna go pick the Blazer up in a few. I'll let everyone know how it runs.

 

What should the LTFT B2 operate at normally? I see both STFT B1 & B2 operate at 2.34, but LTFT B2 I get -.78.

I'm assuming LTFT B2 is the o2 sensor that is near the cat. I recently replaced that particular 02 sensor as a preventative measure when I replaced the catalytic convertor. I installed a BOSCH, and now I'm thinking I should not have done that. I installed around the first of December and ever since, I've had a little misfire/hesitation.

I still have the old 02 sensor. I'm gonna slap it back on in the next few days and see how it does.

 

Well I slapped the old o2 sensor back on, still had a problem with the hesitation and bucking.

I was almost about to be driven crazy....

Then....

I inspected the spark plug wires. I noticed on some of the wires' connectors had a bright orange/reddish rust color on the terminals. I went by Autozone first to see if the wires were under warranty, and luckily they were. I did the job in 2009. Testing the OHM's on each of the wire confirmed that at least 3 were just completely dead.

I replaced the spark plug wires and fired the Blazer up and took it for a test drive. WHAM BAM THANK YOU MA'AM!!! So far so good. I went ahead and used the Bosch spark plug wires again this time since they were free with the warranty, but next time I'm gonna use Accel or MSD.

Until the next episode....

 

When my 92 Blazer had about 60,000 miles it started running a bit rough. I started checking things out, seems both ends of the spark plug wires had turned green, as well at the contacts on the underside of the distributor & the rotor cap. I changed out the whole lot, put that die electric stuff on all contacts. At 160,000 I've not had that problem again.

Hope you put it on yours, it sure helps, and someone may be able to give the right name for that stuff.