I would have to agree.

 

Quick update guys:
replaced the TCC solenoid. Noticed a slightly faster lockup shift, more noticeable when cold. Started with the <1 minute warmup and I am up to 14.4 average MPG from 13.6 on my last tank. I replaced the solenoid about 2/3 through my last tank, so I can't yet tell if it has done anything for mileage. Revs are still around 2100 in lockup and it still "slips" into lockup once already at freeway speeds and unlocked with the brakes. Talked to one of my tech buddies, and he mentioned something about a bore in the valve body becoming worn down and allowing fluid bleed-by. There is a service procedure I would need to go through to ream said bore and use an oversized TCC valve. Not recomended as a driveway fix, so this will have to wait. Had the tech also do some parameter readings, and the truck is going into closed loop and running normal, but there is a slow R/T on the bank 1 O2 sensor. Not enough to trigger a light just yet, but is noticeably slower than the bank 2 sensor. Both sensors on the chopping block next week. Took the truck off the beaten paths today, since we have had almost a weeks worth of rain. She loves the mud but, damn, I really need that G80 rear end. Will update probably early next week with another tank down and hopefully new upstreams.

 

The kit for reaming the valve body has been out for a while and seems to take care of the problem, so I've heard, (I don't have any first hand experience with it). Seems like I remember reading that the slip is more common after the fluid warms up, which makes sense.

That's good news on the mileage! Oxygen sensors switch from lean to rich and rich to lean constantly. During its life, response time, (AKA reaction time and switching time) naturally slows down. Around the 100K mile mark, they have slowed enough to affect fuel mileage noticeably and might not turn on the SES light. That's why it's recommended to replace them. It's pretty common for them to react slow in one direction and not the other. Slow response time, in one or both directions, will decrease fuel mileage. The quicker it can respond to changes in fuel mixture, the quicker the PCM can adjust injector pulse width to keep the mixture closer to the target. Typically Denso, Delphi, and AC Delco tend to have a quicker response time than other brands. No need to do anything with the downstream sensor: Its sole purpose is to monitor the efficiency of the catalytic converter. It has no affect on engine performance.

 

Well, another offroading adventure turned out not so good this time I hit a decent sized waterhole, where a nice little rock was hiding. Needless to say, I hit the rock with my left front and got a little air. Thought nothing of this mishap, as it was quite fun for me (passenger, not so much. First time on the trails) I continued for a 10 minutes or so of just splashing around, but avoiding the hidden boulder. Now my alignment is cocked about 10-15 degrees to the left, and the truck pulls ever so slightly to the right. So, until that is fixed, I will not be updating my mileage readings, unless they magically continue this upward swing. HA! I will get the truck to the shop next weekend and get her straightened out, but this next week is way too busy to with hauling to give up the truck for a day or 2. I will update with fresh O2's and fresh alignment. Thanks for all the help and responses guys!

 

So while I had some down time, I decided to take off the upper intake to see how things looked, as I hadn't done this yet. The extent of checking the intake was with an LED and dentist's mirror. I noticed some washing on the #4 and #6 intake runners, a small amount on the #5 runner, as well as a small spot on the underside of the TB. I checked with the BAR gauge again, and the numbers are spot on with my previous readings. Still not showing a leaky injector or regulator. So my next question is, are the poppets on the #4 and 6 injectors getting stuck? Someone has been in the top end of the motor before, as the safety clip on the main injector connector was not in place and pinned underneath a vacuum line that was run in between some wires in the main harness.

 

Looks like you may have a leak in the rear corners of the plenum gasket. Doesn't appear it was sealing completely causing a vacuum leak. Odd # cyls are on the driver side A leakdown test would verify a leaky poppet. If leakdown is within specs, no leaky poppets Might want to consider the upgraded injector assy. Amazon & Ebay have some good prices. Delphi #FJ10565.

 

wow thats pretty nasty, although mine wasent very clean either after only 73000 miles.

 

Well, I figured since I'm in this far, I called into work for the day and am going to do a total top end rebuild from the pistons up. Taking the intake off is something I only want to do one time throughout the life of the truck, so I'm going ***** deep on this one. New valves, new gasket set, new head bolts, new intake (I have one laying around with less than 5K on it) and a new set of injectors, if my wallet can accommodate it

 

So got the motor down to the block. Things seem a little more dirty than I am used to, but I can't expect every Blazer owner to go as in depth as some of us One thing I really noticed, more than anything, was how fouled the plugs are, seeing as there is less than 250 miles on them! Well this is one of the reasons I am going so crazy with this truck right now. It's pure frustration at this point, and I am the type of person to just say "F*&% it, I'm replacing EVERYTHING." So that's where we are at now. I can't take another day off for this truck, but I will work little by little for the next 2-3 days and update along the way. Yippy!

 

P.S.
Captain, I know the drivers side cylinders are odd, but the runners run to the opposite side of the engine, making those the even numbered runners. Good call though. I thought I messed up for a second. I will definitely let you know how all this goes, and will definitely but upgrading to the MPI injectors before the motor goes back together.