Ok sounds like that's the next order of biz. I will check at the filter tomorrow. I am doing my bathroom tonight and don't feel like laying under the truck in 28 degrees. That's for the advice, Captain. You've been a huge help.

 

Long as you have the fuel line disconnected, you can activate the pump and check volume, should squirt out a quart in 30 seconds.

 

Just a quick update. I seem to be getting slightly better mileage than before, at approximately 13 based off the gauge vs trip mileage. This morning was a very odd morning for the truck. It was about 24 degrees when I went out to start the truck to warm it up for the trip to work. I go through the same routine everyday, where I warm the truck 8-10 minutes before driving. She cranked and fired imediately, the seemed to stall out, but refired on her own. Never had that happen before. So I shut it down and restarted and everything was fine. The trip to work is 98% highway, and I set the cruise at 62 every single time, as this is where I seemed to get the best mileage out of the other blazers I have owned. I got up to speed and set the cruise (revs are about 17-1800 IIRC) and as soon as I took my foot off the gas to let the cruise take over, a got a sharp and very hard lurch, almost like it locked into 2 gears for a second. No MIL popped up and no loss of performance was noticed. Almost the entire rest of the trip was fine, until I cancelled the cruise coming to work about 18 miles later, where it did the exact same thing. Again, no MIL or loss of performance. I parked the truck for a little over 5 hours and drove home for lunch, where everything seemed to be fine. Same with the trip back and fine for the rest of the day. I will be checking fuel pump volume output ASAP. Is there anyone who has had hard lurches when letting off the gas in lockup? This is the first time this has happened with this truck. Last time I had something similar, I had a blown fuse for the MAF, but that threw the MIL as soon as it happened. This truck is acting very strange lately and I'm a little worried there might be more wrong than it's letting on.

 

Couple of things....

The 8-10 minute warm up is killing your fuel mileage big time! During warm up, injector pulse width is increased allowing a richer mixture, (same as a choke on a carbureted engine). During warm up you can expect maybe 6-8mpg, it progressively increases as the engine warms up of course. The colder the ambient temperature is, the richer the PCM makes the mixture, and the longer it stays rich. Factor in that the vehicle isn't moving during that time, 0 mpg! It takes some darn good mileage, for quite a while, to bring your overall average up to 13mpg. Not saying there's nothing wrong, but the warm up is affecting overall fuel mileage substantially.

The stutter you had... how long was the engine running before it did that?

 

8-10 minutes is bad? I didn't know that. Its just something I have always done whenever it gets cold out. Summer months, the warm up time is only about 3-4 minutes. I just really don't like driving.when the engine is even somewhat cold as wear is significantly increased. The stutter happened after about 3 or 4 minutes of driving, more than 10 minutes of running for the first, and the second after about 15 minutes of driving, more than 20 minutes on time.

 

And what would you recommend for a good warm up period? That 8-10 minute warm up time puts my right about, if not just past halfway between 100 and 210. Fully warm is about 1 notch below 210 on this truck.

 

Warm up is not bad for the engine, it's bad for the fuel mileage! The risk for engine wear occurs while cranking and in the first few seconds after start up, before the oil circulates. Whenever the engine is running and the vehicle is not moving, warm or cold, the fuel mileage drops. When it's below ~40F, mine has one piston that likes to slap, (had it for 200K miles). I idle it until the piston slap stops, ~10 seconds, and go!

The stutter may be happening when the PCM switches to closed loop. Stick a scan tool on it and watch the status, (open/closed loop). If that's when it stutters, it narrows the possibilities.

 

Ah good ol piston slap. Luckily this one does not slap......yet. I had a 97 that would slap for a goon minute or 2 at idle and until fully warm at RPM. That's where I got into the habit of warming up a decent amount before driving. I will run the rest of this tank down with my usual warm up habits, then the next one I will try with your circulate and go method. Not at all doubting what you're saying, I just want to see how much a difference that will make. Seeing as do not own a scan tool of my own (I use the MDI at my local dealer since I am good friends with the techs in the back) what scanner would you suggest picking up? I have no problem paying extra for one that will work that much better. Thanks again for the help, advice, and patience. You've gone above and beyond!

 

Captain, you were right! My converter is not fully locking up. Had the truck on the highway and the converter went into lockup, but I noticed the revs seemed a little high for 62. Took it to 70 and I was between 22 and 2300. I eased a little more throttle and the revs dropped just a touch. Let off and then got back on and it seemed to be a little slow locking back up. Almost like it "slipped" into lockup. So now my question is, do you think my TCC is bad or is my TCC solenoid bad? Still no MIL or driveability issues, other than the RPMs are 2 to 300 higher than should be.

 

Snapon Solus, commonly called "The Brick" in the industry, (cuz it looks like a red brick) is a decent, user friendly, scan tool. It will access engine, transmission, transfer case, air bag, ABS and the body control module. You can access camshaft retard, crankshaft position sensor relearn, ABS automated bleed, and almost full function/control of the BCM, view live streaming data, record movies, yada yada yada. You can't flash with it, but there are several things you can command with it. It's not top of the line and doesn't have all of the bells and whistles, but for a DIYer, it's more than you'll ever need. New software is expensive though, $1K every year, available through Snapon only. If you do it every other year, it's not so bad. You can usually pick them up (used) on Ebay for under $2K, just depends what software it has and what accessories come with it. It will communicate with USA and Asian, not European without special software and accessories. Software version 10.2 is good up to 2009.

On your trans, without checking line pressure, and short of tearing it down for inspection, I think I'd try replacing the TCC solenoid, sounds like the valve might be sticking. I'm surprised the SES light hasn't come on yet. Without locking up, it's not doing your fuel mileage any favors, that's for sure

EDIT: It shouldn't slide into or out of lockup, should feel like another shift point. Should be very noticeable on the tach the instant it locks up, RPMS will drop immediately. If you had a Solus, you'd be able to watch it