Bunch of engine work took me from 12.6 to 14.5mpg highway

So I'm so happy about the results of my latest upgrade/repair I thought I'd share my results. For starters I make the trip from Cleveland to Cincinnati about 12 times a year and use my suburban for about half of them, and I have a scangaugeII on the Burb, so I have a good account of fuel used, I also do to old fill-up math just to make double sure I'm not getting false numbers.

So here's what i did to my '97 K2500 7.4l Suburban between the last two trips.

Bosch injectors (same flow rate as OEM)
new FPR
New coil, cap and rotor
new intake gaskets
--these were done because I was having the long crank bleed down issue, on mine it was a leaky injector and a split vacuum line on the FPR--

Cleaned all of the built up grim 198k miles puts on the intake manifold and the throttle body by hand.
Ran sea foam thru the intake (this was the first time I've ever used seafoam)
Used motor medic - motor flush (again a first time)

so after putting it all back together Murphy's law caused the water pump to start leaking, costing me another $40, but it was a pretty painless swap.

now the 12.6 mpg i thought was inline with the way I drive (about 10 over and i don't tailgate), and this last trip wasn't any different, it was hot so the AC was on the whole time, traffic was typical including some stop and go in Columbus. Also this is strictly Highway mileage, when we get down their we use my inlaws accord for touring around town every time we take the Burb.

When I started this project I quickly felt like I was in over my head there's alot of things that are a PITA to get to or to just to get off the engine. I'm very happy with the results, I would've been happy with just the quick startups, but now the engine feels stronger and seems to be getting much better gas mileage.

Awesome results! I'm going to have my FPR and injectors done one of these days as well (long warm start issue is annoying).

Have you noticed any around town change in mileage yet? I do mainly city driving and average a tad under 9mpg by my hand calcs.

I wish I got 14mpg all of the time. Most of my driving is back roads. Injectors and proper fuel system maintenance did get me in the 13-14 range though for when we take the truck on road trips.

The only way I can drive my truck, which is admittedly only a 350, is to remain ignorant about the fuel mileage. I refuse to check it at all. Period!

Next up, you should try an electric radiator fan!

Awesome results for basically a glorified tune-up though!

Ironhead said:

The only way I can drive my truck, which is admittedly only a 350, is to remain ignorant about the fuel mileage. I refuse to check it at all. Period!

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Last tank i ran through my truck got 63 miles full to a quarter. But when my truck gets drove it only goes a mile down the road to work and a mile back or i gotta haul something and usually warms up for 10 - 15 minutes before it moves. I dont drive it very often so i like to let everything *** lubed up good before i go anywhere. On the interstate i can usually pull 200 out of 18? Gallons goin 80mph

It's hard to say around town, since it's horrible to begin with and in stop and go traffic just being light on the gas at a few red lights can make a big impact, I was getting around 9mpg according to the scangaugeII per trip to work and now it seems to be around 10mpg and sometimes I knockoff a 12mpg, I live a hilly 3.5mi's from work so it's all city and hitting 2 red lights compared to 2 green lights makes all the difference. This weekend I'm camping pulling a 3k# popup, I'm guessing it will have almost no effect on the highway mpg since my 6k# boat only drops it about 15%. doing the math this repair/upgrade costs about $200, and if gas costs $1.95 it will pay for itself in about 12k miles, or about 2 years, maybe less since it's not annoying to start it more than once a day I'll probably drive it more.