63mpg in a 1986 Isuzu Trooper Turbo Diesel

[Irie Jedi]

Ok first I want to introduce myself, I'm Jerry Olson and I live in Vail Colorado..... I was surfing the net tonight looking for information on a new or used turbo (mine is shot) when I saw a picture of my Tooper on this site. I think the truck is a lot of fun but I have been seriously rebuilding it this spring. Front end was totally rebuilt last week and the veg kit I bought is going in next.

Now I know I paid less than $3500 but I wont get into that, main thing is it has never gotten anything close to 55 mpg gallon let alone 63mgp. I averaged about 28mpg driving the 100 miles between Vail and Denver going the speed limits, and yes it smoked like a pig on the big uphill climbs. The high flow air filter helps a bunch and when I cleaned that filter last fall it had a lot more power=less smoke, still smokes like a pig uphill though. Fact of the matter is this truck which had just less than 180,000 miles on it when I bought (90,000 miles since the factory recall and rebuild) it has damage to the manifolds and turbos from excessive heat. Currently having a hell of a time finding a replacement for the turbo. The warped manifolds were easily machined.

There has never been guages for this in the cab or anywhere else or a turbo boost adjustment valve which is controlable from the cab that I have seen. I am kind of curious about what you are refering to on these mods because I know you mentioned them before I bought the truck from you, I really don't see these parts on the truck nor their reminats. I suppose if you drive the thing around at 10 to 50 mph you'll get better gas milage but not those figures. Smart cars barely get that and that's brand new technology not stuff from 1986!

My plans are to install an intercooler soon to prevent further turbo over heating, god knows when or it happened in the last 90,000 miles but my truck runability hadn't changed. I took the turbo and manifolds off originally to fix the exhaust leak on the exhaust side. The extent of the problem was not realized until that point.

After I get the veggie oil burning potentially adding a propane injection set up to make up for power losses on the veggie end. That is much later though. Once again I like the truck though is needing a lot of love, also I think the bigger tires do more harm than good unless I'm mainly driving slow off road. I think the next set of tires will be the BF T/A's in a 29 inch instead of those 31's you see in the last picture. They kind of bounce around too much, skinnier is better in the Rockies. If anyone knows of someone selling a TB209 Garrett turbo hit me up, the best I've found is a similar but not exact one aftermarket for $465.

Jerry
PS. I have pictures of this turbo's waste gate which is cracked deeply on both sides but the photos are to large to upload and I can not resize them right now.

[tasdrouille]

Hi Jerry,

I feel for you. With what was done to it no wonder the turbo is fried. First thing first, please revert the fuel pump modification that was done so fueling is back to stock. Have a look at all the boost/vacuum lines in the engine bay to find any bleed that was installed by the previous owner and make sure to get rid of that too.

You know, $465 for a turbo is quite cheap. Unless it's a cheapish Chinese-made knockoff, buy it. You should get on a Trooper forums and ask if anyone has a spare lying around.

[sandcruiser]

under 500 for a turbo is a good deal, usually.

I don't know the numbers on it- but search for LeBaron turbo. There was a gasser that was turbo'ed and often found in junkyards now. Might be a good swap for you. (might not!)

[bgd73]

I have 5 alloys for a trooper, 1987. I believe the 60mpg fuel, they needed turbo and tune. All OEM even today do not let full fire happen for fear of the engine...there is 5 year plans they need to keep. A diesel is a big thumper and owners have to make it. I grew up with much much larger diesels...and a 290 cummins chugging along at is best could suck down what a 550 cat does today...same mileages..hauling up to 20 ton more. Diesel has a secret, it is oems weakness. I too get "unbelievable" mileage with a 1781cc boxer and a jacked up sube with 10 gears (60mpg ironically). OEM does not like thier engines running..seems a certain oxymoron. Go for those forged parts, and tell em all..it is even more stunting when it is oem that hangs on for decades after the goofballs put it together. Like the project, glad someone contended with it..that whole generation has a good chance at something. gas or diesel. the most interesting cars I never got to (my locale is absolute car holocaust) is a diesel from the 80s. Another similar story of a nissan iesel pickup slapping a turbo on...same thing, doubles mileage and power is something to be giddy over. OEM has done alot of weird things...the 80s wasn't even half of the madness of what they do today...and the stampede spends its time laughing at the 80s. I don't even want to know wht they think ecomodding is...Good luck with the trooper. I can guess a melt down someplace, bottom or top end.

[jasonck08]

I'm going to have to call BS on the 63MPG. I doubt you even got over 40MPG in this car.

Proof, or perhaps comments from other people who know more about the isuzu trooper?

[MadisonMPG]

I love how tasdrouille just called it lol.

[Kiwi_ME]

I have a Suzuki Grand Vitara 4X4 with a modern 2.0 liter intercooled common-rail Peugeot turbodiesel and get a carefully-measured 33.6 MPG (US) on a normal road trip, typically driving at 60 mph on hilly country roads with a few small towns thrown in.

Like the Trooper, it's an un-aerodynamic box on wheels, and screwing with maximum power limits is hardly going to change the fundamentals of diesel efficiency when cruising.

[oldbeaver]

I cannot believe that economy.

This truck weights about 2 tons.
What is the engine you have?

Stock diesel Chevrolet troopers yield about 25 mpg in town and around 33 mpg highway. Gasoline ones yield a lot less.

Too good to be true.

Check your calculus. Make a full tank calculus. Check that you are using miles and not km for your results.

[kgwedi]

I owned a 1995 Isuzu double cab (KB280D) with a long range tank. (45 USG)
It had a big Bull Bar on front. I drove it for 140,000 miles, and averaged 29.6 mpg.
A very good vehicle.