LOw compression

[AllenEM]

I think this maybe my starting problem? does it sound like it could be? once the the truck start with help it run good not much power. But will get up to 70 mph.

I put new GP
new GP relay
I have power at all 8 GP's but it will not start with out help. Good changed battery's, you can smell fuel went it cranking and we have fuel to all injectors.

So we are leaning to compression.
It's a 85 M1009 6.2

Anyone think of something else? I'm taking to a shop to check compression soon.

 

[mangus580]

Injection pump

 

[AllenEM]

Injection pump

when i got the truck for state surplus they said they changed it.

 

[doghead]

Did it ever run right, after they changed it?

 

[HardCorps79]

Consider replacing the fuel filter and the vacuum lines. Cheapest easiest thing, and probably needs to be done, anyway, even if there's another issue involved.

My truck ran decent when I picked it up, but was a bit rough and inconsistent. Changed the fuel filter and added some diesel kleen to the tank: it was like someone had put a new engine in it. Start-up which had been okay was suddenly smooth, acceleration improved and shudder at high-speed disappeared.

Also, the rubber in the vac lines deteriorates over time (these vics are 20+ yrs/old) and even pinhole leaks can allow enough air in to cause problems.

Fuel filter- $25 (NAPA #FL3136)
Vac lines- dirt cheap (3/16" if I remember correctly)

Oh, and change the air filter- a clogged filter can kill engine performance. ($7 for the FRAM, $40+ for a K&N)

 

[hobie237]

Since the vacuum lines don't have anything to do with the engine intake system, unlike a gasoline motor, they would only affect the transmission, not the engine.

There are a number of things that could cause hard starting, of course low compression is one of them. Just pick up a cheap tester and give it a shot.

 

[AllenEM]

Did it ever run right, after they changed it?

NO it ever started with out help but the truck runs as smooth as glass at idle and will run down the run 80 mph. but hills kill it and very low on power. also smokes (black) all the time.

 

[LanceRobson]

NO it ever started with out help but the truck runs as smooth as glass at idle and will run down the run 80 mph. but hills kill it and very low on power. also smokes (black) all the time.

80 MPH in an M1009 with stock gears is asking for a blown up engine or fried tranny. It was designed and built during the days of the 55MPH national speed limit. It's got nothing left to give at those speeds and.

That said, I agree whole-heartedly with the advice to change the filters and vacuum lines.

If you have not done so, use the "RESOURSE" tab to go to the TM section and download TM 9-2320-289-20 and follow the mechanical troubleshooting guide.

I'm pretty sure it starts with the filters.

Good luck


BTW, where is there a hill in OK? Little swells in the ground, maybe, but, hills?

Lance

 

[mangus580]

80 MPH in an M1009 with stock gears is asking for a blown up engine or fried tranny. It was designed and built during the days of the 55MPH national speed limit. It's got nothing left to give at those speeds and.

Lance a 1009 will do 80 with no issue at all... due to the 3.08 gears. I think you are thinking of the 1008 series with 4.56 gears


As to the problem at hand.... If you are getting lots of black smoke, it could be an air filter. Another thing to check is the timing. On the top of the injection pump where it bolts to the engine, there should be a line, with a corresponding line on the engine casting. they should either line up, or the pump line should be about a line width to the drivers side.

 

[hobie237]

... I think you are thinking of the 1008 series with 4.56 gears...

... in which case, 80mph is a physical impossibility with the stock tires.

 

[mangus580]

FYI...

80 mph in a 1009 is the same RPM as 55 mph in a 1008

 

[AllenEM]

... in which case, 80mph is a physical impossibility with the stock tires.

it will but I did not drive it there long but I drove from OKC to south central OK about 85 mile @ 65 to 70 most of the way.

we have retimed it two or three times. trying to get it to run right.

 

[hobie237]

No, an M1008 with stock gears and tires will not do 80. Period. Not possible. Redline in third gear with the 4.56s and 235/85/16s comes at 71 or 72mph. Any faster than that means that the engine is turning above redline, which would mean that at the very least, the governor is fubar'd, and if you ran at 80-85 for any length of time, chances are you fubar'd plenty other stuff along the way. If you really did run that fast, I wouldn't be surprised if you never get it right without replacing a LOT of parts.

 

[AllenEM]

No, an M1008 with stock gears and tires will not do 80. Period. Not possible. Redline in third gear with the 4.56s and 235/85/16s comes at 71 or 72mph. Any faster than that means that the engine is turning above redline, which would mean that at the very least, the governor is fubar'd, and if you ran at 80-85 for any length of time, chances are you fubar'd plenty other stuff along the way. If you really did run that fast, I wouldn't be surprised if you never get it right without replacing a LOT of parts.

maybe if I had a M1008 but I have a M1009 and it will run 80 mph