M816 power questions

[AMGeneral]

Thanks guys,I'll try one or both tomorrow,I may have stated something wrong,I only need the intake heater during colder weather(40 degrees or less overnight)and it will start without it,just a lot of white smoke.I never use either or any other spray starting aid.It will fire right up within 3 to 4 revolutions of the crank any other time of year without any heating.It doesn't have much(if any)blowbyand doesn't use any oil,so I don't believe it's worn out.

 

[WillWagner]

Ron, Upload the TM here, i'm sure others can use it. I'll take a look at it. AMGeneral, does it smoke white real bad at any temp on the 1st start? If so, probable cause is injectors, too much leakage between the barrel and plunger. Try the diesel douche 1st though.

 

[73m819]

i forgot about the tm library,ill try to day

 

[AMGeneral]

Will,It only smokes white when it's cold out,In warmer weather it starts right up with very little if any smoke (white or otherwise).

 

[WillWagner]

Try the flush and see what happens.

 

[AMGeneral]

OK,just went out and checked my inj pump,I have a PTG pump(small sheet metal circle behind the throttle shaft arm with a clip holding it in) my variable speed lever doesn't move at any point during regular throttle use.It took 20 to 25 seconds of cranking at 1/3 throttle a 46 degrees ambient air temp before it fired up.Is this normal/not normal,hopefully i'm going in the right direction here.

 

[TacticalTruck]

I have a PTG pump(small sheet metal circle behind the throttle shaft arm with a clip holding it in)

The PTG pump is not exernally adjustable and that is why I was asking if you had changed the spring and fuel button. It was my understanding that the spring controls the governed speed and the button sets the fuel rate. In the pdf drawing Ron posted they are located under the cover shaped like a traffic cone near the #9. To me, your wrecker sounds pretty typical, 38,000 pounds being drug around by a de-tuned GI 250.

 

[WillWagner]

No, it's not normal. An 855 will start with 0 throttle in most any weather. Heres my best gut feeling from 3000 miles away. You have almost no smoke wuth a PTG pump that is fresly rebuilt. still have low power and hard starting with new filters. The only thing else I can suggest without spending $$ is to fill a bucket with fuel, go directly from the bucket to the fuel pump inlet..yes, no filter, it will be OK for a few starts! Try to find a clear hose to use. Start it, throttle it a few times and then shut it off. let it sit overnight. Check to see if the fuel has bled out of the hose, back into the bucket. If so, the pump seals are junk. If not, meaning the clear line is still filled with diesel gas up to the pump in the AM, start it. If it still takes a long time to lite, I would do some injectors. Like I said, best guess without putting hands on. I have only seen an issue sort of like this 1 other time, on a Crown firetruck. Wouldn't start unless the block heater was plugged in, even at 60 degrees, overnite. Couldn't see the blow-by. The only real way to measure it is loaded, thru a .203 orificed fixture.

 

[73m819]

my 819 does 65 at 2000 down the freeway, HATES longggggggggg hills

 

[TacticalTruck]

my 819 does 65 at 2000

Hmmmmmmmmm, what size tires do you have? You should have 12.00X20s which I don't have here to get a diameter measurement. Fifth gear should be .78:1 and the rears should be 6.443:1 and I measure about 41" diameter on the 11.00s on my M816. At 2000rpm on the engine you are turning approximately 400rpm at the wheels. I figure my 11.00s have an 11' circumference which puts me at 50mph which jives with my experience. To get 65mph at 2000rpm, by my calculations, your tires would need to be 54.6" in diameter.
Jeff

 

[TacticalTruck]

The cranking time is excessive but I'd still argue the power is not unusual. One basic thing I found early on with my wrecker is it requires four HOT batteries for a quick start. It seemed like it was cranking at a reasonable rpm but would struggle to start at low/cool ambient temps but all things the same except four fresh batteries or a slave off another vehicle the truck would start instantly. Maybe this is symptomatic of another issue.
Jeff

 

[timntrucks]

i am just starting to have a problem with my 816 seams to be idling rough, i have not changed the fuel filter yet and i see there is a very little fuel that came out of the manual pump in the cab and i see alittle fuel around the fuel return line(i think it is) when i got my truck from GL it didnt have a pump on it . i traded some parts and got a nice looking pump off of a cargo 5 ton. with the same 855cc engine. does anyone here have a air clyinder kit for the wrecker, or maybe a bad pump with the kit. give me a shout im down in louisiana gi1ton4x4@hotmail.com

 

[73m819]

jeff , my tires are 46" tall, unless i have the wrong speed-o adaptor(one for the 1400 tires) my speed-o hits 60 then goes past as if there was another 5 mph mark, my wife followed me one day before i got the speed-o working and said i was doing 60 or a little more and that was not the freeway, thats all i can say not sure what this all means

 

[AMGeneral]

Thanks,I'll try the fuel line tomorrow.Everything I was seeing was pointing to injectors,but I was hoping that I was wrong.This truck had been sitting for quite a while before I bought it,but low miles/hours(5585/595).I don't have to give it throttle for it to crank,it will crank a 0 throttle,it still takes the same amount of time though.

 

[73m819]

i was wrong on the tire highth, its 44 not 46, must of had a stretchy tape

 

[AMGeneral]

Well,looks like i'll be pulling injectors in the next few weeks.Same problem this afternoon,after letting the 816 sit all night and checked the clear fuel line I installed,full of fuel clear up to the pump.It still took 20 seconds or so to fire off,so I guess it's injector time.Thanks to all for the advice.

 

[WillWagner]

One more little thing to check. There should be a little knurled knob on the fuel shut off valve, the one the wire is giong to. If the coil is swolen, it will cause low power and hard starting. With the engine not running, turn the knob in, 'till it stops, you might need to use pliers. Start it in the AM to see if it still hard starts. THE ENGINE WON'T SHUT OFF WITH THE KNOB TURNED IN! this is the FSOV bypass. just turn the knob out and the engine will shut down. (make sure the ignition is off though)

 

[AMGeneral]

Ok,got my rebuilt injectors today,$28.70 ea,cheaper than Deuce injectors.Also going to replace my fuel cut soleniod to be on the safe side,I'll post the results.

 

[timntrucks]

can you tell me more about the vs lever? lost here , havnt done much to my m816, but im having some kind of fuel problem, where is the best place to get oil and fuel filters?

 

[AMGeneral]

The VS or Variable Speed lever is an external governer for controlling engine rpm during crane and rear winch operation.It will be above and slightly rearward of the foot throttle,it will also have a small air cylinder going to it on the opposite side of the injection pump which connects with the clutch disengagement air cylinder on the side of the transmission.That is assuming you have the proper injection pump on your truck.