Black Smoke followed by sudden death?

[Soundguy]

Farm told you what makes them go bad. if you are looking at the pump itself.. gear pumps develop wear between the gears and or side plates.. doesn't take much wear to result in bypass and lowered pressure output / no flow.

Soundguy

 

[Iplayfarmer]

Age, too much use, not enough use, normal wear, dirt in fuel, poor lubricating qualities of modern diesel fuel, ect.

Pick any 1 or a combination of several of the above

Farm told you what makes them go bad. if you are looking at the pump itself.. gear pumps develop wear between the gears and or side plates.. doesn't take much wear to result in bypass and lowered pressure output / no flow.

Soundguy

So, what are the chances that this one I bought will be good? I'm just worried about the "age" parameter that FWJ mentioned. If all of these G172's wear out their fuel pump at about the same time, I'm up that special creek without a paddle.

I had a scenario like this a few years back with my "vintage" Yamaha XS650 Heritage Special. The Automatic Timing Unit went out and I went through 4 or 5 salvaged units that were similarly no good before I finally broke down and got an aftermarket Boyer Bransden digital unit.

 

[RobJ]

If you have a drop in bosch in-line style like this there are only a few parts. Rollers, seals and the high pressure plunger and barrel. Personally I would have seeked out a local pump repair shop first. Sometimes you never know what you get, and if there is no problem, you are only out $50 for a check up!

 

[RobJ]

I'll get around to swapping out the pumps later.

huh? First thing I'd do is put on the pump. New seat and lift arms are not any good if the tractor doesn't run!!

 

[Iplayfarmer]

If you have a drop in bosch in-line style like this there are only a few parts. Rollers, seals and the high pressure plunger and barrel. Personally I would have seeked out a local pump repair shop first. Sometimes you never know what you get, and if there is no problem, you are only out $50 for a check up!

The pump is a bosch. But, my diesel mechanic friend came over last night to see what adapters, etc. he'd need in order to do the compression test and pump pressure test. We ran the tractor through some of its paces and his diagnosis was that if the pump is bad, there's definately something else.

What led him to this was that when he sprayed ether into the air intake with it cranking there was no pop or sputter or anything. I'm going to check some other things with it now...Valve clearances, etc. I don't know where I'm at with it now. I may end up with a nice new injector pump that I don't need.

 

[john_bud]

Ouch! Sounds like a bad case of tractor induced cashottame.

jb

 

[DreaminGreen]

Nurse anestitize the patient, we're going in. I feel bad for you Farmer thats the kinda luck I usually have. GOOD LUCK!!!

 

[Iplayfarmer]

Alright here's the update...

I gave myself a two hour limit today to work on it. I wanted to make sure I quit because I was out of time rather than quit because I was frustrated that nothing was going right. I figure I'm in this for the long haul, so I'd better pace myself.

I actually started today by seeing what I can get for a spray pattern out of the nozzle. I pulled the #1 and held a paper in front of it while my wife cranked it over. I got absolutely nothing out of the nozzle. Same result on #2.

After some tinkering, I pulled the pressure spring out of the nozzle and tried the pattern. That was the only way that I could get any kind of fuel out of the nozzle.

I'm back to thinking it's the pump. Here's my theory... The pump is weak enough that it won't overcome the spring pressure. That goes nowhere to explain the black smoke or the fact that it wouldn't pop with ether, but that's the part I'm working on now.

I pulled the old pump, and that's where I ran out of time. I'm planning on taking both the old pump and the new one down to Tractor Service on Monday and have them tested.

I'm actually a little more optimistic now that I know there's definately something amiss between the pump and injectors.

 

[RobJ]

When you reinstall the pump, make sure the fuel rack lines up with the governor control arm. That arm moved the rack to adjust the flow of fuel. Seen DIYers miss that a time or 2.

 

[Iplayfarmer]

When you reinstall the pump, make sure the fuel rack lines up with the governor control arm. That arm moved the rack to adjust the flow of fuel. Seen DIYers miss that a time or 2.

Thanks for the hint. I saw the control arm in there when I pulled the pump and made a mental note to not miss that when re-installing.

As for my progress update, I called three different shops before I found someone that thought he might be able to test the pump pressures. Everyone's comment was, "We don't do that anymore." The first guy said that all injector pumps had to go to Salt Lake. I refused to accept that so I called the second guy and he recommended the third guy.

Turns out the third shop got its start in the little town that I live in. That warmed the guy up a bit when he found out that I was a "local" and he seemed a little more optimistic that he'd be able to get pressures for me.

I dropped the two pumps off after work just before they closed today, so I hope that I'll get word back tomorrow what pressure each puts out. I took the fuel lines that I bought off ebay to the guy too. He seemed pretty excited to see those. He said that those will make the pressure a lot easier to test.