Fuel questions on 190xt

[John Achmann]

Got a 190xt that I had the pump and nozzles rebuilt. When I timed it I lined up the marks in the window on the pump. When I went to put the pump back on thought I’d check the marks on the crank pulley. It was at 23 degrees instead of the 26 as the book states. I did turn it to 26 and installed the pump. Tractor does start and run but it wants to wet stack some. I know that this is an unburnt fuel issue. Took it out and disked some of the field. It dried up but in about 5 minutes of idle it starts to get wet again. Just trying to figure out if it’s timing (I kinda don’t think so) or if this old girl is just tired. It was wet stacking and smoked horribly before. I did recheck timing after running and it’s on mark. I plan to pull valve cover and check valve lash in case I got one that’s too tight. Just trying to brain storm a little.

 

[DrAllis]

What pressure were the injectors set at ??? I would prefer 2800 psi and not more than 3,000 psi. How does it start COLD ?? It will start better COLD timed at 23 than it will at 26 degrees BTDC. If it starts relatively good COLD and runs well when working it and doesn't use excessive engine oil, not sure I'd lose any sleep over it. If it was doing this before you went thru the pump and injectors, looks like nothing has changed. If it has been running for years and maybe decades at 23 degrees BTDC, I don't think advancing it to 26 is a good idea. Why?? because the crank pulley is rubber mounted and possibly could have slipped. So, if it really was timed at 26, you now have it at 29 degrees and it should start pretty damn hard on a COLD start up.

 

[Dieseltech]

Timing will depend on whether the pump you have is the stock/fixed phase pump or the later pump with built in speed advance like later tractors use. AF suffix is no advance, AJ suffix has speed advance. Around my area I see some early tractors that have had later pumps installed a lot lately.
Some JN suffix have speed advance too. Wet stack trouble can also be lower than normal compression issues too. Later timing helps with cold starting, but engine might have a high speed no load miss if pump has no advance. That's why later pumps have the advance feature, for better cold starting, and less high speed no load miss trouble.

 

[Nordic]

I used to have a Perkins 248 that was wet stacking, even though it had low hours on an overhaul. I became suspicious of the brand (Shell) of crankcase oil I was using. After doing an oil change to a different brand I had no more problem.

 

[Snattlerake]

Old thread, what was the outcome?

Signed
Curious.