First - a little perspective.
"complicated with uninvolved parents"
I too work in a ...low income, English Learners.. Inner city Los Angeles - so about the most low income, highest population of English Learners you can get. So the tag of uninvolved parents is complicated in our situation. Its too simplistic to use that description as an overview of their thinking. Here are some things that go along with our particular area:
They work alot. Many of my parents have multiple jobs, working many more hours per day than a typical 9-5. they have night shifts often that keep them away from their family at times when other families might be looking over homework completion. It is exacerbated if there is a single parent household.
Language level- If the child is a Language learner, chances are the parents have a lower fluency rate and the home language is other than english. This at times leaves some parents to be unable to help with homework tasks.
respect - I find that the parents in my area have a huge respect for us, our profession and education in general. They know that education is the key to a better life for their kids. They trust us as the experts and have a hard time seeing how they can contribute.
work. - One of the cultural aspects of my area is that parents respect the value of working. Many a parent will use this as a bridge into the classroom. If you can express your ideas within the framework of the work you would like to see from the student, they might be more receptive.
So given the above - here are some things I (along with my colleagues) have done:
cultural fairs - invite families to bring a dish (of their favorite recipe) to meet and eat at the start of a year.
parents night - explain homework policy and have a system in place for parents to check homework even if they dont understand the language. start a homework notebook system so parents can check off work completed, teachers can note work missed.
translation - a person on staff who can communicate regularly with these parents is key - a staff aide, secretary, parent volunteer who can make phone calls often.
Use their strengths - have a play coming up? find out if any parents are good with carpentry for set design or sewing for costumes - they can come in and teach the designers.
open door policy - my parents dont all have nights off, so I ask them to come anytime. mostly I get before or after school. i have at times come in later at night, really early and a few times on a weekend. It is important to always have a translator.
email and notes.
larger school functions as a bridge - science fair, assemblies, math comeptitions, spelling bees - always invite.
planning groups - need an extra set of hands to complete that larger project? end of the year festivities? field trips? many a parent have time during the day.
Im sure my list has nothing new or unique - these are probably all things you have thought of. I think the key is access. If you make access to your school available and you let it be known you *want* help... they will come.
Good luck to you!