'88 5ktq sometimes no start, bad Idle

[Britt Crowell]

So my '88tq Has some idle and sometimes starting problems.
When it wont start it acts like it has a bad vacuum leak. i.e. starts for a sec then stalls.
So I cant find any vacuum leaks from any hoses.
Its been running for the last week or so.
Last two days have been cold here in Colorado and it wouldn't start today.
I've kinda had a suspicion that the injector seals are leaking.
And the last time it wouldn't start and today I put a garden hose in the plastic injector cooler shroud and bam it cranked right up.
So am I on the right track that the injector seals might be leaking that bad?
It only likes to Idle about 600-700rpm too. and occasionally pops, or a small backfire? (what's that about?)
The car has about 205K miles on it and a badly cracked exhaust manifold. 
Thinking about a striping it all off. And fixing it up good.
Even have a fresh rebuilt turbo to drop in it. maybe do all new injectors too.
What you guys think?

Britt