A few weeks ago, I was R&R a few fuel lines and decided to see how stuck the GPs were. This in a '96 E300 606.912.

#3 came out like a charm. It was the only one. I tweaked on #4 for a bit but decided, hey, the GP system is working flawlessly, why mess with it.

Indeed, So I start the car, and its a little rough, but I assume its the air still in the lines. Nope, not when the GP light starts to come on at 65 mph!

So anyway, pulled the intake back off and removed the "stuck" #4, which I assume I shorted out when I was "tweaking it". Reamed it, and its neighbor #5 and stuck two new Bosch GPs in.

It still doesnt have the same flawless start it used to have. WTF did I do to it? It fires fine, but then one cyl srarts to nail a wee bit. By 40C the engine is its usual good sealing, strong running diesel.

There is still a small fuel leak behind the fuel solenoid ( stripped the T-30 bolt on one side), but this tiny leak never caused it before.

should I have tested these before installing? I dont like the nailing; this is my third and best running 606 so far. I dont want to mess it up!

I'll be going back in to EZ out that t-30 and put a Viton O on the solenoid, but what? VOM test the 3 new plugs or pull 'em and glow em?