95 12 valve rough idle on warm start

turbo246 · 11-30-2010, 07:51 PM

I did some research before Im posting this, but I wanted to get a few of the 12 valve expert opinions on here. My 12 valve is a 95, just turned 72K miles. I sold my car and have been driving it to work everyday for the past 2 weeks. I started noticing a little issue.
After the truck has been fully warmed and its shutdown and cools down to about 100-140*F and you restart the truck every once and a while it will start with a rough idle/slight miss. No smoke at all, just you can feel the vibration of it not running perfectly smooth. THEN if you shut it down and restart it runs perfect again. It did it to me earlier, it starterd right up with a rough idle, and I revved it a bit and you could still feel it in the revs. I shut it down, restarted and it was fine. Has happened about 3 times to me.
Its all stock, fuel filter was changed in spring (5,000 miles ago) running white bottle of power service. I have only noticed this since the weather started getting cooler, ran it all summer in the heat and never had it happen.

Besides that truck runs perfect, no white smoke no roughness anywhere else, its only after that warm start (it will not do it if the truck is still hot, its only when it has cooled to about 140)

I played with the shutdown solenoid and it seems to be working fine, i lubricated it and fiddled with it when it was idleing rough.

Any ideas?

illflem · 11-30-2010, 08:07 PM

Sounds like you have a leak sucking air.
Leaks can suck air without leaking fuel.

By far the most common leak is the 5/16" hose in red below.
Remove the fuel filter to gain better access.

turbo246 · 11-30-2010, 09:13 PM

Quote:

Originally Posted by illflem

Sounds like you have a leak sucking air.
Leaks can suck air without leaking fuel.

By far the most common leak is the 5/16" hose in red below.
Remove the fuel filter to gain better access.

thank you! i will check that when i grab a new filter tomorrow. for the hell of it tonite i put a wrench on all the injectors and i was able to turn on about a half turn or so, and the rest i couldnt budge. so maybe that was it.. who knows