high idle after new fuel rail

[Glliw]

Hey guys, I just had to cfhange out my fuel rail and after doing so, my idle is between 1800 and 3000 rpms. It is not jumpy, just after every time I pull it out of gear it tends to be at a different rpm, but never below 1800 rpms. I have the idle set screw set in as far as possible. What could be the problem?

 

[WFO-TSi]

Whenever my car starts acting up I start my search for the problem in the place I was last working. In your case you mentioned the fuel rail.

Do a boost leak test and I am willing to bet that you will find a significant leak at the seal between the injector and the head.

Good luck.

 

[Glliw]

I can't imagine so. IT builds and holds boost fine.

 

[CanadianTSi]

I can't imagine so. IT builds and holds boost fine.

Just because your car builds boost doesn't mean you don't have a boost leak, it just means the turbo is working overtime to maintain your boost level.

You probably have a big boost/vacuum leak at one or more of the lower injector seals.

 

[kenamond]

Did you replace your injector insulators when you changed the rail? Did you replace with an aftermarket or OEM rail? I agree with WFO-TSi about the insulators leaking. They turn to from a rubbery, compliant material into a hard, plastic-like material over time. I just changed mine, and it was amazing how much harder the old ones were than the new ones (plastic vs rubber). I suspect that you broke whatever seal they had when you changed the rail, and they didn't seal up as well when you put things back together.

EDIT: Also, did you make sure you got the three rail spacers back in there before you put the 3 bolts back in? I'm sure missing one or more of those would screw up the insulator seals.

 

[nightracer91]

Can you here alot of air being pulled into the engine? If so, you have an intake leak, possibly on the injector o-rings. That is pretty common.

 

[kenamond]

Can you here alot of air being pulled into the engine? If so, you have an intake leak, possibly on the injector o-rings. That is pretty common.

Just so we don't confuse this guy, you mean insulators, not o-rings. The o-rings seal the fuel system where the injector plugs into the fuel rail, so bad o-rings would lead to a fuel leak, not an air leak.

 

[1GawdJunkie]

Definately do a boost leak test and make sure the rail and injector seals are good.

Also, if your car has cruise control you probably messed with the throttle cables, make sure to check the tension of the throttle line. Maybe loosen the bracket a 1/2 inch on the intake manifold and see if there is any inprovement.