motor idles at 2000. question about blocking of vac lines.

[pj91gsx]

I blocked off the egr vacuum lines but I didnt use a block off plate. I also blocked off lines to the thermostat and two to the Throttle body.

 

[mitsu_matt]

Was there a question here?

 

[pj91gsx]

. yes. sorry about that. Is it necessary to have the block off plate? or is it ok to have the vacuum lines blocked off alone? The car idled at 1200 at first with the egr valve, theremostat, and 2 throttle body lines blocked off. But it rises to 2000 after awhile. I let it sit for a few minutes and I couldnt get the idle down.

 

[pj91gsx]

This is right after a rebuild and letting the motor sit for awhile. only about 20 miles on the rebuilt motor so far. oil pressure and everything is great. just idling at 2000 is this normal when the motor is warm for it to idle at 2000? It idled at 1200 at start then warmed up to 2000.

 

[pj91gsx]

Ok I used a block off plate for the egr valve. Same problem. the biss screw is screwed all the way in. Do I need to eliminate another vacuum line? I just eliminated the egr valve lines and the thermostat vacuum lines. Could a bad O2 Sensor cause this?

 

[Jae]

You might check the choke sensor on the TB. I had this same problem on a Camaro recently and the electronic choke was not working properly causing it to idle faster as it warmed up to about 2,000 rpm and run rich.

 

[pj91gsx]

oh thanks. What sensor was that? Throttle position? was it a temp sensor on the throttle body? and there is one more its the one next to the throttle cable. I unplugged it when it was running and nothing happened I think it is probably bad.

 

[viprez586]

DSMs don't have a choke circuit . They're fuel injected.

Boost leak test your entire system. Eliminate unnecessary vacuum lines aswell.
While your at it, test your ISC motor (Idle Speed Control). You should be able to find a lot of this information at VFAQ or that search button aswell.
But yeah just make sure everything is secure and ready to handle pressure.

 

[pj91gsx]

ok. Sounds good. Im wanting to know, is there another vacuum line that i need to eliminate? the throttle body only needs the P. right? Could that cause it, because I eliminated the egr vavle and the thermostat lines. I didnt block off the actual thermostat ones because one plastic piece is broken off. do I need to block that off? I just took the vacuum lines off and blocked the other end. I hope that is fine is it? Also the motor has just been rebuild maybe it needs time? idk.

 

[pj91gsx]

oh yeah. boost leak test will be my next thing to do. It may be until Saturday until I can actual do the work, but I plan to have it figured out by Saturday.

 

[tqmx1]

Why dont you hook up the two water lines to the FAIV and see if your problem goes away.
With out hot watter running through it the valve stays open reseing the idle as the rest of the enging warms up.

 

[pj91gsx]

ok, I just read on vfaq about the ISC and the throttle position sensor. During the rebuild I took the throttle body and intake manifold and threw it in a hot tank. I did take the throttle position sensor off, maybe it needs to be adjusted again? maybe the ISC went bad from it getting washed.

 

[pj91gsx]

what is the FAIC? What does it look like?

 

[tqmx1]

what is the FAIC? What does it look like?

The two water lines lines you said you disconnected in post one . never herd of a FAIC. Your finger must have missed the V

 

[pj91gsx]

oh ok. I know what that is. The reason is because the plastic vacuum piece off of it broke. So I decided to eliminate it.

 

[pj91gsx]

What does the FAIV do?

 

[tqmx1]

What does the FAIV do?

OK DSM101 the FAIV is (fast air idle valve) there are two aprox3/8" fittings on the TB they go to the FAIV. Inside (not scrvceable) is a wax pellet when cold the pellet opens a valve valve letting more air into the intake past the throttle plate to increase the engine speed when cold. When the engine warms up the pellet expands closing off the air passage and dropping the idle back down to warm speed (aprox750/800 RPMs).

If the lines are not connected the pellet never gets warm/or takes forever and hence high idle.

The only thing plastic I see around the valve is the ICS that is on the same unit just to the left side of the FAIV.

Not having a 49stater I would have no idea what T fitting you are talking about.

 

[pj91gsx]

ok that makes sense. Im going to work on it this Saturday and I will keep that in mind.