I need help, please. I getting frustrated with my car. After it got fixed for hunting idle and then high idle problems, now it idles high in park and neutral only. It idles about 1000 after a drive. like I stated before, only in drive and neutral. I turn it off and back on again and idles fine. Took it to a mechanic and he replaced a several vacuum lines. Another problem I have is that my cars ac only blows thru top defroster vents. It used to blow thru ac vents before. She runs really great with new injectors and tune up.
Iroc has new bosch type 3 injectors, plugs, wires, cap, rotor, o2 sensor, egr, cts, tps, iac and 195 degree stat.

Thanks,
Gerry

 

For your A/C problem, it could be the divert doors in the heat box...under the passenger side dash area. Could be a problem with a stuck vacuum door.

 

Thanks for reply 85FBTranam.

One question how how they close. The last time I used ac couple months the air was blowing from ac vents.
Anybody else, I need help with the idle issue. I've gone through the site, but there's a lot of dead ends. Members not really saying if they found solutions or not.

 

vacuum is what oppens the blend doors. It could have broken the vac. line going to the dash causing the high idle.

 

Thanks for reply's,
I found the vacuum lines from egr sol is not hooked to the egr and the other line going to the the front of throttle body is broken. Above the egr sol right side of the distributor there a t connection with 3 vacuum lines hooked up to it. the bottom line is disconnected, where does it connect too? Could they be the cause of the ac problem and high idle in parking and neutral?


Thank,
Gerry

 

Yes, quite likely.

 

Man this sucks! I hooked and repaired vacuum lines and started car. The car's idle is good, but when I drove it the car felt forced under accelaration. I unplugged the vacuum line under the throttle body and drove better. The high idle in park and neutral is still there even with the line to the throttle body hooked and unhooked. The ac still blows from the vents and the hacv line looks intact. Is the ecm suppose to throw codes with egr unplugged? The ses light on the dash lights up at start up. A mechanic I know doesn't know for sure, but he thinks its the ecm. What do you guy's think?

Thanks,
Gerry

One more question. I couldn't find a connection to the t fitting vacuum line next to the dizzy on passenger side. The connection on the bottom is the one in question. Please help!

 

You would not get an EGR code from just cranking and idling the car. It takes some driving around to get that.
It's normal for the CEL to light up during key-forward & start-up.
Once running it is off.

You may need to spend a good bit more time tracking down all of your vacuum sources and lines, then make sure you do not have any vacuum leaks.

It's really hard to get more specific with suggestions since I don't see where you've told us what exactly you're working with yet.

 

Thanks 305sbc. I've driven it for a geat deal deal time since car was put back together. I've checked lines a whole lot, guess checking again wont hurt. What do you think about the car running a whole lot better without the throttle body line hooked up?

 

You are not supposed to run with open vacuum lines.
I have to assume it is an open port since you said that you unhooked the line, but you didn't say that you plugged the port on the TB.

Above, i was trying to say that a much better description of your car than "blue iroc" would be very helpful. I don't even know if you have a MAF or MAP system, what engine or induction you have.


One thing you can try is to plug every single vacuum port on your intake, plenum, and TB. Don't drive it like that, just start and idle to see if difference in running.
If problem still there, then you can use a can of starter fluid or an unlit propane torch to check for vacuum leaks other than the lines (which are all now unhooked).

You really need to positively eliminate the possibility of a vacuum leak from the lines first before moving forward with troubleshooting. These cars are old and the vacuum lines easily crack and break. It is often hard to see a vacuum leak visually. That's why you use another fuel to test. The starter fluid or Propane will cause the idle to change when near the source of the leak.

I'm concentrating on vacuum leaks first because you have already reported seeing damage to the lines, and the symptoms are also consistent.

 

Why the new EGR?
Did you go through the procedure to set your minimum air-rate when you installed the IAC?
Did you then next install the TPS and set the closed-throttle voltage properly?
What brand O2 sensor did you use? Hopefully not Bosh, - they are known to cause problems, even brand new.

 

305sbc, man I forgot to describe car. Its a stock 89 tpi 350 maf iroc. No heater, heater core was eliminated years ago found coolant on passenger side floor. I wasn't aware that lines were not connected, but ran a whole lot better. I'll go ahead and check tomorrow and keep you posted, its dark and my lamp doesn't work. Thanks man.

Thanks,
Gerry

 

I'm trying to get iroc running as best I can. I have limited knowledge about cars, but i'm trying with help from you guys and a local mechanic. New egr was installed when new injectors and everything else was installed a couple weeks ago. I think its a bosch 02, crap. That the only thing that is not ac delco. O2 sensor doesn't throw a code when its disconnected. Man this really sucks. Thanks for your input.

 

Wheres my head. Egr is still original piece. What I meant was that a new FPR was installed. Mechanic said he set idle at about 600 in drive and tps at .54.

 

Yeah a lot of people grab those Bosh O2 sensors when in the parts stores because they are often a few dollars cheaper.
I'm not sure what the deal is with them exactly but they commonly have issues.

It's also fairly common for folks to have problems after replacing an EGR valve. It is often not an exact replica of the original and can possibly cause problems by leaking EGR into the intake at the wrong time, when it should be sealed closed. If you run out of other options, that's one more thing to look at. Removing the EGR valve and installing a block-off plate for temporary testing would eliminate that possibility of EGR leaking.

Sometimes stuff like this can come down to something very odd that you would never think, like a crack in your cruise control vacuum reservoir (magic ball), or a worn out diaphragm inside your brake booster.

 

I doubled checked vacuum lines, everything looks ok, but the vacuum line that once connected to heater valve is missing. I had it capped off when heater valve was removed. I cant find it, maybe somebody yanked it off. I knew where the line was, but never bothered to see where it came out of the firewall. Can somebody post a picture of it. I found some but pictures werent that clear.
Could this be my cars the source idle and air condition problem?

 

I was able to fix my car, just thought I woud share with other members. I went ahead and replaced ecm this afternoon after work. It idles great in all gears. I'm not done yet, I still have to press on gas pedal really quick to bring down rpms down after a drive. After that it idles normal. What can I do to fix this problem?
I also have to fix ac control vacuum leak. I cant seem to fins vacuum line that connected to heater valve. I guess I can remove ac controls and cap line from there, right?

Thanks for the help guys,
Gerry

 

The fix depends on the cause.
When it's idling high pop the hood and grab the throttle lever and see manually pushing it against the stop brings the idle down. If it's getting sticky then the spring may not be enough every time.

You can use any full manifold vacuum source for the heater valve.
You will need the vacuum for the control so your heater functions will work.

 

Thanks, i'll check on that today. Vacuum source, excatly from where? I'm learning something new everyday.

 

Full vacuum source is from the plenum.
there are ports in the rear of the plenum for this.