98 gst rebuild idle problems

[ohlegend]

I recently bought a gst that needed a little work. Turns out it needed a head rebuild. So I have everything put back together, but it idles at 2k. How do I properly set the idle. And what is the stock idle rpm?

Thanks in advance

I forgot to add earlier that the car had been sitting for 2 years before I got it.

 

[92AWDHX40]

Check the throttle cable it could be stock mines idles around 900.

 

[BigRed12]

Check to make sure your IAC and TPS are good. You can also adjust the idle by adjusting the screw that on the front of the throttle body facing upwards.

 

[miguelmcv]

All suggestions above are good, However, I would go with checking the cable first.

 

[ohlegend]

Ok, I will check the cable. We were moving it around to try to get the idle down to 1000~, but it would start sputtering. I have replaced the TPS and IAC, But I do not know if they are properly set. What should I look at when checking the cable?

 

[92AWDHX40]

http://www.dsmtuners.com/forums/articles-engine-fuel/191137-how-fix-your-idle-surge-problem.html

this may help too.

 

[ohlegend]

OK, I took the throttle body off and cleaned it. I also took the TPS and IAC out and made sure they were clean. I also set the throttle cable properly while the intake elbow was off. The cable is tight (no slack) when the throttle valve is closed. I have tried adjusting the BISS from closed to slightly open. The car will turn over and idle for a minute, then the RPMs will drop and it stutters out.

 

[miguelmcv]

Keep the car running till it warms up to make easy the adjustment.

Make sure the cable is not tight enough so it will keep the battle fly open, when you don with the cable adjustment, push the battle fly back against the cable to see if you can close it, if it idles down, then it means the cable is to tight, but if there is no changes, then the cable is ok.

Edit.

Forgot to say, there is a screw at the back of the throttle body, make sure the screw is adjusted, if it is way out, it will keep the battle fly open and will never close,. Make sure to adjust that one too.

 

[newtodsm97gst]

Your FIAV is shot, either block it off or try a new tb.

 

[ohlegend]

Should I Bypass or block off?

 

[92AWDHX40]

I would block it off.

 

[ohlegend]

OK I am going to buy a new BISS and O-Ring and the FIAV Blockoff plate. I should get them in a week.

Is there anything else I am going to need when I put the blockoff plate on?
I know I will have to cap the 2 coolant line going into the lower part of the throttle right?

 

[newtodsm97gst]

OK I am going to buy a new BISS and O-Ring and the FIAV Blockoff plate. I should get them in a week.

Is there anything else I am going to need when I put the blockoff plate on?
I know I will have to cap the 2 coolant line going into the lower part of the throttle right?

yes, its pretty easy but kinda messy (coolant). just block off the fiav, not the whole thing. what I meant is that don't block off the ISC.
for the coolant line, just loop it. connect from A-B so you don't have to block it off. let me know if that helps.

 

[ohlegend]

My Plate should be arriving today. Thanks for the tip for looping the coolant line!

 

[koafallenangel]

Your idle should be around 850. I have a removed balance shaft, no ac and an underdrive pulley. My car idles at 600 and operates pretty smooth.

 

[ohlegend]

I also have noticed that there are 4 lines that are supposed to attach to the intake.
1 from the BOV, then a small, medium and large lines.
My medium line is not attached to anything. Is that supposed to go somewhere?
Could that be causing a vacuum leak?

I have the plate installed and the coolant re-routed. Now I'm just waiting for the ECU to reset.

---Ok just tried to run it. It is having the same problem. Starts and dies, but now it doesn't stay running as long.

 

[newtodsm97gst]

I also have noticed that there are 4 lines that are supposed to attach to the intake.
1 from the BOV, then a small, medium and large lines.
My medium line is not attached to anything. Is that supposed to go somewhere?
Could that be causing a vacuum leak?

I have the plate installed and the coolant re-routed. Now I'm just waiting for the ECU to reset.

---Ok just tried to run it. It is having the same problem. Starts and dies, but now it doesn't stay running as long.

can you take a picture of it?

 

[97_4g63t]

From your pic. i'm guessing your vc breather hose went there. You have a little filter on the side now instead. A pic would make it easier. It should definitely be capped so no unmetered air is coming in. I would recommend just putting a hose back on. Have you done a boost leak test?

 

[ohlegend]

Ok it is the hose that wen to the vc, and it is capped.
So something interesting happened, my battery is now dead.
I have had the car started and running multiple times. It seems that the car is not getting enough spark.
I am going to try and pull the alt and take it to Autozone to have them check to see if it is bad. Which I am assuming it is because it isn't giving me enough power to run the car. Also, when I turn the car over, everything gets really dim. (inside lights, gauges,...etc) I have replaced the spark plugs (recommended NGK) and wires. I suspect either the alt or the coil packs. What do you guys think?

I have not done a boost leak test yet. I will if the alt and coil packs are good. Could someone supply a forum link to good instructions?

 

[97_4g63t]

http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/169435-boost-leak-test-how-boostpro-net-tester.html
Here is one. You don't have to buy one though. You can easily make one out of reducers or pvc. With a quick connect or a tire stem. Whatever is easiest for you. If you have a compressor with a regulator use it to regulate the amount of air going in. If you have an aftermarket boost gauge you can use it to double check and see how fast the air bleeds off. Soapy water sprayed on intercooler, piping, throttle body, bov, vacuum lines, intake manifold, brake booster etc.

 

[ohlegend]

Update: I had my alt tested and it was bad. I replaced it today. It will turn on and idle for a while and then it cuts out. I will try to upload a video to youtube for any suggestions.

https://www.youtube.com/watch?v=y0dybvVa_pE&feature=youtu.be
Here is what my car is doing

*******OK, i found a major leak just under the header, and above the turbo. The pacesetter header is not setting flush with the turbo. So I replaced it with the stock header. Now the car runs smooth for about 30 seconds and then dies out. When it dies, it gradually drops RPM and then shuts off. Any ideas?