2G Need help rpm issue (97 gst)

[DSM NE]

Ok so about 2 months into owning my 97 gst and the car was amazing the first 4 weeks of owning it and the previous owner had done some mods to it you can see them on my profile long story short I wanted to get a new radiator fan from mishimoto got the plug n play and it blew tons of fuses a30,a40 and a50 because the connection is wrong anyway and then the cold weather came around and the car started to idle mind you I unplugged the hose to the radiator to put the new fan on and now I have replaced iac valve cleaned egr valve since I can’t find one tried to adjust tps sensor and adjusted biss screw nothing seems to work it’ll rise in rpm when idle and it will stay at high rpm while driving once I let foot off of the gas pedal like it’s stuck and so I took it to two o Riley’s and one advanced auto parts scanner said it was a o2 sensor b1 sensor 2 I also knew because my car has been running super rich I can smell gas and everything and air fuel ratio gauge can’t seem to find a balance always bouncing between 16 to 28 and just yesterday while car was at idle I disconnected the tps sensor and the rpms slowly were dropping slowly but once I plugged it back it started to rise and my apexi gauge said I was on throttle about 8-2% when my foot wasn’t even on the pedal does this sound right tps and o2 sensor is what is causing my issue? Also checked for leaks nothing boost leak tested 3-4 times nothing and yeah water pump is getting replaced right now so I need help any help hopefully those two sensors once replaced and re adjusted will solve it

 

[DSM NE]

It’s the amount of throttle you are putting down

 

[AWD-Tony]

I don’t think it’ll affect anything. Try to figure out what that 1.8% is and make sure the tps is properly adjusted. Think the link is in one of the earlier posts. The throttle cable isn’t too tight?

 

[DSM NE]

Welp a lot of pressure it idled all the way to 2300 and one of the clamps let go now it’s leaking antifreeze

 

[AWD-Tony]

Get that fixed and see if the 1.8% goes up when you press the accelerator

 

[DSM NE]

Welp I don’t have my tps adjusted correctly also the cable has some slack I’ll try adjusting tps without playing with cable first then if it don’t work I’ll play around with it

 

[AWD-Tony]

You want a LITTLE bit of slack on the cable and the gas pedal...minimal

 

[DSM NE]

Ok I’ll update you tomorrow thanks for helping out so far I appreciate it

 

[DSM NE]

Well rpms are a little bit more controlled it idles at 1200 but also when I parked the car and turned off the heater since my head gasket is blown and is causing my coolant hoses to have a lot of pressure I turn on heater to release pressure when I turned it off it started to idle surge to around 1400

 

[DSM NE]

I am pretty sure only the coolant seals on head gasket are damaged since it isn’t touching my engine oil but the weird thing is the car isn’t overheating but then again there’s white smoke water out of tailpipe and I put the coolant hose from the jug into a soda bottle of water and it bubbles a lot

 

[AWD-Tony]

What brought the idle down? Does sound like a hg but make sure that’s what it is. Do a leakdown test with the radiator cap off.

 

[DSM NE]

Tps adjustment to .62-.63 volts but once running we put the heater on to release pressure of off the coolant hoses so that they wouldn’t disconnect and leak what If I adjusted tps to 55?

 

[DSM NE]

Also the heater would also help rpms stable since it releases pressure from the hoses

 

[AWD-Tony]

Do you have ecmlink? If not follow this link

https://www.dsmtuners.com/threads/how-to-adjust-the-throttle-position-sensor-tps.324431/

Look up 2g BISS adjustment and make sure it’s set properly.

Turning on the heater pulls heat from the coolant system via the heater core. It has nothing to do with coolant pressure and or bubble. The heater core is basically a small radiator that’s located in the cabin.

 

[DSM NE]

I don’t have ecm or DSM link or anything like that also my biss screw is in pretty bad shape it’s dry and kind of cracked from the head if I screw it in more the idle gets higher so I leave it a little bit out.

 

[AWD-Tony]

Here’s the biss adjustment procedure.

http://vfaq.com/mods/BISS-2G.html

How bad is it cracked?

Obviously you have a bigger issue with the hg. That’s should be fixed first.

 

[DSM NE]

No not the head gasket the head of the screw that’s why I ordered another one

 

[AWD-Tony]

Didn’t you say your overflow is bubbling?

 

[DSM NE]

Yes the tiny hose from the coolant jug to the main radiator hose will throw pressure or something because we put it in a soda bottle of water and it bubbled more then usual cars but I think it’s only my coolant seals of head gasket because it doesn't touch my engine oil and the car doesn't overheat

 

[AWD-Tony]

You recent had the water pump replaced. Maybe it just needs bled.

 

[DSM NE]

Maybe I don’t know the coolant hoses get so much pressure it’s insane but there’s white smoke and water on tailpipe right now car is in the shop getting water pump fixed because when it got back it came back with an oil leak so I took it back to them also the car doesn't boil coolant

 

[BadRabbit]

This was a fun read. The cooling system is likely over pressurized because you are getting engine combustion into the cooling system from the head gasket leak. I would stop worrying about the idle and fix the head gasket issue before anything else. While the head is off, take the time to clean the throttle body inside and out, replace all the gaskets you can find and look into a tuner or a data logger.

No matter what adjustments you are making right now, the car isnt going to run right with a blown head gasket.

 

[DSM NE]

Ok the car is going to a mechanic next week for the head gasket

 

[DSM NE]

This was a fun read. The cooling system is likely over pressurized because you are getting engine combustion into the cooling system from the head gasket leak. I would stop worrying about the idle and fix the head gasket issue before anything else. While the head is off, take the time to clean the throttle body inside and out, replace all the gaskets you can find and look into a tuner or a data logger.

No matter what adjustments you are making right now, the car isnt going to run right with a blown head gasket.

This was a fun read. The cooling system is likely over pressurized because you are getting engine combustion into the cooling system from the head gasket leak. I would stop worrying about the idle and fix the head gasket issue before anything else. While the head is off, take the time to clean the throttle body inside and out, replace all the gaskets you can find and look into a tuner or a data logger.

No matter what adjustments you are making right now, the car isnt going to run right with a blown head gasket.

Head was rebuilt no more pressure is being made and fiav was deleted since that’s what was causing the idle much appreciated for all the help and reply’s