Possible vacuum leak?

[hashi]

So im having a problem with a rough idle and today i changed out my TPS and my ICV spark plugs and wires and cleaned out the ICV and yet still have a rough idle but i have noticed that on my throttle body there is a hose going from the break booster to the throttle body and rite above that hose there is another whole that has seemed to be plugged with something from the previous owner the picture i have attached is not my picture but the whole on the throttle body in the picture is the same whole that is plugged on mine im just unsure if that other whole should have a hose going to the break booster as well thank you all for the help!

[adjmcloon]

I think mine is like that as well

[hashi]

I think mine is like that as well

im just worried because it looks like the previous owner filled the whole with some type of silicone or something along those lines!

[vpilarrt]

Some late model M20s have 1 vacuum line running to the brake (not "break" booster) and some have 2 lines with a check valve between them. It has to do with build dates that I don't remember off the top of my head. With 1 line (like yours) there should be a plug in the upper port. If you suspect you're getting a vacuum leak there reseal it.

[hashi]

Some late model M20s have 1 vacuum line running to the brake (not "break" booster) and some have 2 lines with a check valve between them. It has to do with build dates that I don't remember off the top of my head. With 1 line (like yours) there should be a plug in the upper port. If you suspect you're getting a vacuum leak there reseal it.

im just at a lost of idea to fix this rough idle. If i barely tap the gas peddle the car will almost die. I have replaced most of the common things that can cause that for the most part. If anyone has any ideas please feel free to join in. Thank you.

[jlevie]

There are so many places to have intake leaks that you can't inspect or diagnose except with a smoke test. Have one run and fix the leaks it reveals.

[hashi]

There are so many places to have intake leaks that you can't inspect or diagnose except with a smoke test. Have one run and fix the leaks it reveals.

I just took a look at the TPS plug and it looks like it has some type of build up in it. Not anything along the times of corrosion but more like a gel substance and i also dont see a difference in the idle with the TPS plugged in and unplugged. Not sure if that has anything to do with my situation?:sad::sad:

[hashi]

I think after i get a different throttle body i'm going to check for spark and a clogged injector this may be causing a some what misfire. After that i will check the fuel pressure regulator.

If there is anything els i could try someone please chime in.

Thank you.

[jlevie]

Unless there is something else wrong with the throttle body, you don't need to replace it.

[adjmcloon]

Check your main throttle boot (the big one) in the creases of the smaller hose. You should take it off to check it, I found a split in mine only after I could freely inspect it. Also check your crank case vent hose from the valve cover to the throttle body housing. The ends can get cracked and broken over time.

[hashi]

Check your main throttle boot (the big one) in the creases of the smaller hose. You should take it off to check it, I found a split in mine only after I could freely inspect it. Also check your crank case vent hose from the valve cover to the throttle body housing. The ends can get cracked and broken over time.

Thanks for the input i changed my fuel filter today and when i took the old one out the fuel that came out was pretty much black is the only way i can describe it. Car idles better now but when on the freeway its fine too but its when i let off the gas and push it again the car seems to spit or sputter for a sec then is fine at constant throttle pressure. I'm thinking dirty/clogged injectors? What do you guys think?

[jlevie]

Thanks for the input i changed my fuel filter today and when i took the old one out the fuel that came out was pretty much black is the only way i can describe it. Car idles better now but when on the freeway its fine too but its when i let off the gas and push it again the car seems to spit or sputter for a sec then is fine at constant throttle pressure. I'm thinking dirty/clogged injectors? What do you guys think?

That and the lack of difference in idle when you unplug the TPS sounds most like an intake leak. Though a bad idle switch in the TPS will result in no change of idle when the TPS is disconnected.

A smoke test will tell if and where there are intake leaks. That should be your next action.

[hashi]

That and the lack of difference in idle when you unplug the TPS sounds most like an intake leak. Though a bad idle switch in the TPS will result in no change of idle when the TPS is disconnected.

A smoke test will tell if and where there are intake leaks. That should be your next action.

Yeah that is going to be my next step. I'm pretty sure my idle does not change when the TPS is unplugged, cant remember off the top of my head the past couple of days i have been doing a'lot to this car haha. But of course i'm still going to clean my injectors because they are most likely dirty as hell.

[E30_fiend]

Hey fag.

You know you can text me about this shit right??

[hashi]

Hey fag.

You know you can text me about this shit right??

I did know this but i thought you were just going to give me a joel watson answer for example Me - "hey joel care to help me with my car since i help you with everything" Joel - "its a m20" thats all he said lol