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Hello, I own a 1984 c4 corvette. When I’m idle, the car sounds too loud and almost like it’s reving itself like it wants to move forwards desperately. When I shift into drive, the car does a heavy jerk forward and I usually have my foot on the brakes because when i shift into drive the back wheels spin very hard. I feel as if this is unusual and if you guys have any clue what’s going on please help me out.
Definitely odd, now start simple is there anything restricting the the throttle, floor mats, is the pedal totally released.
(Sub question how are the Brakes)
If so go under hood with 10mm socket remove the whole air cleaner assembly have some or something to plug some vacuum ports. Check linkage again. If free Start the with vacuum ports plugged.Look and Listen for vacuum leaks between the intake top and intake and any other place.
Definitely odd, now start simple is there anything restricting the the throttle, floor mats, is the pedal totally released.
(Sub question how are the Brakes)
If so go under hood with 10mm socket remove the whole air cleaner assembly have some or something to plug some vacuum ports. Check linkage again. If free Start the with vacuum ports plugged.Look and Listen for vacuum leaks between the intake top and intake and any other place.
Hello, thanks for replying!
the brake lines need to be cleaned because it had sitting brake fluid inside of it. I brought it to a mechanic and he told me that I had to change the master cylinder in order to clean the brake lines?? I didn’t take his offer because I didn’t want to spend 800 bucks on that!
This really sounds like a vacuum leak to me. Remove all the vac lines from the engine and plug off the ports. See if the problem went away. If not then spray brake cleaner on the intake manifold and around the outside of the throttle bodies with the engine running and listen to see if the rpm of the engine increases when you do that. If you find a spot where when you spray the cleaner the rpm goes up then you found your leak.
the brake lines need to be cleaned because it had sitting brake fluid inside of it. I brought it to a mechanic and he told me that I had to change the master cylinder in order to clean the brake lines?? I didn’t take his offer because I didn’t want to spend 800 bucks on that!
The question of brakes was to rule out a bad Booster, for a large vacuum leak source l.
This really sounds like a vacuum leak to me. Remove all the vac lines from the engine and plug off the ports. See if the problem went away. If not then spray brake cleaner on the intake manifold and around the outside of the throttle bodies with the engine running and listen to see if the rpm of the engine increases when you do that. If you find a spot where when you spray the cleaner the rpm goes up then you found your leak.
hello, thanks for replying!
Thank you for your input on my problem! Could you give me a visual representation of where the vac lines are? I’m a beginner to my car so that would help a ton.
Thank you for your input on my problem! Could you give me a visual representation of where the vac lines are? I’m a beginner to my car so that would help a ton.
I wouldn't just pull and cap vacuum lines a noob could get screwed up real quick, first start the car listen for hiss it will have a natural one coming from throttle body with air dumping in by the injectors. If you want to now what a extra vacuum hiss is like just pull the PCV valve out of valve cover.
If you get out the 10mm socket and pull the whole air cleaner you will find a good size rubber line on the direct back if pull that it's a good reference sounds for you (also check that hose for breaks or rot) with that port on the back of throttle body sealed look for the leak hiss sound. As mentioned carb cleaner and give a little shot and suspected leak and listen for change in motor. Be careful with the plastic lines they were already bittle 30 years ago so be careful. If you break one just take a piece of generic parts store washer/vacuum hose and make splice.
Here are some images that show some of what S Carter is referring to. Loosen these four bolts and remove the two rings surrounding the throttle bodies. Two rings removed. It is not nessesary to completely remove the four bolts. Here is the PCV valve. Here are the throttle bodies to spray the carb cleaner around. Pipe coming from the exhaust manifold that the other end of the stove pipe goes to. Make sure when you replace the air cleaner base that this "stove pipe" is back in place on the base and the exhaust manifold. In the photo I just tipped the air cleaner base up against the windshield so not to disconnect any hoses. The big vacuum hose is hidden by my hand. Make sure you put this breather hose back before you put the air cleaner top back on.
Last edited by typical boomer; Oct 30, 2023 at 08:43 PM.
Reason: rearrange text
Here are some images that show some of what S Carter is referring to. Loosen these four bolts and remove the two rings surrounding the throttle bodies. Two rings removed. It is not nessesary to completely remove the four bolts. Here is the PCV valve. Here are the throttle bodies to spray the carb cleaner around. Pipe coming from the exhaust manifold that the other end of the stove pipe goes to. Make sure when you replace the air cleaner base that this "stove pipe" is back in place on the base and the exhaust manifold. In the photo I just tipped the air cleaner base up against the windshield so not to disconnect any hoses. The big vacuum hose is hidden by my hand. Make sure you put this breather hose back before you put the air cleaner top back on.
I really appreciate this!
im going to try to do this, thanks for the visual representation. Half of me is terrified to crack down on my car and half of me is excited about it haha. Like I don’t want to break anything and have to actually get it looked at.. but at the same time I want to learn how to fix my car by myself.
im going to try to do this, thanks for the visual representation. Half of me is terrified to crack down on my car and half of me is excited about it haha. Like I don’t want to break anything and have to actually get it looked at.. but at the same time I want to learn how to fix my car by myself.
Let me put your mind at ease....you absolutely will break something at some point working on your own car. You'll have that moment where you would give about anything to have a time machine to go back in time 30 seconds to right before you snapped that bolt off or broke that fitting. But if you say to yourself "No matter what I'M going to be the one who fixes this". Then the more you break the more you're going to learn. And other than parts it's a free education.
I never went to school to learn how to work on cars. Now I build engines and transmissions for fun. I got that knowledge from the wonderful people on forums like this helping me out by giving advice and just figuring it out for myself. Get a service manual for your year and just start wrenching
Do sweat yourself out if you're worried about breaking things look at this way, your afraid to break it. If you don't farm out simple look at and repair that are not over your head odds are you won't totally mangle things.
otherwise some guys who's out to beat book time may be a little rough.
Idle too high!
