Long story short bought a 94 V6. Starts but when revved it redlines and doesn't come down unless you shut off the engine. Car is missing one of the throttle cables (assuming the cruise cable) and I have an unknown plug I can't find where it goes any and all help in figuring this out would be greatly appreciated. The car is just a parts car so I just need the redline reving to stop so I can move it where I'm going to remove the engine without fear of blowing it tf up lol

 

try unhooking all the cables to throttle body and see if she idles

 

Also with the engine off and the air cleaner off so you can see the throttle body open the throttle body and make sure if closes. It is not uncommon for the throttle plate to get sticky. Some carb cleaner can sort it out. Carb cleaner not only cleans it also lubes up the moving parts.

Keep in mind to rev that high air is getting into the engine somehow. There are a lot of places air can enter an intake but if maxes out the RPM almost instantly that means a massive amount of air is coming in the intake from some where. Unless there is a big hole in the intake the throttle body is the only place I can think of that will let that much air in the carb.

As craby pointed out the cable could be holding the throttle plate open.

 

Did that and still got the same result, as soon as it starts the rmps take off like it floored and u have to shut it down

 

A couple updates on the situation I had the throttle body observed while starting and the butterfly valve didn't open but the high Rev persisted. Remember the guy I bought the car from said he had recently changed the injectors this made me think to check the oil and found gas in the oil. So now I'm wondering if it's high revving because it's sucking pre-emulsified gas fumes from the PCV.... I honestly have no clue at the moment as to what the hell is going on with this car.

 

pull all the injectors and make sure they are sealing to the intake. also look to see they are the right ones for your engine. as said it takes allot of air to get the engine to do this. air has to be getting into the intake system somehow. allot of air. something is not sealed or something is broken/cracked letting air in. fuel in oil is excess fuel Into one or more cylinders so it may be that one or more injectors is failing or being told by computer to dump fuel into the cylinder. has it had this problem from day one of owning the car?

 

Maybe this will help you understand.

If you have an fuel injected engine that is working as it should and you add fuel only the RPMs would drop. If fact the engine RPMs would drop and stalling would become the issue. A fuel heavy mixture does not have the power of a lean mixture. The PCM (your computer) system will not add air to the mixture. Running fuel heavy will make things dirty but it will not hurt the motor in the short term.

On the other side of that if you add air it causes a lean condition. This by itself will cause the RPMs to go up. The PCM uses the that vacuum reading (MAP sensor) and the O2 sensor to find out the fuel mixture. As the fuel mixture gets too much air the mixture burns hotter. If the PCM is seeing a too much air (lean condition) it will add fuel in an attempt to protect the engine. When you have too much air and you add fuel the results are high RPMs.

It does not take as much air and fuel as you would think to cause an engine with no load on it to rev up. What I would do is cover the metal throttle body to seal off any air for getting in. I use my hand but I would suggest using something to protect your hand like a leather glove or a flat pc of hard board or thicker flat plastic. Don’t use anything that could be sucked into the motor.

If you can start the car with the normal air intake plugged you are getting air from somewhere else. You should not be getting air from anywhere else. If can not get it to start you know the issue is with the throttle plates or the idle circuit.

 

Yeah ik it gotta be getting a ton of air, as I began digging into the car the past two days, Ive come to a few realizations. The oil smells of fuel but has a coolant contamination, Ive done a compression test and all cylinders were between 140-155, so my hunch is bad intake gasket/cracked intake manifold/plenum. I noticed a small crack on the intake plenum where the throttle body bolts on. So idk. I like the idea of checking the injectors but not sure if it'll be fruitful. N yes it did this since I bought it about 2 weeks ago. Not really sweating it too much if the motor winds up trashed I only paise 600 for the car which it has a bunch of interior that's going in my trans am. I also got tires for my Camaro as well as a nice head unit and some speakers/amp and a fender for my trans am and a spare 5speed tranny as well so I'm ahead even if the engine is shot

 

Looks like I'm getting coolant in the oil as well, check out my reply to the other guy for more details but I have a hunch that the manifold or plenum are cracked or have a bad gasket

 

Cracked intake is very rare on non-plastic intakes but it is a casting. Any casing can have a casting defect. Make sure you do not start the motor with coolant in the oil. This will ruin the motor very quickly. When you put coolant under pressure like an oil pump would be breaks down and one of the things it breaks down to is an acid. That acid will react to the babbitt on the bearings and melt it.