Why does my car start/stall unless I am giving it gas after I changed my manifold?

Check for vacuum leakages for the low idling.
As to the A/C etc not working and overheating, have you checked the fuses?
Did you miss out any ground circuit connections?

I am not sure; someone told me it could be a pinched wire; but I am not sure where I coulda done that

I know I hooked everything back up as it came off. Other than that I am not sure as to the grounds if they are hooked up or not; but I would suppose so. The thing is that everything worked fine before I changed the manifold. The only thing I did that wasn't by the manual was disconnect the battery.

Ground circuits are bolted to some part of the engine so if any was disconnected while removing bolts, they could have been missed out.

As to the overheating and A/C not working, it could be a blown fuse so did you check as I suggested? Sometimes jumping the gun makes you go round in circles. Always start with the basic. A blown fuse would prevent the cooling fans from working and this would result in overheating and tha A/C not working. Btw recheck the wiring connectors that you disconnected. Check if any had been interchanged. Note the wire colors.

You mentioned disconnecting the battery. That can result in low idling as computer memory is erased and needs to relearn. During this time the idling would not be stable and might stall. One way of expediting it is to get the throttle body cleaned to eliminate air flow restriction due to dirt accumulating.

I understand what you're saying; but I have hooked all things up & like I said the only thing I DID NOT DO was unhook the battery. But like I said before, I was told it could a pinched wire causing all these problems. I am just trying to figure out where I could've pinched a wire under or around the manifold. That's what I really need help with; because if that's not the problem than it is going to Pep Boys to get fixed.(for no less than $200.00)

And it not Temp gauge now working; it is Temp Gauge not working. Daggum big fingers & bad eyesight.

lol. I read it as the battery was disconnected. For the temp gauge not working, I understood it as a typo and understand the situation.

Have you checked the fuses?

Here's the thing, everything was fine until I changed the manifold; which had to be done.

Let us start with the basics. Temperature gauge first. The attached schematic shows the temperature sending unit wiring. Unplug the connector and use a wire to ground the Red/White wire. Turn ignition switch on and if the gauge works, either the switch or ground circuit is bad. If gauge works, do not keep ignition switch turned on for more than 3 seconds.

Why don't you want to answer my question?
If you do not want to answer, I would not be able to help you.

No, I have not checked the fuses because they were fine before I changed the manifold. I have also changed the thermostat & the heating sensor & the coolant temp sensor thinking those may be the issues. you're really not answering my question either............... Is there any way I could've pinched a wire in or under the manifold? i am not seeing where this could happen; but I have had two mechanics tell me that they think this is my problem

I do wanna thank you for your help; but is there the possibility of a pinched wire? That was my basic question which still has not been answered.

I keep asking if you have checked the fuses. If there are any pinched wires, the fuse would blow or the temp gauge would shoot to maximum.

Without knowing the problem how would you expect me to answer you. You mentioned there were no witres around so how can you have a pinched wire? You did not ask me if it is possible, You kept saying others have told you so. If you don't want to do it my way, the you would have to get somebody else to do the job.

Have a nice day.

I just want to know what the deal is. As far as the temp gauge I said it is not working which is causing the car to overheat. I also have to manually idle the car. But again I say that these problems were not until after I changed the manifold. I am not a dumby. I do (for the most part) know what I am doing. So again, what could have caused all these problems at the same time?
1)Very low idle (300 - 500 rpms); when it idles
2)A/c Stopped working
3)Coolant Temp Gauge stopped working
4)Start & Stall (unless I punch the gas)

A blown fuse can cause all these and you refuse to start with the basic.

Sorry to say I am not able to assist you further.

All we're trying to do here is help people in need of car repairs being uncooperative will not help here,reading it all I suggest you go somewhere else and seek help-You came here for a reason-

FYI, disconnecting the battery is a bad idea-there's a way to keep the computer memory alive at all times-Do you know this?

Hi Jess, welcome aboard.

lol. Thought I was the one who read the question wrong. Seems you too read it wrong. The battery was not disconnected.

What's this? The only thing I did that wasn't by the manual was disconnect the battery.

Thank you; but all I was asking in the first place was if there was a way I could've pinched a wire in the process of doing this; it turned into somewhat of an argument. So, when changing the manifold lower manifold on a '97 Mustang is it possible to have pinched a wire even though I have the free hanging plenum, & I see no possible way for it to happen? If so, please explain how. The reason I ask this specifically is because IO have two mechanics tell me this is what it could be; as well as a Mustang forum.

And it says the only thing I DIDN"T do by the manual was disconnect the battery

I do appreciate what he wast trying to do; but I am in need of dire help here and don't need to be talked to like I'm an idiot.

you should forget the pinched wire theory as it is not the issue. without us seeing what you did, it is a crap shoot for us to diag. please listen to these guys as they are chock full of info and we always start at basics. i would start all over again, read the posts and follow our train of thought before going off on a tangent.

Roy

If 2 other people tell you that something is possible and you don't buy it. so what difference does it make if we tell you it is too? would you accept by majority?

You don't even want to understand the basics of diagnostics so how is it possible for us to help you?

what we want to do is to get to the bottom of the prroblem and help you solve it but you must cooperate with us and give us as much information as possible. We ask questions and tell you to do specific things so that we can understand what could be the cause and rectify the problem.

If you want a staright answer as to yes otr no, ok here it is.

It is possible for a wire to be pinched. Is that what you want?

Nobody is treating you like an idiot-you just best listen and when you do, you learn like I do in here every single day dealing with attitudes and complicated car repair issues for 6yrs-You get my drift-Remember you're up against high tech professionals here-we're not backyards or partschangers we have credentials to substantiate it-Get with the program or go somewhere else and seek help-BTW there others way ahead of you that needs help too- be patient we'll get to you as time permits

I did check the fuses; that is not the problem. Next suggestion please?

Backtrack-go back and reopen the intake manifold to me it was nothing wrong with it in the very beginning-now you have created other problems- start here and keep us posted-

Let us start with the basics. I am only interested in information that would help us solve this problem.

Since there are a few problems, which are probably related to a certain extent, we have to start with something from among them.

For the low idling, check for vacuum leakage.
What was the reason for replacing the manifold?
Is the replacment manifold of the same type as previous?
Was the trrottle body rerplaced together with the maifold or was the original part reused? Was gasket replaced with the correct type and installed correctly?

Btw, which engine do you have?

Happy Father's day to all :)

I have checked for vacuum leaks & fixed 4 of them. The reason the manifold was replaced was that I was trying to replace the thermostat & in the process broke off a bolt in the manifold & drilled to far causing a HUGE hole in it. The replacement is the exact same; the gaskets came from O Reilly's. As far as the throttle body, that has not been replaced. Did not know I gad to replace that. The only issue I had was my manifold; nothing with the throttle body. And thank you for being patient with me. I have been working on this car for two weeks & just am extremely frustrated. O yeah, the engine is the 3.8 V6. And, on Monday, I did take the upper plenum back off & look and still same issue. I am almost scared to take it ALL apart again. I almost messed up quite a bit the first time. I was kinda hoping those issues would be over. Not only that; It's kinda a P.I.T.A.!

No, the throttle body need not be replaced. But since it was out, you should have cleaned. While working on it, transferring it to the intake manifold, you could have dislodged some dirt which in turn would result in air restriction and this would cause idling problem.

Get a can of carb spray and open the throttle plate. Spray into the barrel and allow to soak for a while. If there are a lot of gumb, use a toothbrush to brush it clean.

Try starting to see if there are any changes. It might take some cranking time as the carb cleaner would cause some sort of flooding, too rich for combustion.

Have you checked for trouble codes?

I have checked for trouble codes & it read my sensors; which is why I changed them, as well as vacuum leak which is why I hunted them down and fixed them. Probably wouldn't be ab bad idea to clean IAC valve either... huh? Now, please explain to me exactly what the throttle body is..... is that the piece underneath the manifold; because I was hoping not to take that out again.

Throttle body is the part that the accelerator cable is attached to. The barrel has a plate that closes fully when engine is idling but it would still allow a minimal amount of air past it. When the barrel gets dirty, this minimal amount of air is reduced and this would result in lower than expected idling.

It need not be removed for cleaning as carb cleaner works fine but if it can be removed, that would be ideal.

The IAC motor is mounted on top of the throttle body. It allows air to pass through and amount varies according to engine temperature and is computer controlled. Carb cleaner into the air passage would help to clean it. You must not submerge the throttle body and IAC while cleaning as it can damage the TPS and IAC motor.

What were the trouble codes you have and after replacement of the components concerned, are they still there?

What ever information that you have, you should provide it for me so that I can understand the problem better.

The carb cleaner can also be used to test for vacuum leakages

The codes read that I need to change my sensors; I have done this (multiple times actually). OK; what you just gave me might explain my low idle; but it does not explain why my a/c & temp gauge don't work. Keep in mind that all this quit IMMEDIATELY after I changed my manifold. Do you see why I still keep going to back to the wiring issue?

Codes DO NOT tell you to change sensors. They only identify a faulty circuit. If the fault code keeps coming back even after you have replace the component, then you need to be performing testings on the wiring circuit or the control unit.

You keep going back to the wiring issue but I am not interested in what people thinks and possibilities. What I want is information that would make me understand what could be wrong and provide a solution. I sent out test for you, did you do them?

Are you familiar with electrical testing procedures and methods?

Those things quit immediately after the repairs indicates something was not correctly installed or had been missed out and it could possibly be a pinched wire but pinched wires would blow out fuses and you said the fuses are good. They do not make sense.

I do know enough to know that a pinched wire will NOT ALWAYS blow the fuses. & to answer your question; No, I am not familiar with electrical testing procedures. I am just getting ready to put it in the shop. I came on here to get a simple answer; which at first was misunderstood. The fact of the matter is that everyone that has looked at this car &/or been explained the issues all go to the pinched wire; except you guys. Two of those were ASE Certified Master Mechanics w/ The FORD spec. I am not trying to say you are wrong; but I would like for you to exp[lain how three things all go bad at the same time & it not be in the wiring.

remember something, we are working blind here trying to help based on info that you are giving us. We all know what we are doing but without seeing the vehicle, we cannot for certain tell you much about what you did. the odds of those sensors failing all at once is not likley at all.

all the info from us guys is right on but your lack of understanding has it at a standstill. you are right to get a shop to look at it as they have it in front of them and can determine the failure for you.
wish I was more help but i bet it is something simple here but a tech will have to look at it and find the issue.
Roy

If wires had not been plugged in correctly they would not work. The fans are related to the temperature gauge as the coolant sensors are also the catalyst for them. You need to start with one and continue from there. Solving one problem might get everything else working.

It is in the wiring but I need you to perform test to understand what is missing or wrong and you keep questioning my queries.

If you want us to help you solve the problem, you need to cooperate as Roy mentioned, we are working blind.

If you want possibilities, it can take a whole day to write all of them, that is the reason I don't want to go into them because it is not going to solve the problem.

If 2 ASE certified technicians are not able to come up with anything, what makes you think the shop you are sendding it to can help you?

These 2 ASE mechanics only looked at it. They did not work on it; or even try to. They tried to tell me what to do. Here's the thing, If I knew what to do, I would've done it. If I knew how to do what they were asking I would've done it. If I knew how to do the tests ya'll are asking me to, I would've done them. I know general car repairs & GENERAL troubleshooting. After that........... I am at a loss as to what to do. I do thank you guys for all your help; but at this point, I am confused!

These guys had a look and gave their opinions and not diagnostic results without even trying to do anything but you are holding them to be true. We are trying our best to find out the cause of the problem and yet you keep avoiding what we are requesting. If you are doubting our ability to help you then you are at the wrong place.

I never like to keep anything hanging and always try to get to the bottom of the problem until I come to a conclusion, which is near if you continue this way.

If there is anything that you do not understand you must ask and let us know. There is no point for us to tell you what to do and you keeping quiet. That is the cause of all this communiction problem.

We don't have the vehicle here so you are the one responsible for getting us the necessary information to carry on. We can't be dwelling on possibiloities without checking through them.

Pinched wires do not necessarily blow fuses but it would cause something to work wrong as there would be shorting and gauges etc would go out of range.

The other thing that can cause this is disconnected components, wire harnesses, broken wires and wrongly plugged in connectors.

You are confused because you are not listening. Forget everything that has occurred and we start all over from here.

I told you to test the temperature gauge which is a simple job. Find the sending unit wire and ground it. Turn ignition on and if gauge goes to max, the wiring for this circuit.

That is the first test you need to do and what we would start with.