Damnit man, SO far I've been trouble shooting the crap out of my newly purchased mustang. Its a 1988 GT 5 speed.

Ok here are the symptoms.

1. On idle it idles at 1000 rpm. But WAIT! when I begin to turn the wheel the idle automatically begins to jump between that and 1300 rpm. And as soon as I stop turning the wheel it stops?

2. As soon as the car reaches operating temp. the idle bounces between 1k- 1500k and stays like this for sometime an than goes away and goes back to 1k. Over a long period of driving the car than becomes a tad harder to shift. Nothing too serious just begins to do it once its running for a long period of time.

3. When first turned on, certain times I have to give it gas it keep it alive and once it holds it's rpms it idles and stays on fine.

4. When I am putting it in first gear I have to give it alot of gas to keep it from dieing upon accelerating with the car.

5. Burns a crap load of gas, I know its a 5.0 but I traveled lets say about 120 highway miles on a full tank of gas and already needed to fill up. Thats crazy!

It doesn't over heat but the temp does go above normal and 1 bar before H. So I can already guess thats the temp sensor which I am replacing.


What I have done-

Flushed motor, changed oil to royal purple, added new coolant, changed spark plug cables, changed spark plugs, cleaned the throttlebody abit using seafoam, searched for any kind of broken vacuume hoses but to no success maybe I'm not looking hard enough.

Things I will do -
Change PCV valve
Unbolt the plenum off, look around for any hard to see hoses, change the plenum gaskit.
Seafoam it

I'm just completely stomped. The car pulls off launch. Hard, and its a nice 1988 Gt 5.0, the exterior is a 7/10 and interior 10/10. I Love the car I really do but I'm so stomped on these problems I'll be force to sell it if I can't get it right .

Last question is the pcv valve. Does anyone have an exact location of where it could be at? I searched on the mechanic's booklet I bought and it shows for a 4 cylinder .

And lastly, a good vacuume line where I can slowly pour the seafoam it to effectively make it to the complete intake system.

Thanks in advance, I'm so stomped I'm going to try again this weekend, I really need someone to guide me here. I want to take it to a reputable shop here in Louisiana, but the way people are charging for labor alone here is insane!

 

#1 - As you turn the wheel your power steering pump starts working harder and then your engine has to work harder to keep up with the load

#2-3 - Check for vacuum leaks. How long is a "long" period of driving?

#4 - Adjust your clutch cable.

#5 - Make sure your tires are full of air. New fuel filter or air filter, check for codes.

Check all of your EGR lines, the vac tree on the firewall, and the vacuum ports on the back of the upper intake plenum. Is that seafoam crap aerosol? I'd never put anything in my vac system that can potentially clog it.

BTW, wtf is Irractical?

 

PCV valve is located directly at the middle of the rear of the engine. stand in front of the motor and reach straight back from the distributor, over the intake and down the back of the motor...

 

I know about the power steering pump and how it works harder, but this is actually a little more than a few rpms that it would normally do. When I turn the wheel the idle starts jumping up and down is how I meant it and obviously when I center the wheel it goes away.

2. a PERIOD of driving I'd say about 20 min before it begins harder to shift to gears almost like it doesn't want to go in. But it still does.

4. I'll look into my clutch cable.

5. Tires are good on air, they would have to be terribly flat for me to get that kind of gas mileage an they arent unfortunatly. I'm "Thinking" that having terrible vacume leaks can cause poor gasmileage. I guess my question is this, is there anyway to perhaps finding a picture of the engine bay that shows where vacume lines of this particular car are located? I've searched high an low for something like that as well

Thanks for the replys and support.

Ps. I don't even know why the hell I spell it "irractical" lol oops

 

Here is a fox body vac diagram. Not EXACT, but pretty damn close. Hasn't let me down with my 91 hatch.

http://www.veryuseful.com/mustang/te...uumDiagram.jpg

It is from this huge technical wiring/vacuum information page.

http://www.freewebs.com/mustangtechl...umdiagrams.htm

After drag racing last year I was too lazy to stop at a gas station to fill up my rear tire air. Maybe 10 psi and it makes a world of difference on gas mileage.

After the 20 minute "period" of driving your trans fluid could lose whatever viscosity it has left due to temperature rise. Is it the stock trans fluid?