Car people need some help.......

[jcovercash]

OK I have a

92 5.0 Mustang
5 Spd.
A few mods nothing major....

Lately when I have been downshifting it will cut off on me.
Its not that im stalling that car out, it doesnt chug and jerk. It just cuts off.

I notice it most of the time when im inn 4th gear downshifting to 1st or 2nd. I will push the clutch in and apply brakes, or apply brakes and push the clutch in, then downshift to 2nd or 1st. With the clutch still pushed in The car will just cut off. It loses all power, I just turn the key and it starts right back up.

Can anyone help me out? What could this be, Im not much or a car person and I dont want to pay a mechanic to help me figure out what it is.

If you have any questions that could possible help you help me please ask them.

Thanks,
Josh

 

[jlee]

Downshifting to first!?

That, my friend, is not good. You shouldn't ever have to downshift to first, unless you're barely moving and want to take off.

My car ('98 Corolla CE) won't let me shift into first if I'm going too fast for it (~33, I think). Same with second - I can't downshift to second at 70mph..but I can around 55. Prevents over-revving, I guess.

Anyways, all I can think of is that your car doesn't want you to break the rev limiter, so it cuts the engine..but since the clutch/transmission isn't controlled by the computer, I don't see how shutting the engine off would prevent over-revving (the car would still be in gear if you released the clutch, whether the engine was on or not).

Can you downshift from third to second?

 

[jcovercash]

Originally posted by: CadetLee
Downshifting to first!?

That, my friend, is not good.

LOL maybe i didnt make myself clear, it does it when im coming to a complete stop....

Like at a stop sign stoping with the clutch in and downshifting to 1st, to get ready to take off when its clear (The clutch is NEVER let off during the process in which it cuts off, its pushed in the whole time),
or downshifting to 2nd to slow down and wait on traffic to clear, and then going....

Its not like im going 55 and droping it to first

Josh

 

[The Stigenator]

check your PCV valve. my toyota did that at one time. Also try increasing idle a bit (if you got an idle adjustments screw).

sounds to me like your car is slowly dying.

 

[jlee]

Originally posted by: AMDman12GHz

Originally posted by: CadetLee
Downshifting to first!?

That, my friend, is not good.

LOL maybe i didnt make myself clear, it does it when im coming to a complete stop....

Like at a stop sign stoping with the clutch in and downshifting to 1st, to get ready to take off when its clear (The clutch is NEVER let off during the process in which it cuts off, its pushed in the whole time),
or downshifting to 2nd to slow down and wait on traffic to clear, and then going....

Its not like im going 55 and droping it to first

Josh

I edited just as you posted, apparently

 

[jcovercash]

Originally posted by: The_good_guy
check your PCV valve. my toyota did that at one time. Also try increasing idle a bit (if you got an idle adjustments screw).

sounds to me like your car is slowly dying.

I have a PVC valve, but nither me or my dad can find the friggin thing . Ill try looking later today and see.....



I havent really tried downshifting from 3 to 2, but i can try... It doesnt do it all the time but about 25-45%... It worries me, i dont want to lose power as i turing through an intersection ..

Josh

 

Try cleaning your AIS motor (Automatic Idle Speed).
It is a small cylindrical canister that is mounted on or near the intake manifold and has several 1 to 2 inch diameter hoses running to it.
It would also be wise to check to see if the vehicle has any trouble codes.

Go purchase a Haynes repair manual.

 

[jcovercash]

Originally posted by: Roger
Try cleaning your AIS motor (Automatic Idle Speed).
It is a small cylindrical canister that is mounted on or near the intake manifold and has several 1 to 2 inch diameter hoses running to it.
It would also be wise to check to see if the vehicle has any trouble codes.

Go purchase a Haynes repair manual.

I have a haynes repair manual..... What should i do to clean it once I have located it? Where do i check trouble codes at? Will that be in the Haynes manual??

Thanks,
Josh

 

[Quixfire]

Your PCV Valve is in the back of the engine, goes right behind the plenum. You should also change the breather filter located underneath the valve.

Besides cleaning the IAC (Idle Air Control Valve) clean the throttle body with carb/injector spray and a soft bristle toothbrush. I would also check for vacuum leaks between the upper and lower manifolds, this is a common leak on those engines.

Good Luck

Ford Mechanic (16 years)

 

I have a haynes repair manual..... What should i do to clean it once I have located it? Where do i check trouble codes at? Will that be in the Haynes manual??

On early Fords with OBD 1, you will need a analog volt meter to check your trouble codes.Go to the emissions section of the Haynes manual and follow the directions to check your trouble codes.

Once you locate the AIS motor, carefully remove the two rubber hoses (One goes to the intake manifold, the other to either the throttle body or airbox) and the electrical connector.Unbolt it from the bracket and clean the inside of it with either carb cleaner or throttle body cleaner.
Blow it out with compressed air when done and reinstall it.
Make absolutely sure that all the connections are tight.

Besides cleaning the IAC (Idle Air Control Valve) clean the throttle body with carb/injector spray and a soft bristle toothbrush. I would also check for vacuum leaks between the upper and lower manifolds, this is a common leak on those engines.

Good Luck

Ford Mechanic (16 years)

Be carefull, some Fords have a delicate plastic coating on the inside of the throttle body that will be damaged if you use any type of cleaner.These can be identified easily because there will be a large red sticker stating so on top of the throttle body.

 

[jcovercash]

Originally posted by: Roger

I have a haynes repair manual..... What should i do to clean it once I have located it? Where do i check trouble codes at? Will that be in the Haynes manual??

On early Fords with OBD 1, you will need a analog volt meter to check your trouble codes.Go to the emissions section of the Haynes manual and follow the directions to check your trouble codes.

Once you locate the AIS motor, carefully remove the two rubber hoses (One goes to the intake manifold, the other to either the throttle body or airbox) and the electrical connector.Unbolt it from the bracket and clean the inside of it with either carb cleaner or throttle body cleaner.
Blow it out with compressed air when done and reinstall it.
Make absolutely sure that all the connections are tight.

Ok thanks for all your help, I will try that later today once my dad gets home...... ANd ill let you know how it works out.

Josh

 

[Ornery]

If you don't want to crack your wallet for a mechanic, you'll have to crack it for a decent manual. The Helm manuals are really nice, because they have Ford's part numbers right there in the diagrams.

The_good_guy and Roger sound like they're on to it with the idle speed.

 

[Quixfire]

Originally posted by: Roger


Be carefull, some Fords have a delicate plastic coating on the inside of the throttle body that will be damaged if you use any type of cleaner.These can be identified easily because there will be a large red sticker stating so on top of the throttle body.

It doesn't damage the throttle body, it just may remove the teflon coating which is design to prevent the throttle from sticking from engine debris. It's clean it or replace it, the choice is yours.

 

[notfred]

That's a wierd problem. you'll get better answers at the corral

 

[LAUST]

Watch out on just adjusting the Idle screw, you want to check that the TPS voltage is right 1st I would say, if your TPS is sitting even .1 volt under you will get lean conditions as an example. If you have or get a manual it will have the Volts required for Idle. Key On for your Stang I think is .9 to 1.0 volts.

 

It doesn't damage the throttle body, it just may remove the teflon coating which is design to prevent the throttle from sticking from engine debris.

I didn't say it would damage the throttle body, I stated ;

Be carefull, some Fords have a delicate plastic coating on the inside of the throttle body that will be damaged if you use any type of cleaner.These can be identified easily because there will be a large red sticker stating so on top of the throttle body.

 

[jcovercash]

Thanks for all your help, i showed my dad this thread. Niether I nor him can find the PCV valve or the AIS motor, we have looked in the places the book showed us also.

notfred, I registered at the corral forums, and i just got my confirmation. Ill try posting there...