Super Coupe dies at stop lights

Hi guys. I am brand new to this site as you can see. I am brand new to Fords. I am actually a Mopar guy with a few old Mopes. To give some symptoms of this deal, here we go...

Warmed up or cold. Does not matter
A/C on/off does not matter

This thing can come to a stop light and idle fine. The other day we had not started this car in a year. It fired right to life with a new battery. I changed the oil and everything else. It idled in the driveway for I bet an hour while we washed her and waxed her. It never even ran hot. Dead center on the temp guage. Today, we actually got new plates for it and drove it on the street. It ran just fine. We got 4 miles form here,and it dies at a stop light. It ran fine, going down the road, check engine comes on, then goes right back out. Next stop light, she is fine. Engine light flashes on and off, the idle kicks to 1200 rpms from its normal 700 rpms.

The car ran good up until her stepfather changed the water pump . This was 2.5 years ago. He is a very solid mechanic and has been around the block a time or two with cars. Something happened during the water pump swap.

Now, I hate to make this long, but I need to say one more thing. When you shut this motor off, it makes a hiss down after the engine is stopped. I can almost tell you it is coming from around the intake tube and where it goes into the intake form the intercooler. But I can't swear by this. It is hard to tell. Maybe it is just vacuum form the wastegate??? What are some ideas here guys. I found a ticket from the dealership that they replaced two parts a long time ago.
Here are the parts...
FMC# F1SZ 12A297 B # ctrl asy ign multip
FMC# E98Z 12A112 A Stator Asy- (hall Eff

That is the exact way it is printed on this.Thanks, Keith

I'm by no means an expert here, but have been around here a while. Sounds like a lot of possibilities, especially the fact the car sat a long time w/out running and it idled so long for the car wash. I was always under impression not good to let car idle too long.
That aside, need to check for any engine codes since your check engine light came on.
A common problem associated with car shutting down at idle is with cam and crank sensors. Depending on what the code check reveals, you'll probably need to replace them. Cam sensor not difficult to replace, crank sensor is a little more work.
You can also do some searches on here to find out more.

Welcome aboard and best of success with your SC!

The car ran great till her step dad replaced the water pump. He is a very qualified ase mechanic. But that does not mean he is perfect. Hahah. As for the car at idle, It is better than going out and doing a burnout after it sat for a year. When I say it sat for a year, it was started every 3rd month or so. When my girlfriend parked her SC, it was doing this. We are just now dealing with it. It IS NOT related to it sitting.

Next, how do I check the engine codes on Fords? I know on my mopar stuff you cycle the key switch 5 times or something. You guys will get me going I am sure. I appreciate the help.

The idle problem is probably related to the Idle Air Control valve (IAC). It's located on the throttle body and might be gummed up by oil sludge from the PCV system. You can clean the IAC with throttle body cleaner and a Qtip being careful not to damage the diagraphm. Or buy a new one fom Ford, as some aftermarket valves are backwards.

Also coolant can cause problems with the crank position sensor. Don't understand how but it does.

Jeff

My 95 SC would die while idling at stop lights, & also throw lean codes. Turned out to be vacuum leaks at my IC tubes. These cars don't like vacuum leaks at all.

Guys, thanks. I appreciate the replies. Where exactly is this Idle air control valve? DO you take it off to clean it? Or clean it on the TB. Next, you said your IC had some vacuum leaks. I take it IC is Inter cooler , not Idle control. Thanks. I'll take a look as soon as I hear where this Idle air control thing is. I am new to Fords, so bare with me.

It's on the Throttle body and has 2 wires going to it. Do a search and you will find many referances to it and how to clean it. Also do a search for sealing the IC (intercooler). You will also find this info in the FAQ section.

Jeff

Copy that Jeff, I'll get some pics up of this car too. It is a very strong example with only 70,000 miles. Very nice paint still. I'll search for the cleaning thing and the sealing ideas.

Yes, by IC I meant the intercooler. Ford used an adhesive backed tape type of sealer for the joints in the intercooler tubing. I had just had my tubes off, & didn't get them sealed up correctly. Check for vacuum leaks everywhere, not just the IC tubes. There are numerous vacuum lines behind the supercharger, under the cowl.

OK, thanks. I have to believe it is somewhere on the front of the motor. Or the tubes. It ran great until the water pump change . So, somewhere during that WP change, something did not get resealed. Now it is my job to find it.... The beauty of dating a gal with a car...LOL Thanks

A way to check your ic tubes is spray brake cleaner where the tubes bolt up to the ic and the cars idle will surge everytime you spray.
watched my mechanic do it, its kinda cool

This is the same way Nascar check restrictor plates at the speedways just before they qualify. They makes sure they are not slipping air by the carb.

Jeff got it right, it is the IAC on the throttle body. If it makes a sighing sound after you shut it off the diaphragm has failed. You need a new IAC. Not hard to change, just the lower bolt is a bit hard to get to. And get it from Ford. You can check aftermarket, but make sure the one you buy looks exactly like yours. Most try to sell you one from standard 3.8 and they are reversed from SC's. Good luck, John

Awesome guys. I am going to dig into it. What all has to come off to get to this? I am not a fan of removing more than it needs. I have a 99 Ram with a 360, and it is so simple. Yet this 93 sure seems overly complicated with sensors and all.

Had A Similar Problem A While Back

This problem drove me nuts, and i finally hit the nail on the head, when i resealed ALL of my intercooler tubes, The car would idle fine for a bit, and then the idle would start to flutter, and eventually stall. it had all the power in the world, and showed no lose on the boost gauge.. Give this a try and let me know if it works for you...

Good luck with it!!!!!!!!!!!!!!!!!!!Tim

For future reference..

If the Check engine light ever comes on, the EEC has a code to offer. Pull the code before diving in to fix a problem. In your case, an engine stall could be due to a crank sensor on the way out. The code will say something to the effect of "missing profile ignition pickup"

I've been havin a similair problem with my 94, in that when idling, it will stall w/o warning. Fires right back up without hesitation. Won't do it with the a/c on. Only thing the engine codes said was too much fuel at idle, forgot the code number. As far as the hiss, that is normal. It is the bypass valve bleeding back the pressure into the intake tube.