Long time problem, help please!!!

[Kurtis]

First of all, I know there are numerous topics regarding problems similar to mine, but after a THOROUGH search I was unable to come across anything that exactly matched my situation.

Well since the fall, my 89 5.0 has been acting up. The car starts fine (well actually, dies after first start) and after about 3-4 minutes of driving, the car just starts running like absolute garbage. I can hardly hit the throttle without the car bucking, and if I depress it enough, there are several backfires. At idle, after about 3-4 mins, the car drops a couple 100 rpms and emits an exhaust smell that leads me to believe it is running way rich. Now, the only mods I've done before this problem consisted of exhaust work. I replaced my mac o/r H with a Dr. gas X, and mac l/t's with BBK l/t's (1 3/4" primaries). I dont see how this should be a problem, EXCEPT that a tube that connected the Mac H to im guessing the smog pump is no longer installed with the Dr. Gas. Im assuming this whole problem is a result from something that has to do with the smog pump. Should I remove it? And if it is the case, why is the smog pump causing me a problem in the first place??? Is there too much fuel in the mixture? Also, is this in any way related to the car stalling at first start? And does EGR have anything to do with this?

Your help is very much appreciated as this has been troubling me for quite a few months now.

 

[MusPuppis]

Have you pulled your codes? Jrichker has made several posts with links to pulling them yourself with just a jumper wire. That will probably help track down your problem a great deal.

Off the top of my head.. When you did the exhuast you hooked the o2's back up right? It could also be a timing issue. Ive heard of the distributer hold-downs coming loose over time and causing the dizzy to spin a little.

I'd say pull the codes and post what you got. I'm betting that will zero in on the problem.

 

[jrichker]

As requested...

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

 

[gearhead81a]

Possible Idle Problem Fixes

KISS- Keep It Simple Stupid (its just an expression, you're not stupid)

Dont just panic and think it's the computer right away. Do a thorough visual inspection first. Inspect the air filter, electrical connections (everything plugged in), any loose or corroded wiring or exposed wires.

High idle is almost always caused by a vacuum leak or some other false air getting past the MAF or throttle body. Check to make sure all your vacuum hoses are in good condition. Check for cracks, dry rotting, and brittleness especially around the areas where the hoses connect to the ports. Check your intake and make sure it is in good condition and clamped on properly. Check your intake gaskets and make sure they are fuctioning as they should. If you hear hissing from anywhere, it is always the source of false air. Just spray the suspect area with soapy water and watch for bubbles.

One thing that everybody overlooks is the PCV (Positive Crankcase Ventilation) valve. If this hasnt been replaced in a while and your car is idling lousy, this is the place to start. I strongly and heavily suggest you use OEM parts and not the cheapo universal PCV's you can get at Autozone. While you're at the dealership, ask about a "PCV screen" that is located underneath the PCV valve. You can get to this with a long pair of needlenose pliers. If you have any sort of sludging problems or if you find carbon buildup anywhere, this is the most likely source of the problem.

Adaptive strategy, or lack thereof, used by late-model cars can also cause major idle problems. It recognizes certain control parameters that it has "learned" over time to make your car run right. The information is given by input sensors and controlled by output actuators. Adaptive strategy makes adjustments to A/F ratio, fuel trim, even your IAC motor to control idle. Compensation for wear and carbon buildup are the 2 main things you need to think about when it concerns your car idling properly. A big problem with this is when your battery goes dead, or if you disconnect it for a period of time (5-10 minutes), it erases all the adaptive strategy your computer stored.

If your battery goes dead and after that your car idles like hell, one of the first things you should check out is the IAC. If carbon builds up on the IAC and the adaptive strategy compensates for it, it will idle fine. When that memory is erased, the computer thinks it is brand new again. If the carbon buildup on the IAC is still present, the computer has no way of knowing it. Take off the IAC and clean it with isopropyl alcohol, or even just some brake clean. Be sure to pay attention to the orifice the IAC goes to, there might be some buildup present. Also check the throttle body for carbon buildup. Clean with the same stuff.

I hope this helps you narrow the cause of the problem.

 

[Kurtis]

Thank you for the responses thus far.

I dont have a CE light in my cluster, but I do have a test light. Thanks jrichker for the links, I now have some sort of knowledge on how to pull codes myself. So I'll give it a shot and see what shows up. If I cant do it right, Ill just bring it into my dads shop and have someone pull the codes right. Once I have the codes, Ill probably report back for help on fixing the problem, if I cant find the solution myself. Thanks again!