I searched, but I can't find my answer

[James50Stang]

Ok, so I start the car in the morning and it idles fine, but when I hit the gas, no power, and it spurts, shakes stutters and backfires. Usually, it will be like that for like 5 minutes or so, then it kicks fixes itself and runs fine.

Lately, as I've driven down highways, going about 60-65 MPH, I can feel the car lose power, and start to slow down. It's like a switch getting turned off. I dont even take my foot of the pedal, I keep it steady and it gradually slows down to the point where I have to pull off the highway because Im going to get killed. Driving through my neighborgood, it honestly feels like Im running on like 3 cyilnders. I pull into my spot, it revs around 400 rpms, and the lights dim, getting ready to stall.

I start the car up a minute later, ****ty driveability for the first few minutes, but I can easily get it up to highway speed with no problems.

I recently switched out for new plugs, wires and 02 sensors, but nothing has helped. Im swapping from an AOD toa T5 soon and I want to get it fixed so I can enjoy the new gift to myself.

FWIW, I have 3.73's, MSD wires, MSD 6A Box, Full exhaust, off-road h-pipe, cold air.

I was beginning to think today that it could be something wrong with the computer? But I just replaced that in December. What do you all think? Fuel injectors? I'm stumped

Thanks for all your help!

 

[jaymac]

run the codes yet?

 

[jaymac]

did it run fine before the MSD box?
Have you tried disconnecting the box and re-connecting the TFI?

 

[2002BLGT]

disconnect the MSD and run the factory ignition system , if that doesnt change anything get a new pickup for the distributor or just get a reman distributor ......sounds like ignition related for sure though

 

[James50Stang]

run the codes yet?

I meant to do that today, but the place I went to was too busy to help me out. I dont have the necessary tools to do it myself either. Im sorry about that, I meant to mention that in my first post.

SOmeone told me places like Autozone could do it for ya, but I went today and they said they couldn't. This sucks.

Oh, also... My motor is nearing its 200Kth mile. Do you think it could also be signs of my motor beginning to go out on me?

James

 

[jaymac]

My motor is nearing its 200Kth mile. Do you think it could also be signs of my motor beginning to go out on me?

James

My *guess* is no. You would notice things like black smoke (blow-by), large oil consumption, etc.
Autozone doen't have EEC-IV scanners for the staff. They DO sell them, for like $25ish. That will be the best $25 bucks you'll ever spend, and you will use it over and over again. It would also throw a code if the pickup mentioned earlier was the culprit.

So, first disconnect the MSD, then buy a code scanner. You can thank me later

 

[James50Stang]

The MSD was disconnected before any of this crap started. I just reconnected it this weekend. Are you talking about that little plug on the front of the distributor? It does sound like ignition to me also now that I think about it.

Ill let ya know how it all goes later. I have class tonight so I'll just hobble my steed to school, lol

 

[sunil6784]

Walmart also has a real nice one for 30 bucks.

The highway thing sounds like the alternator...When you are driving, watch the panel lights, do they go out one by one?

Also, if the highway problems just started, it is possible for the two problems to be not related.

 

[jaymac]

that depends; there's the TFI, bolted onto the distributor, that the wire harness would plug into w/o the MSD, then there's the two-wire plug coming from the same wire loom w/ a plug in it, that's your spout connector, which, if left unconnected (unplugged), would cause a slight loss in performance, maybe 3-4 tenths, but not all the prob's you're talking about.

 

[James50Stang]

it shouldnt be the alternator. the only time they noticeably dim is when i put it in park after its been running crappy. and i think they dim just because of the fact I'm about to stall my car out. i put a 130 AMP alt on in March anyway.

im excited for my T5 swap by the way!

 

[jaymac]

buy the scanner. 8.5 times out of 10, it will tell you what's up

 

[jrichker]

I meant to do that today, but the place I went to was too busy to help me out. I dont have the necessary tools to do it myself either. Im sorry about that, I meant to mention that in my first post.

SOmeone told me places like Autozone could do it for ya, but I went today and they said they couldn't. This sucks.

Oh, also... My motor is nearing its 200Kth mile. Do you think it could also be signs of my motor beginning to go out on me?

James

You don't need much more than a paperclip to dump the codes.

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.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.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

 

[James50Stang]

Ok men, I pulled codes and here's what I got.

12, 41, 91, 18 in that order

I read something about the spout on the distributor? I think that was code 91

 

[jaymac]

OK, I'll have to get my manual, but IIRC, 12 is idle speed incorrect, 41 is O2 sensor/lean mixture, and I'll have to check the other 2.
Is that KOEO or KOER? (engine off or running?)

 

[James50Stang]

KOER... only the code 12 came up for KOEO

 

[jrichker]

Code 12 -Idle Air Bypass motor not controlling idle properly (generally idle too low) - IAB dirty or not working. Take it off and clean it thoroughly with throttle body cleaner. Clean the electrical contacts with non flammable brake parts cleaner at the same time.

Code 18 - SPOUT out or wiring fault - look for short to ground in SPOUT wiring going back to the computer.

Code 41 or 91 - O2 indicates system lean. Look for a vacuum leak or failing O2 sensor.

The computer sees a lean mixture signal coming from the O2 sensors and tries to compensate by adding more fuel. Many times the end result is an engine that runs pig rich and stinks of unburned fuel.

The following is a Quote from Charles O. Probst, Ford fuel Injection & Electronic Engine control:
"When the mixture is lean, the exhaust gas has oxygen, about the same amount as the ambient air. So the sensor will generate less than 400 Millivolts. Remember lean = less voltage.

When the mixture is rich, there's less oxygen in the exhaust than in the ambient air , so voltage is generated between the two sides of the tip. The voltage is greater than 600 millivolts. Remember rich = more voltage.

Here's a tip: the newer the sensor, the more the voltage changes, swinging from as low as 0.1 volt to as much as 0.9 volt. As an oxygen sensor ages, the voltage changes get smaller and slower - the voltage change lags behind the change in exhaust gas oxygen.

Because the oxygen sensor generates its own voltage, never apply voltage and never measure resistance of the sensor circuit. To measure voltage signals, use an analog voltmeter with a high input impedance, at least 10 megohms. Remember, a digital voltmeter will average a changing voltage." End Quote

Measuring the O2 sensor voltage at the computer will give you a good idea of how well they are working. You'll have to pull the passenger side kick panel off to gain access to the computer connector. Remove the plastic wiring cover to get to the back side of the wiring. Use a safety pin or paper clip to probe the connections from the rear. The computer pins are 29 (LH O2 with a dark green/pink wire) and 43 (RH O2 with a dark blue/pink wire). Use the ground next to the computer to ground the voltmeter.

Most of the common multimeters have a resistance scale. Be sure the O2 sensors are disconnected and measure the resistance from the O2 sensor body harness to the pins on the computer.

Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter. Do not attempt to measure the resistance of the O2 sensors, it may damage them.

The O2 sensor ground (orange wire with a ring terminal on it) is in the wiring harness for the fuel injection wiring. I grounded mine to one of the intake manifold bolts