RUNNING REALLY RICH

Please take the caps lock off. It is very annoying to read.

The stock 19 lb injectors are orange or tan.

How do you know it is running rich? Do you have a wide band air/fuel indicator? Cars without working catalytic converters will often have irritating fumes from the exhaust.

Dump the codes to find any other problems.
Dumping The computer diagnostic codes on 86-95 Mustangs

Revised 19-May-2009 to update drawing for dumping the codes on 86-88 Mustangs with no check engine light.

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the way 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. You watch the flashing test lamp or Check Engine Light and count the flashes.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

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. You watch the flashing test lamp or Check Engine Light and count the flashes.

See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical





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.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.



The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.

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.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see Digital Ford Code Reader (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

Problem is the aftermarket cam/TB/Intake on a SD car. Convert it to Mass Air. Problem Solved...

Charlie

As an alternative, you could get something to tune the EEC with, or pay to have it tuned. Doing it yourself would bably be more bang for your buck. Of course, learning to tune is difficult and time intensive. Still the rewards of tuning your own car are awesome.

just back the fuel pressure of some. thats what your afpr is for.

ShortThrow50 said:

just back the fuel pressure of some. thats what your afpr is for.

Click to expand...

Bad advice.

The computer can only compensate by about 25% total. So it can richen or lean out the fuel by about 12.5 % to each side. What he will accomplish by pulling fuel pressure is that he will lean out the rich part of his curve, but will also lean out all of the rest of his curve. For example, if he is currently rich at idle but is perfect at WOT, then pulling fuel pressure will help to bring his idle back into tolerance. However, his WOT AFR will also lean out.

Where would you rather have the correct AFR? Running rich will not cause engine damaging detonation, but running to lean definitely can. The computer will try to compensate by adding more fuel into the curve at higher rpms. However, this could take quite some time as the EEC4 doesn't change the modifiers at WOT, and the engine is rarely going to see 4-5k rpm at less than 80% load. Additionally, if the computer has already compensated by richening the mixture up top, or if he pulls more than a few psi, the computer will not be able to compensate and so he will actually force a lean condition there. That's the worst possible situation.

If, and it's a big stretch to tune this way, he has no alternative to do it the right way, then he should perform these tricks somewhere that he can be sure he isn't causing problems. Doing this on a dyno with an AFR gauge is preferred. Doing it at a track by a guy who understands what he's doing is also ok, because if it's done gradually with consistent runs, and you pay attention to the trap speed, one can ensure that they are not running the car too lean for the computer to compensate. An AFR guage, a good ear for detonation, and/or spark plug reading skills are hand when trying to attempt something as shade-tree as this. Another problem with this method is that after hours of tuning when you feel you've finally got it right, the computer will continue to adapt, and the next time at the track you'd find that the tune that was right isn't any longer.

Overall, tuning with fuel pressure alone is a band-aid compensation for a larger problem. For example, adding fuel pressure is will help to compensate for injectors that are too small - something I've done. Conversely, pulling fuel pressure will help to compensate for injectors that are too large. Still, the method clearly isn't optimal, and trying it will cause secondary issues that would concern any knowledgeable tuner.

Before you jump off and spend a bunch of $$$, spend 2 cents for a paperclip to dump the codes. Make sure you don't have a bad sensor or other simple problem before you go blowing money on a tweecer or other tuner device.