Help With Trouble Codes...

[Mavrick]

I just built a motor and I have it running in the car.. I have a surging/missing idle, and the car likes to stall when coming to a stop sign.

Here are the KOEO codes..

These three, I am not too worried about. The VSS and Neutral pressure switch are not hooked up, due to me using a toploader tranny. I need to extend some wires to hook up the VSS (I think this is casuing my stalling problem - I read about it years ago) and I plan on looping the neutral switch. TPS I will adjust tomorrow and see if it still pops a code.

22 - TPS out of range
67 - Neutral pressure switch open
29 - Insufficient input from VSS

These three I am lost on.. could they be related to possibly a bad ground or something? The car gets lots of fuel.. my gauge says that fuel pressure is a little high (41-42lbs at idle, vac on) and the pump is fairly new, no signs of running lean or rich - the car runs great while driving. The spout thing I havn't a clue.. but the spout connecter is plugged in, I know that. Timing we set to 10* (have to e-test once i figure these codes out).

18 - Loss of tach input/spout circuit grounding out
87 - Fuel pump primary circuit fault
95 - Fuel Pump Secondary Circuit Fault

Thanks for your help,


EDIT - The car idles great when cold (open loop).. ie no surging.

 

[jrichker]

Code 22 MAP (vacuum) or BARO signal out of range. The MAP or BARO sensor is pretty much the same sensor for both Mass Air & Speed Density cars. The main difference is where it is connected. Mass Air cars vent it to the atmosphere, while Speed Density cars connect it to the intake manifold vacuum. Its purpose is to help set a baseline for the air/fuel mixture by sensing changes in barometric pressure. The MAP or BAP sensor puts out a 5 volt square wave that changes frequency with variations in atmospheric pressure. The base is 154 HZ at 29.92" of mercury - dry sunny day at sea level, about 68-72 degrees. You need an oscilloscope or frequency meter to measure it. There is no way you can use a common cheap voltmeter or DVM to accurately measure the output signal.

The MAP/BARO sensor is mounted on the firewall behind the upper manifold.

Baro or MAP test using frequency meter - run the test key on engine off. The noise from the ignition system will likely upset the frequency meter. I used a 10 x oscilloscope probe connected from the frequency meter to the MAP/BAP to reduce the jitter in the meter's readout.

If it is defective, your air/fuel ratio will be off and the car’s performance & emissions will suffer

Some basic checks you can make to be sure that the sensor is getting power & ground:
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.
Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same wire on the TPS. It should be less than 1 ohm. Next check the resistance between the black/white wire and the negative battery cablet. It should be less than 1.5 ohm.

The following power on check requires you to turn the ignition switch to the Run position.
Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or EGR sensors. Use the black/white wire for the ground for the DVM.

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

Code 87 – fuel pump primary circuit failure. The fuel pump lost power while the engine was running. Check fuel pump relay, check inertia switch, wiring to/from inertia switch, red wire going to inertia switch for +12volts. Check the other side of inertia switch for +12 volts.

To help troubleshoot the 87 code, follow this link for a wiring diagram for 89-93 cars http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp

For 79-88 cars use, http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp

Code 95 - the 95 code is because at one time or another the fuel pump relay hiccupped and didn't provide power the pump when the computer told it to run. Sometimes this is a one time thing, other times it is a no run or runs poorly condition.

To help troubleshoot the 95 code, follow this link for a wiring diagram http://www.autozone.com/images/cds/gif/large/0900823d80167162.gif

Using the diagram, check the red/black wire from the fuel pump relay: you should see 12 volts or so. If not, check the inertia switch: on a hatch it is on the drivers side by the taillight. Look for a black rubber plug that pops out: if you don't find it, then loosen up the plastic trim. Check for voltage on both sides of the switch. If there is voltage on both sides, then check the Pink/black wire on the fuel pump relay: it is the power feed to the fuel pump. No voltage there, check the Orange/lt blue wire, it is the power feed to the fuel pump relay & has a fuse link in it. Good voltage there & at the Pink/black wire, swap the relay.

 

[Mavrick]

OK well the fuel pump, spout and VSS codes were in continuos memory. Could these be related to my car stalling/being bump started (2-3 times a day)? My TFI module is new from napa, so it should not be a problem (at $100 - I hope not).

 

[jrichker]

Clear the codes by disconnecting the jumper while the codes are dumping. Run the car several days and recheck. The code 18 may be a wiring problem. The code 87/95 is either a wiring problem or a bad fuel pump relay.

 

[Mavrick]

MAP sensor wasn't plugged in, and I replaced the fuel pump relay.. CE light is now off and I got 11's when i ran the KOEO test.

Idle still surges and the car still stalls when coming to a stop.. I have to find a multimeter to double check the TPS, and get my speedo hooked up. Hopefully this will clear some stuff up.