86 SD 5.0L problems

93 LX

Founding Member
Jun 2, 2000
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Norwalk, CA.
Engine runs rough, rich and stalls. KOEO codes 22 and 18. 22 is the BP sensor which is disconnected at the moment. This is the only way the engine will run for any troubleshooting. Plugs are black and with BP sensor connected engine floods. Tested regulator with vacuum pump and it holds 20 hg vacuum. Tested EGR with pump and it hold vacuum and opens and closes. Engine stumbles at 5hg, passage seems clear.

Tested fro vacuum leaks with hoses but found none. Checked engine vacuum when running and it is over 25hgs. What does this mean? Should be lower like my 93 Stang I take it.

Any ideas? I am ready to junk the car.

Allen
 
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no I mean BP sensor not MAP. This is a Speed Density EFI.

Its not the BP sensor I tested it on my 93 and it ran fine.

BTW here is the code I got. The is from this site. http://www.troublecodes.net/Ford/eec-iv.shtml

22 Manifold Absolute Pressure/Barometric Pressure Sensor Out Of Self Test Range

18 Spark Out (SPOUT) Circuit Open
or Loss Of Ignition Diagnostic Module Input To PCM/SPOUT Circuit Grounded
or Spark Angle Word (SAW) Circuit Failure (1.9L SFI)
 
just wrote this on a dif thread.

22 - KOEO: check Vref voltage to battery NEG key ON, should be about 5v. if so, check Vref voltage to NEG of sensor, should be same. if not, perform voltage drop test on ground circuit. if you have 5v, check sensor voltage should be 1.59 at sea level, 1.56v at 1000 ft, subtract 0.03v for every 1000ft elevation.


18 - Continuous: disconnect coil plug, disconnect ECU. measure resistance between Coil NEG and Pin4 on ECU. is resistance between 20,000 and 24,000 Ohms? if not, service circuit. if so, check resistance between Pin4 and Pin40, Pin4 and Pin46, Pin4 and Pin60 is resistance over 10,000 Ohms??
 
The BP sensor is disconnected. Its the only way the car will run. It does run extreamly rich and when the BP sensor is connected it floods out. Again the sensor is good. I ran it in my 93 without any issues.
i was thinking maybe the Fuel PR is bad. Although it does hold vacuum I was wondering if it was just not wokring at all and dumping fuel.

BTW the coil is good too. Tried it in my 93 as well.
 
the first part of 22 and all of 18 check circuits(the wiring). have you run those tests??

No since your post is at 9 pm my time.

Why would it run rich then and flood out?

Also ifI pull the charcole canister vacuum line it runs just fine albetit with a higher then normal idle. I can even plug back in the BP sensor too.

Allen
 
i looked on the wiring diagram for the 86 and it shows a MAP sensor not a BAP sensor. do you have a vacuum hose hooked to it?? if not try hooking manifold vacuum to it. if you do have one hooked to it then check for 15+ inches vacuum. the 93 uses a BARO(simular to BAP) it does not use a vacuum line.
 
No since your post is at 9 pm my time.

Why would it run rich then and flood out?

Also ifI pull the charcole canister vacuum line it runs just fine albetit with a higher then normal idle. I can even plug back in the BP sensor too.

Allen

the MAP tells the computer what engine load is and adjust fuel accordingly(as well as using other sensors).

have you had a chance to test the fuel pressure??

unplugging the line caused a vacuum leak so that would lean out the mixture. have you tried plugging the hose that you disconnected(engine side) to see if it still runs good?? if it still runs fine you may have a fuel saturated charcoal canister, also.
 
On a SD car the MAP sensor (not seeing a BP sensor on the 86 wiring diagram) is the main sensor for the computer to determine what the engine is doing. You say the car deosn't run with it plugged in. This sensor needs a vaccuum line from the intake to function properly (Manifold Absolute Pressure).

When you unplug this very important sensor, the car is running off of known values.

When you plug it in, the car tries to run in closed loop using the O2 sensors along with the other sensors (MAP, IAC, ECT etc).

If the car stalls because you plug in the sensor, that doesn't mean the sensor is bad, it changes the way the computer runs the motor. One of the sensors that is involved in closed loop operation could be to blame.

Id start by seeing if you can get it to run with the sensor plugged in long enough to get some codes. You say it is running rich, first things i would check would be the ECT and the O2 sensors themselves as they play an important role in the air/fuel management in the computer.
 
Allen,
Again, please create a sig with the major mods to your motor.
We need to have this info...

Your SD car does not have a BAP.
The BAP and MAP are the same sensor (they are the same part number from Ford).
The difference is how they are used by the ecu.
An SD ecu is expecting to see pressures from the Intake Manifold.
A MAF ecu is expecting to see pressures from the Atmoshpere.

Make sure your MAP sensor is plugged in AND is referencing Manifold pressure via the vac line to the Intake Manifold.

I'll let you confirm that the sensor is hooked up properly before continuing...

jason