5.0 Way too rich need help!!!!

[mudnsnow]

Here my problem.

When i start my 5.0 Ranger in the morning the engine run way too rich. The engine misfire on a lot of cylinder(Run very rought). When the engine begin to warm up the engine stop misfiring but still run very rich.I think the misfire stop when the cpu enter in closed loop. I've checked a lot of thing but i've found nothing wrong.

Fuel pressure 30 psi(regulator have 1 year)
Ignition timing is ok(10 degree)
Engine Coolant sensor brand new.(last week)
o2 sensor replaced last year
No KOEO
1 KOER code(42 Lack of heated oxygen sensor switch, Rich bank)
I have gas in the engine oil.(run very rich)
At idle on the gas analyser the engine run around 1000 ppm of HC and the truck have a very bad gas milleage(less then 4MPG).

Anybody have ever run throught this problem. Or someone have an idea what to check next ????

All the engine/trans/wiring/sensor came from a 89 Bronco FS 5.0L MAP system(no Mass air flow)

 

[240cubes]

it very hard to understand you wrote

 

[mudnsnow]

Sorry but i don't talk very often in english....

When i start the cold engine: Run really rought(misfire). Black Smoke.

When the engine temperature begin to rise(CPU enter closed loop).less black smoke.Run OK

Fuel pressure OK
ignition Timing OK
Collant sensor NEW
02 sensor NEW
On the gas anyliser HC are very high(around 1000 ppm)(Max is 120ppm)
Code 42KOER (system too rich)

Tomorrow i will try a new MAP sensor.....Hope this will solve my problem

 

[240cubes]

did the MAP sensor work? did you do a complete rebuild when you did the motor swap?

 

[mudnsnow]

I don't have any code about MAP sensor and in 1989 Datastream is'nt available on my scan tool. No i don't have rebuild the engine before the swap. 180 000 KM on the clock....find in junkyard.....

 

[pro94]

Here my problem.

When i start my 5.0 Ranger in the morning the engine run way too rich. The engine misfire on a lot of cylinder(Run very rought). When the engine begin to warm up the engine stop misfiring but still run very rich.I think the misfire stop when the cpu enter in closed loop. I've checked a lot of thing but i've found nothing wrong.

Fuel pressure 30 psi(regulator have 1 year)
Ignition timing is ok(10 degree)
Engine Coolant sensor brand new.(last week)
o2 sensor replaced last year
No KOEO
1 KOER code(42 Lack of heated oxygen sensor switch, Rich bank)
I have gas in the engine oil.(run very rich)
At idle on the gas analyser the engine run around 1000 ppm of HC and the truck have a very bad gas milleage(less then 4MPG).

Anybody have ever run throught this problem. Or someone have an idea what to check next ????

All the engine/trans/wiring/sensor came from a 89 Bronco FS 5.0L MAP system(no Mass air flow)

it sounds like either you dont have heated o2 sensors or the circuit that heats the o2 sensors up when you first crank a cold motor is not working. o2 sensors dont work cold. thats why its running rich when its cold and runs better warm. they are heating up and starting to work and tell the engine that it is fat and needs to lean out. heated o2 sensors warm up real fast when you crank up the cold engine. to keep that fat idle from happening.

 

[mudnsnow]

I've replaced the MAP sensor, No more misfire occur. But it still too rich(code 42) I will look at the ckt that heat the 02.

 

[Mutant Pony]

IAT (Intake air temp sensor)?

 

[mudnsnow]

O.K. here it's around -30 Celsius......... But i've finnally found the problem...I've kept the original vaccum hose going to the MAP from the Bronco. The hoses measure about 2 feet long and i've mounted the MAP sensor lower than the intake. The vaccuum hoses was frozen near the intake.

 

[bottledgt]

a hose being froze wouldnt be a problem...unless there was water in it