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Discussion Starter · #1 ·
Hey there...i'll go on directly to the point:thumb:...i have this trouble with my shadow, when i turn my car on in the mornings, there is rough idle...what can it be? i changed the spark plugs, oxigen sensor,coolant temp sensor, map sensor, fuel filter, air filter and thermostat...what else can it be? its a 1993 2.5 tbi manual shadow. thanks in advance
 

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Is there a lot of humidity, dew, in the morning? Start by using a spray bottle with water and spraying the ignition and underhood components with the water to try to duplicate the condition. You may find a wire/ignition coil arcing to ground from the moisture.
 

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Discussion Starter · #3 ·
Is there a lot of humidity, dew, in the morning? Start by using a spray bottle with water and spraying the ignition and underhood components with the water to try to duplicate the condition. You may find a wire/ignition coil arcing to ground from the moisture.
well mostly its dry all day...and the cables were replaced also, so i wouldn't think it was that... my guesses were maybe something to do with fuel delivery like the injector or the pressure regulator...??? maybe the pump is not giving out the required pressure? another thing to notice is that theres black smoke coming out and excessive fuel consumption...what do you think?
 

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Black smoke changes everything.
High Fuel Pressure, Problems with the Map Sensor or Coolant Temp Sensor Circuit.
When I was working on these cars on a day to day basis back in the late 80's TBI cars had numerous problems with the MAP sensor and the problem was on the Baro side and it will not set a fault code. When you first turn the key on the controller reads atmospheric pressure and the readings were incorrect usually resulting in a no start due to flooding and fouled plugs.
They also had problems with injectors. The low pressure TBI injector is a ball and spring injector as opposed to the pintle used in the high pressure MPFI and the ball would not completly seat, it would actually bounce causing an extra spray of fuel.
I would start with the Map and Coolant Sensor Circuits. Be sure you have 16-20"HG at the Map at idle and check the voltage on the MAP and CTS.
The voltages are in a "sticky" in the "engine management" section titled "voltage tables".
Unfortunatly you cannot see the barometric pressure the controller is seeing without a scan tool.
All fuel control is based on the difference between Atmospheric pressure and Manifold pressure.(MAP, Manifold Absolute Pressure)
The easiest solution would be if you could locate another Map sensor and plug it in.
Just remember that black smoke is extremly rich so the plugs may need to be cleaned/replaced even if they are new and smell the oil to be sure it is not fuel diluted, change it if it is or it may wash down the cylinder walls.
 

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perhaps you have a injector that leakes down into a cylinder overnight? have you examined your plugs? they will tell you whats going on inside yer engine. is it isolated to one cylinder, or all of them? dont throw parts at it. your wasting lots of money
 
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