few questions

[nickjc13]

i bought a titan 4.6 stroker from a guy that has put about 5000 miles on it. the only catch is that it has been sitting outside for two years with a garbage bag over it. i brought it home and thoroughly cleaned it. the motor was obdII at the time so i switched over all of my accessories and sensors to make the motor obdII. i kept the 99+ intake manifold. i have a stock tb and poweraid throttle body spacer. i installed 24lbs ford injectors. when i start it it will blow out a black oil/watery substance out of the tailpipe. it is also blowing black smoke. i have installed an adjustable map sensor and a afr gauge. when i go wot it bogs down and the afr gauge shows all the way lean. but when i pull spark plugs it is covered in black soot. i installed a new o2 sensor. still no change. also it will die at redlights and the afr gauge will go all the way lean if i dont catch it and rev it up a little. also it will idle up and down. any ideas?

[yuppiexj]

make sure the map sensor is getting a vacuum signal.

On my obd1 I cracked the vacuum line and it ran like crap...super rich barely idled, sooty exhaust, balck smoke.

o2 sensor does not match what the engine is doing.

[nickjc13]

how can i check if its getting vacume. i have checked it but im not sure if it is cracked or not.

[yuppiexj]

I replace the plastic tube with a piece of Stainless steel brake line cut and bent to fit. (it doesn't break like 20yr old brittle plastic)

To check MAP function, start it and then unplug the vacuum tube from the MAP sensor. if the idle quality changes (i.e. it shuts off, or runs like crap) then it is getting a signal.

To properly check map function with key on and engine not running.
a ground (farthest from vacuum nipple)
b signal
c power supply (closest to vacuum nipple)

a-b should be 4~5V
a-c should be 4.5-5.5v

when running
a-b should be a lot less than 4-5V (somewhere around 2.2V for 14 in/hg)
a-c should be 4.5-5.5 V

if the a-c voltages are low, check your ground circuit to the engine.
If the running and not running a-b voltages are the same the sensor is either bad or not getting any vacuum.

HTH

[nickjc13]

i found out that the map sensor was getting no vaccum. i re did the lines and now it is running better.

[gradon]

GJ

[SilverXJ]

I love easy fixes.