been broke down a month

[dieselbeef]

thanks for the input..the truck is an 02. those codes were there and remain there after changing the ecm and the map sensor. also changed the vp. codes didn't change. got a ton more codes after the new ecm went on..that seemed to be the reman ecm was bad.
as I changed the new parts and they didn't resolve the problem the old parts went back on. restocking fees on this stuff is costing me a buttload of money.
I have 4.8 volts to the 5v supply going into the map sensor.
im hesitant to buy another or try another ecm. 800$.
I have a feeling the pcm is bad..but I cannot verify it in any way..for another 400$ test shot
ive chased wiring all over this truck. the wiring is pristine for its age. cant see it being that
going to take the hot wire from the map sensor to the ground on the batt and check voltage.
then the grnd from the map to the pos battery and check voltage.
I know the signal varies. checked that.
depending on the test results I will leave the hot from the map to the batt grnd and start unplugging sensors.
if this doesn't work itll be a pcm.
I spend a cpl hrs everyday working on this ...
changing the vp was off/on/off/on with the original..same results
changing the map..i brand new one was bad...took 2 days to figure that out
chasing wiring a whole day
changed the ecm...cpl hrs off/on/off/on...same results
chased the wiring under the dash and the connections at the pcm/bulkhead connections. as I take them apart evry single one gets cleaned and dielectric grease when I put em back together
truck isn't stock..hot rod vp..bigger inj...bigger turbo..intake manifold...tuners/programmers...gearing changes...6000$ billet trans

its not like I don't know my way around the truck..ive drag raced it sled pulled it and towed at 28k gross...this electrical crap is kicking my SSSSS

 

[Nesikep]

Nothing more frustrating than electrical gremlins... I would test the alternator for AC ripple since that seems to mess with things, and is pretty easy to do

 

[dieselbeef]

gonna try the 1488 tst first..then go to the alternator..this things gonna be the death of me

 

[Atimm693]

Nothing more frustrating than electrical gremlins... I would test the alternator for AC ripple since that seems to mess with things, and is pretty easy to do

That's doubtful if the code sets before the truck even runs. Alternator can't make a ripple if it isn't spinning.

 

[Farm Fence Solutions]

I'd bet a beer it's in the MAP sensor connector/wires. Continuity test end to end. Air intake temp sensor is connected to that mess.......I think. If I loose the beer, delivery is not included.

 

[Nesikep]

AtI'm. . That is true, though I didn't see where dB said codes were set before it starts.
On Mopar man they say to disconnect everything not factory... and especially noise filters.. while I will say a noise filter is only a bandaid to the ripple problem, if a filter eliminates it, it could point a finger at the source.
I'd try disconnecting the oil pressure sender just to make sure that doesn't have an internal short... 4.8v isn't bad, but usually voltage regulators are within tighter tolerances than that ... something is drawing more than it should... the million dollar question is what

 

[Kingfisher]

Just unplug the alt. the engine won't start? It sets a code while cranking only?

 

[dieselbeef]

it runs..really weak..no power/no boost...

I guess I could try the alternator unhook

gonna check map voltage and then start unplugging things...til it changes

 

[dcarp]

Have you tried going back to stock as far as tuners go. If the tuner went bad it could be the cause of your problem.

 

[dieselbeef]

no tuner on the truck