po 300 code help

[Ramsey]

i put the stock injectors in ,then i took the ones out of my escy in it and the same deal .i do wonder if allen tuned for stock inj or tuned the 60s that were in it bn unaware i was putting stock in.seems to be loading up at idle and then sure enough the cel po300 comes on.i really wonder if my intake tube is too small ,and not giving enough air at idle or not mixing right wen i slow down and stop at a red light .im stumped.im sure its the smallest of things.

[Ramsey]

alright for now ,does anyone know if allen shuts off the monitors in the tune or not ?seems like it ,wen i clear my cel i go right to the monitors and it says no monitors showing ,wich is great for now that means i can get inspected.but usually u have to do a drive cycle on it and by the time i drive 40 miles or so the lights back on.the truck is running ok but skips alittle at idle and kicks the code wen i sit at a red light ,it really doesnt bother me.so do we know this?thanks.

[Ramsey]

hellooo?

[farmtruc]

i'm not at the shop, but i'll check it tomorrow. if the truck had 60lb inj in it and was tuned for stockers, and vice versa, the truck wouldn't even run, so that's not an issue.
a p0300 is a misfire code as you know, a physical misfire, one that you can feel, is not usually tune related. an actual misfire you can "feel" and get to happen at a brake stall, is a misfire.
which means, a plug is bad/cracked (which is doubt), a fault plug wire (start it up at night and see if you can see a spark on the plug wire), an intermittant short or open on the injector wires, or it could be a coil or wire to the coil.
a tune isn't going to help with a misfire, an actual misfire is caused by something on the engine, the tune or pcm does not cause a misfire, the pcm will detect a misfire and let you know there is a misfire.

you mentioned it drives ok, then not, then good, then bad, check the wiring.

if the truck is misfiring at idle (which is kind of hard to tell sometimes), sometimes you can measure the heat on the header (if you have headers) and determine which runner is cold.
a manifold is alittle hard to do.

wiggle wires, if it comes and goes, that's a start.

you changed so much, so go over everything and triple check all the wiring.

if the truck is running, the tune is fine, especially since you said it ran good at once or occasionally, which indicates a wiring issue.

good luck,
allen

[Ramsey]

hey ,thanks allen .i dont mean to be a fingerpointer at all,i just dont know what else to do .ive had a doubt all along if i wired the inj properly or not but ive color coded all them five times and theyre fine,i think lol some of the colors are faded.but im sure they lay were theyre supposed too..but thats not saying that theyres a loose connection inside the shrink tube ,correct?i changed the plugs,changed the injectors also.by the way ,went from 60s to stock,fyi.i definately feel it at a stop with foot on brake,and i can feel it get worse wen i sit at a light for along time just before the cel comes on.like i said im just not sure .the boots on a couple of my wires do rest on the header but no melting going on.new wires also.changed coils with another set ihad .my only concern in the tune was air fuel mixture maybe causing lean or rich condition that may be telling pcm to add or take away fuel causing misfire,just guessing.when you say check wiring what wiring speciffically would i check for concern.were you talking plug wires or like inj wires ,coil,grounds etc?you mentioned all but quoted [check wiring],lol i got lost.lol. so bassiccally if i find a cold tube then its that cylinder i should run through.my worry is its random multiple misfire.so it wouldnt always be cold and ide have to find it by .coincidence ,right?if this helps today i got a po174 cel that said lean on bank 2.watcha think of that?and bank 2 is pass side right .ide really appreciate youre help bud ,and thanks for responding because i wasnt getting many .lol.and do not think i was fingerpointing cus like i said im just out of thoughts.and just dont know.take care .

[Ramsey]

ttt

[Ramsey]

ttt

[Ramsey]

hmmmmmm,hmmmmm .lol

[farmtruc]

hey, none taken, just wanted to make sure that a misfire is caused by something wrong with wiring or mechanical. if the a/f ratio is off, that's because the pcm is doing so because of a sensor, the pcm will only do what's it told to. if there is a false lean condition due to a bad o2 sensor, it'll add fuel until the issue is resolved, causing a rich condition, just as example.
did you start it up at night and see if you can see any spark across the header from a wire?
if a cylinder isn't firing, it will be colder, so check that, go ahead and grab each one after it's at normal operating temperature, haha.

ya, there could be an open on the connections you made for the injector clips.
if the pcm set a P0174, that's a lean condition, caused by a bad o2 sensor or vacuum leak, or a bad maf. that would be the side to check for cold cylinders, the ltrim value on that side/bank is probably +25, so there could be an issue on that side.

it's too hard to go over all the wiring, but each wire needs to be ohm'd out to ensure connection.
but all the wiring needs to be gone over that deals with coils and injectors.
test each A side of the injector (that's the hot side) make sure power is there.
the other side, B , make sure there is connection to the pcm be ohm'n each wire.
swap your coils if you have a spare set.

that's a start, that should keep you busy, because it's a pita to do.

[Ramsey]

thanks bud gonna do it all today,haha.gonna try.ill keep u posted,thank you.