3.1 has a bad missfire

[terrysmonte]

hello everybody, i new to the game here. i have researched the forums and would like some insight. for starters i recently aquired a 99 monte 3.1,it was not running. it had and still problems. first, the guy told me that a shop told him it needed lifters and that was why it was misfiring , he had someone replace the lifters, long story short the guy put the wrong pushrods in the wrong place and bent some valves. i got the head reworked, everything back together, the car starts but it misfires like hell. checked fuel pressure had 18 lbs on the rail, changed pump now have 46 lbs, put new plugs and wires on it, ac-delco plugs. still misfires. where do i go from here? now the ses light comes on and blinks intermittenly, i know check the codes, dont have scanner or access to one, parts store that scans is 40 miles away, dont want to drive it that far. i just thought someone may have some insight . any help would be greatly appreciated. thanks terry

[mjc79]

check your plug wire routing and make sure they arent crossed somewhere.

[Superdave]

sounds like it could be a bad coilpack or possibly bad fuel injectors.

you can check the injectors pretty easy with a multimeter, they should be all around 12 ohms across the contacts. if any are too far off from that then i'd replace them.

to test the coils, remove all 3 and use a multimeter to compare across the seconaries (posts) of each, then do the same with the primary side (you might have to use a paperclip to get inside the holes). Coilpacks are pretty cheap usually but new injectors are expencive.. used at the junk yard are usually $5-$10 each or free depending on how honest you are.. lol

[terrysmonte]

i have put 3 known good coil packs on it off of my 95 riviera 3.8sc. i believe that the wires are in the right position. prior to changing the coil packs and wires there was the old factory parts and they were numbered 1-6 both coils and wires, but i will double check. is there a way to pull codes by jumping the diagnostic connector with a jump wire?

[terrysmonte]

also is there a way to access the injectors without pulling off the plenum?

[mjc79]

i have put 3 known good coil packs on it off of my 95 riviera 3.8sc. i believe that the wires are in the right position. prior to changing the coil packs and wires there was the old factory parts and they were numbered 1-6 both coils and wires, but i will double check. is there a way to pull codes by jumping the diagnostic connector with a jump wire?

if you had a laptop and the software/plugins you could , but without a scanner there is no way on an obd2 vehicle.

also is there a way to access the injectors without pulling off the plenum?

not really unless you got toothpick fingers lol.

[terrysmonte]

its giving me the obd2 codes p0122 and p1635 any help?

[mjc79]

the po122 code is for your tps sensor, means its reporting too low of a voltage to the computer. so you might need to get that sensor checked to see if it actually has a short in the sensor itself or maybe a wire might be bad in the wiring harness or possibly a bad pcm.

the p1635 code could mean a few things. computer usually sets off a p1xxx code when something else is wrong with some other componet. it could have to do with the tps sensor or may not. does your car have that goofy tire pressure reset button in the fusebox on the side of the dash or is it in the factory radio? could be one of your tires are low and its kickin a code out for it as well.

i'd go ahead and have that tps sensor checked to see if its bad, if it is replace it and reset the codes to see if that p1635 comes back. if it dont your in good shape. most shops or auto parts stores can test the voltage of your tps sensor to see if it fails or not. hope this helps some.

[terrysmonte]

ok got it going on all 6 except for a rocker noise, ran great. put some lucas oil stabilizer in it , ran for 15 min, killed it. tried to restart no compression on any cyl. wtf? am i going crazy or are the engines b/s