leonpiper69

iTrader: (3)

why wont this thing run?

yesterday it would fire on the pass side now i have no spark anywhere ( all 8 coils). my injectors are working, plugs are soaked.

i put my timing light on each plug wire and got nothing.

then i hooked up the diagnostic port and hooked up my scan tool (cuz the stock gauges have the check engine light on) and the only codes i have are for the low fuel tank pres and the evap stuff. and it appears that every sensor is sending a signal i checked all the ones i could on my matco scanner.


i have no clue why it won't run, i actually am giving up now.

would anyone want to buy an piece of garbage motor that cant run?:ban g:

Schitzo

iTrader: (6)

who did your harness. Sounds like a bad connection somewhere.

leonpiper69

iTrader: (3)

its a factory harness and it ran fine last week? went to show it to a buddy and now its dead?

cherryelky305

iTrader: (2)

Where are you located, I'd be willing to come pick it up and take it off your hands.

86 Silverado LS1

iTrader: (2)

True that! Do you need any help picking up the trash?

Rodder

iTrader: (2)

There's probably a specific troubleshooting procedure for this in the factory service manual... but here's what I can tell you from looking at the wiring diagram...

First thing, kill the fuel the pump so you don't dump any more gas in the cylinders while you're troubleshooting the ignition. Next, work on one coil at a time. Start at coil 1. You said you've checked the wiring before, but it sounds like you must have missed something, so here's the procedure I'd use... Coil 1 has 4 pins you need to test. For pins A and D, connect a 12V test light (bulb, not LED--you want something that'll actually draw some current) between pins A & D and make sure the light works. If it doesn't, you have a power or ground problem. Now try cranking the engine and make sure it stays lit while the engine is cranking. If it doesn't, you are running off of ACC power instead of IGN power (or somehow have a '67 ignition switch). If those are OK, then disconnect C2 from the PCM and check continuity (OHM meter) between pin C at the coil connector and the following: pin 26 of PCM C2, ground, and 12V--it should be under 1ohm to pin26, and infinite to ground and 12V. If those are OK, discconect the other three coils and check continuity between pin B at the coil connector and the following: pin 60 of PCM C2, ground, and 12V--it should be under 1 Ohm to pin 60, and infinite to ground and 12V.

G-Body

iTrader: (4)

Hmm, thats weird. I don`t think it would be a PCM going dead, because there are 8 drivers in it to go bad and it would seem pretty unlikely that they all died within a few days. Same for the coils.

My first instinct would be power or ground, but you already checked those. Next up would be a sensor maybe? Can you see the cam/crank pos sensors function as you crank and scan it?

If nothing else I`m ready to go dumpster diving.

rao

iTrader: (18)

Race you to that dumpster

Keep at it - ultimately it will turn out to be something simple, it usually is.

lt4malibu

iTrader: (39)

when i first tried to start my swap it had no spark... came to find that i only had 4v going to the PCM while the ignition switch in my mustang was in the CRANK position, so i bypassed the switch temporarily and it fired right up... id definately check power/ground to the pcm.

george88gta

iTrader: (3)

We had a similar problem on my sons WS6. Reading thru the shop manual, you had to crank the engine for at least 20 seconds to get the crank position sensor code. Wire was broken right at the sensor connector.

z2fast8

i'll buy it for sure if u dont want it anymore

jomomma

iTrader: (39)

noid lights work great to see if injectors are working!

samdogmx

iTrader: (14)

ill come get it tonight, if your serious....lol

67rsss

iTrader: (4)

If you were a bit closer, we would swing by to help get it running, but IL is just a bit out of reach. Keep at it. Our killer was a broken wire at the MAP sensor. Looked fine, but it wasn't. It is most likely something silly that will really get you pissed when you find it, but you will find it if you are patient.

leonpiper69

iTrader: (3)

im getting pissed because i have no patience.

injectors are working (lots of fuel on plugs and can feel them clicking while cranking)

at present the wiring is directly connected (temporary)

i can't scan the crank/cam sensors (i cant even find them on my list of sensors in the menu, im still learning how to use this tool) but i have cranked repeatedly, at least 20 sec and no codes other than the 2 i mentioned


i hope it is simple cuz i cant find it yet and im starting to throw things (next i'll get my gun and shoot the damn car)


rodder thanks for the input, im going to try that tomorow i thought i checked everything because i have a good 12 volts at the coils (ea.) and good grounds, i also have continuity from the drivers on the pcm to the actual coils, but i have not checked the way you describe.

i just found one wire not connected (and it never was , but it ran before)

c101 plug

pin H - blk/white stripe ground

does anyone know what this goes to and is it needed?

G-Body

iTrader: (4)

I know that it is a ground and should be grounded, but I cant remember what it goes to. Gimme a couple minutes

Slvr00Bird

iTrader: (2)

Does it act like it's going to start right when you let off of it? Or does it sound like you hit the throttle sometimes while cranking it even though you don't? Violent shake while cranking??? Mine had these symptoms and it was the cam sensor going out in it... It would start, but then die when I threw it in gear. I was told that it could be that, or the crank sensor.. just my personal experience, hopefully it helps.. good luck and keep your head up, you'll get it

G-Body

iTrader: (4)

I looked it up and that wire should already be grounded, it is intended to be the ground for the fuel pump relay. It goes to a splicepack within the harness where it ties into the rest of the computer grounds. If you check it with a meter it should read that it is already grounded, if it does not, then your PCM is not grounded. You could also just ground it, theres no such thing as too many grounds.

george88gta

iTrader: (3)

Just for clarification, what I meant to say was that you have to crank the engine continously, for at least 20 seconds. Time it, 20 seconds is a long time.

andrew69_04

iTrader: (148)

ya sounds like a simple power or ground issue to me. you said you have things temporary wired, maybe you should perminently wire it how its supposed to be and tne try to work out your problems. if you accidentally hooked 1 wire up wrong, it could cause a whole lot of problems and you might just be overlooking it. hope you get it solved, that beer will taste great once it makes noise!!