red90cobra

iTrader: (36)

Okay guys I am getting no spark and no fuel. The rails do have pressure just not spraying fuel. I have checked the ground and power to the pcm with a test light and they do have power and ground. is there anything in particular I need to look for or check out? I did the harness btw. i scanned the pcm and the map works the tps works and thermostate and iac works according to the scanner. what do I look for now besides pulling the whole harness out. any advice would be great. thanks for any advice or comments.

srun

kairles

iTrader: (1)

as k5tpi asked in your other thread have you removed VATS, also is the ECM getting an RPM signel?

red90cobra

iTrader: (36)

i thought the pcm take puts out an rpm signal? it take the crank or cam reads it and outputs the signal if not could you tell me where to check for this signal at this point i'd try anything.

red90cobra

iTrader: (36)

also i think i have taken the vats off with hpt

AceHaag

iTrader: (12)

what is your pcm out of year and model? it may help in figuring out your problem.

RFERG43

The crank angle sensor will do that to you. It is a reluctor type sensor. If you have a multimeter put it on ac voltage auto range and you should see a voltage when you crank the engine. Sorry, have no idea what the voltage should be but I would think it would be at least one volt. Might compare the voltage output with something like the vss output from the tranny.

Slo_240sx

iTrader: (17)

Definately sounds like a crank sensor. I would go over the schematics again with the right year and test.
-Alex

red90cobra

iTrader: (36)

the pcm is a 99 and the harness is out of a camero of the same year

kossuth

iTrader: (12)

First thing I would do is solve the fuel problem. Sounds like you have things wired way wrong or something. Fuel pump should at least prime when you cycle the key. I'd try to jumper across the fuel pump relay and see what happens.

red90cobra

iTrader: (36)

the pcm doesn't control the fuel pumps in my car. also the wiring is mostley the same as when i got it out of the other car. does anyone have diragram for the fuel injector connector and whats suppose to be hot also the coil packs. i'll go over the wiring again tonight. I'm sure the crank and cam sensor are working now. I see rpm when i bump the starter.

red90cobra

iTrader: (36)

also what does the vats disable? how can I check to make sure that's not it.

Slo_240sx

iTrader: (17)

The PCM should always activate the fuel pump. It is a 12v feed to the fuel pump relay, which will prime for 2 seconds and then shut off. Then when cranking it will reactivate. So you should have:

1) 2 power feeds, 1 switched off the PCM
That switched should power the coil to close the relay.

2)1 constant ground on the other side of the coil (control circuit)

4)power feed to the pump when the relay is closed.

On my car, the old setup was a ground to close the relay. I had to cut it and constant ground it then cut the control circuit power feed that was activated by the PCM.

Once you have fuel pressure I would then worry about the other problems. Jump 12v to the relay to see of the pump kicks, if not then your other relay wiring is wrong. If it does activate however then your PCM isn't outputting the 12v power feed to the relay and you either have a bad power feed (probably constant 12v orange wire) or a bad ground.

Look on your scanner again and see you have a RPM signal on the scanner. Yes the PCM does output a tach signal, but that is after the PCM converts it from the input the crank signal give the PCM. If you have no crank signal input from the sensor then your PCM will not fire the coils or the injectors. Vats also disables the injector pulse width after 2 seconds when it does not recongnize a passlock key input from the BCM. Figure out fuel then let us know. -Alex

MrDude_1

iTrader: (4)

first thing i would do would be open the HPtuners scanner, and turn the key on.

assuming i connect with the scanner, i would then watch the "RPM" gauge in the scanner and crank the engine.

if the crank sensor is on right, working, then you should see some RPM..... if it doesnt, the PCM does not realize the motor is turning, it does not fire spark and it does not fire the injectors.


also, the injectors and coils are powered off of two fuses, one for each bank.. check thoes.




thoes two things would be where id start.

kossuth

iTrader: (12)

Ok, the PCM supplies a ground signal to both the coil packs and the injectors for "fire" them off. Like we said though get your fuel pump figured out. That is a must. It doesn't matter what you are using for your pump. As for what injector wires do what do you have a wiring diagram? If not go here www.alldatadiy.com and sign up. You can get pretty much the entire factory diagram online. Anyways, your pink wires on both the coil pack and injectors is a switched hot wire. This wire must be hot not only when the key is on but when the starter is cranking too. Make sure it it hot when cranking. I've seen people make that mistake before and wonder why it won't start. Any wire for the fuel injectors that has a black tracer (IE stripe) on it then that is the ground signal coming from the PCM. Hope this helps some

kairles

iTrader: (1)

I don't get it. Does the ECM have to power the fuel pump? Will the ECM not powering the fuel pump make it not pulse the injectors?

sounds like the ECM doesn't know the motor is running/cranking. he has pressure at the rails just the injectors aren't firing.

red90cobra

iTrader: (36)

this is what i was trying to figure out also but everyone say i need to hook the pump up to the pcm. also i do get rpm when cranking. i do not get power to the injector connectors, i am going to check on that one. thanks for the help. the reason for the pcm not controlling the pcm is I have a auto rod 7 switch panel mounted on the cage. i figured i did not need to hook up the pump to the pcm. will it not run without it.

kossuth

iTrader: (12)

The two harnesses coming off the coil pack wiring should be pink on one cylinder bank and pink with a white tracer on the other cylinder bank. All the pink wires should be spliced together into the larger wire. The coil packs and injectors have the same power feed on a fbody. I think it is only a 20 amp fused circuit on each side. On my S10 I just tapped into the factory coil wiring on the power distribution block and ran both the banks off a single 20 amp fuse. Worked ok so far. Get a switched hot to those two wires and you will be closer to being in business. Also, check to make sure that none of your PCM or coilpack/injector hots are coming off a ACC only circuit. They MUST be on a ACC and START circuit. Sounds to me like something is miswired. Just gonna take sometime to track it down.

G-Body

iTrader: (4)

You do not NEED to hook the pump up to the computer, it will run just fine if you have it on a manual switch but most people let the computer decide when to run the pump because it is easier. I think it is also a safety thing too, if the engine stops running the computer will turn the pump off so if the car is in an accident and the fuel line ruptures the computer should turn the pump off.

red90cobra

iTrader: (36)

i think i might of gotten it down it cranked for a whoppin 5 seconds and died. and when i went to restart the battery was low. I'm gonna put the battery on the charger we'll see what happens tomarrow. thanks for everyones help.

Slo_240sx

iTrader: (17)

Put new plugs in it. I had that happen to me