71chevellels1

iTrader: (13)

Im trying to get my 71 chevelle turbo ls1 started. I Have no spark, the pink wires at the coilpacks is getting juice and when i turn the key the pump goes on for 2 secs. Do I have to have a maf sensor hooked up and i also dont have a map sensor hooked up because it broke. Is this my problem? Im using stock computer with wait4me tune and wireharness.

ls1_chevelle

iTrader: (9)

If you do not have a maf, the engine will fire then shut off. Atleast with the truck 6.0l it did that.

lets see some under the hood pics!!!

lt4malibu

iTrader: (39)

are you using a test light or a meter to check for power? what kind of harness are you running?

MY67GTO

Make sure your crank sensor is plugged in. Also check your ground at the coils.

71chevellels1

iTrader: (13)

What ground at the coils? I only have the 3 grounds in the back of the driverside head. Is there more?

G-Body

iTrader: (4)

I think he means to check individually that the ground wire for each coil does in fact go to ground. (use an ohmmeter to check for a connection between the coil ground wire and ground)

Rodder

iTrader: (2)

Are you checking spark with a sparkplug or screwdriver/etc, or watching a timing light? The timing light won't fire if your plugs are fouled.

MY67GTO

The black wire at the coil connector is the coil ground. Test from that ground to the pink ign. wire of that same coil. If the test light lights, then the ign. and ground are both good. Check on both banks of the engine, because they are on different ign. and ground circuits. Disconnect a fuel injector wire and use your test light accross the 2 terminals, while cranking the engine over the test light should blink. That will tell you if the PCM is getting the crank signal.

350SS

iTrader: (38)

I would get hooked up with a MAP sensor before I started chasing the coils.

Schwanke Engines

iTrader: (1)

Have you contacted wait4me? He should be able to help you out.

71chevellels1

iTrader: (13)

Ya im waiting on the map. I think by not having it pluged in the car will have no spark. I Will get it on friday or sat so i will let you guys know. Thanks

busta9876

iTrader: (3)

engine will still have spark with MAP or MAF removed.

Coil Pack Subharness Connector Pin A, Black wire, is engine ground.
Coil Pack Subharness Connector Pin H, Pink Wire, is Ignition 12v+

Check the 3 wires at the crank sensor going to the PCM connector. If power and ground are good to the coil packs, this really is the ONLY thing that will cause a no spark condition. you don't even need the CAM sensor for the engine to run.

Crank Sensor pins A,B,C and the PCM connector they go to. C1 is the BLUE connector.

A. Dk Blue/wht - PCM C1 pin 12 - crank signal to PCM
B. Yellow - PCM C1 pin 21 - ground reference to crank sensor
C. Lt Green - PCM C1 pin 2 - 12 volt+ reference to crank sensor

Last week I went to start my 5.3 swaped caprice and had no fire...a bad crimp on one of the crank sensor pins was at fault. The copper wire pulled right out of the terminal.

Good Luck.

leonpiper69

iTrader: (3)

good question, i learned that the hard way. it was fouled plugs. only takes 2 secods 2 check um. wish i had done that first.

71chevellels1

iTrader: (13)

Put a new map and cam sensor in. Still no spark. When the key is turned on i have power on the injector plug pin. But when i turn the key i dont get a pulse so mabey i think my pcm is not seeing cranking power but should i still have spark? Crank sensor is plugged in, double checked all grounds.

jay_lt4

iTrader: (4)

where are you grounding your coil harness's,, make sure you go to a good chassis ground and dont try to ground anything to the valve cover bolts or coil brackets,,

i found out on my s-10 swap that the coil brackets and valve covers are not grounded to the engine,, the thick gaskets and the bolt grommets keep them un-grounded from the block

it will run with the maf unplugged but you will need a working map sensor

also you need a noid light to check for injector pulse, the injectors should have +12 anytime the key is on and when you crank the engine, same for the coils ,, make sure you have power to everything even while you are cranking the engine

-the pcm grounds the injector to fire it

71chevellels1

iTrader: (13)

Well i put the 3 grounds on my intake(wieand) alumium intake i just put them though 1 of the mounting bolts, after thinking there is no metal cotact because of the gaskets. I will put them on the motor and see what happens.

ls1_chevelle

iTrader: (9)

the bolts holding the intake down creates the closed loop.

-Matt

350SS

iTrader: (38)

Is your +12v source for the coils and injectors hot in run and start?

JoePZ28

iTrader: (2)

crank sensor?

MY67GTO

You will still have spark with out a MAP and MAF sensor. Check to make sure you do have 12V at the coils and injectors while you are cranking. I am not sure if the tach will move if the crank sensor is bad.