LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Car Will NOT start

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Old 02-03-2005, 05:36 AM
  #16  
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Re: Car Will NOT start

You said it turns over then stops. That seems as though you're not getting enough current to the starter. You should jump directly from the battery to the starter with jumper cables. Use both ground and positive. If it rotates fine, remove the negative jumper and try it again. If it's slow now, you have a problem in the ground circuit which should have been checked before anyway. You want the ground terminal at the battery, the ground cluster on the fender and both ends of the ground strap at the engine and the frame, clean, shiney and tight.

If it slows in cranking when you don't use the jumper for positive, you need to check the battery voltage when it's being cranked over. Be sure it doesn't go below 11 volts. If it does, it is either bad or severely discharged. Be sure the positive terminal and the positive cluster on the fender are clean, shiney and tight. One thing that masks itself as other problems is a starter going bad. They will draw too much current because of internal shorting and gives the appearance of not getting enough current. This can only be checked accurately with the starter under load. BUT don't just go out and buy a starter to find out it's not the problem.

Once you have it cranking fast enough, then go for the simple items. Relieve all the fuel pressure in the schrader valve. Then cycle power on, engine off, (KOEO) then back to off, about 4 or 5 times. Then push the schrader valve to see if pressure has returned. If not you know where to go. If so, check one of the plugs for spark while cranking.

Usually if the PCM is shutting down something due to a security issue, it will light the security light or blink it. By you bypassing the relay, that should not cause a security issue. Be sure the security light comes on and then goes off during the start up gage check.

One other thing, the theft deterrent relay you jumped around is activated by the BCM. It will ground the yellow/black wire. With the key in the start position and your clutch start switch closed when pressing the pedal, the BCM provides the ground to pull in the relay. You can't really check it to ground but if you ground it with a jumper wire and it pulls in but doesn't otherwise, the proper conditions may not have been met for the BCM to pull the relay in. Or it may be wiring or a BCM problem. That wire goes to the BCM on pin C11 of the larger of the 3 connectors.
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Old 02-03-2005, 01:33 PM
  #17  
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Re: Car Will NOT start

Originally Posted by slopokrodrigez
One other thing, the theft deterrent relay you jumped around is activated by the BCM. It will ground the yellow/black wire. With the key in the start position and your clutch start switch closed when pressing the pedal, the BCM provides the ground to pull in the relay. You can't really check it to ground but if you ground it with a jumper wire and it pulls in but doesn't otherwise, the proper conditions may not have been met for the BCM to pull the relay in. Or it may be wiring or a BCM problem. That wire goes to the BCM on pin C11 of the larger of the 3 connectors.
That part confused the hell out of me.

To address my progress:
Starter does not work at all unless I jump the relay. When I dont jump the relay, It acts like it would if I did not press the clutch. I have provided a picture of the relay that I bypass to get the starter working.

Now I have a new problem, the car does not start. I know the injectors are working because I can smell the gas after I try to start it. So it must be a spark problem. I just put in a new ignition coil today hoping that was the problem, but it didnt solve anything. I have a MSD-6AL that I also tried bypassing but that didnt seem to work either. When I unplugged the MSD plug that goes into the coil the middle (negative) connector in the plug was cooked. If it was just the MSD that is broken shouldn't I be able to just bypass it and plug the ignion plug directly into the coil instead of going thru the MSD?

To bypass all of my other questions, The "relay" that i bypassed, Does it cut out the spark also? or just the starter?


bypassed relay
I just stuck a wire in the brown wire side that comes from the clutch cutoff, to the purple wire side that goes to the starter.
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Old 02-03-2005, 02:58 PM
  #18  
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Re: Car Will NOT start

First hook every thing back up that you took apart. Then get a length of wire (not too small, larger than 18-20 or so). wrap one end of the wire around the starter solenoid terminal, then turn the ignition on, depress the clutch, and have someone momentarily touch the other end to the positive terminal of your battery (this will energize the starter motor). If the motor/starter doesn’t turn over, then you have a starter/solenoid/ground/positive wire problem. If it turns over and starts then you can rule out all of the above, then you have to figure out the problem between the battery/ignition switch/starter. By doing this you are bypassing the ignition switch and all the other junk in between (theft deterrent relay, clutch start switch, theft deterrent module, and all of the associated wiring) If it turns over but doesn't start then you have more to deal with. good luck. later!

jeremy
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Old 02-03-2005, 03:51 PM
  #19  
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Re: Car Will NOT start

Originally Posted by mmmchickenboy
First hook every thing back up that you took apart. Then get a length of wire (not too small, larger than 18-20 or so). wrap one end of the wire around the starter solenoid terminal, then turn the ignition on, depress the clutch, and have someone momentarily touch the other end to the positive terminal of your battery (this will energize the starter motor). If the motor/starter doesn’t turn over, then you have a starter/solenoid/ground/positive wire problem. If it turns over and starts then you can rule out all of the above, then you have to figure out the problem between the battery/ignition switch/starter. By doing this you are bypassing the ignition switch and all the other junk in between (theft deterrent relay, clutch start switch, theft deterrent module, and all of the associated wiring) If it turns over but doesn't start then you have more to deal with. good luck. later!

jeremy
Well I know the probelm lies with the relay i provided a picture of. But thanks for the info because thats exactly what I did :-) great minds think alike lol. But now I can get the starter to turn but I have no spark :-/
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