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3.8 Liter Series II Engine will Crank but Not Start

K

kdeinv

New member
Hello,

I have a 2001 Buick Lesabre with the 3.8 Liter Series II engine. I decided to post to this forum due to the excellent discussions and assistance that has been provided to others:

My Issue: 2001 Buick Lesabre 3.8 Liter Series II engine will crank but will not start. (Heard that this condition is normally the ICM and/or the Crankshaft position sensor issue)

I have found that the 20 amp DIS (Distributerless Ignition System) fuse under the hood was blown thus the reason I did not have 12 volts on the ICM (Ignition Control Module) harness (Pink wire) going to the ICM.

Once I had the ICM harness off of the ICM Module I put in another 20 amp fuse and it blew as well when I turned the ignition to "Run" position. I was told that if the DIS fuse blows without the ICM harness connected to the ICM, that the Crank sensor monitor and ICM can be ruled out as an issue and that I must have a short to ground somewhere back in the wiring. (How do I find what is causing this issue so it can be corrected.

Can anyone give me any advice on where to troubleshoot this issue and how to do this? There are many wires in the ICM harness and many are taped up and I do not know how to check the wires to see what the issue is. I know there is a Ignition relay before the DIS Fuse. I was also going to look at the ignition switch as a possible source of the problem.

One guy online said that the Pink power wire in the harness connects directly to the DIS fuse and that I could run a wire directly from the fuse box to the connector for the power. (I would think that would not really solve the problem.)

Any advice would be appreciated.

Thanks In Advance
 


The fuse pops for a reason, so I wouldn't jump the wire. sounds like something is grounding out. Do you mean the wires are individually tapes up or just in the factory loom? Disconnect the harness, take the loom off and check for any bad wires. If its individual wires that are taped then I would get a new harness from the junk yard. Be careful of the ground wire it is short and the terminal is on the head, I think, under the coil pack bracket, with a 13 or 15mm nut.

The crankshaft position sensor is connected the harness at the crank pulley.


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Thanks for the Info.

Is it true I can rule out the Crankshaft Position Sensor and ICM if I am still blowing the 20 amp DIS fuse when I turn the key to "Run" with the ICM harness disconnected. Just want to make sure of that. I know when the ICM harness is connected to the ICM then the Crank Sensor/ICM could be the issue.

When I talk about wires being taped together I can see some taped and they also have the flexible heat shield over them as well. All from the factory.

Not sure where the physical wires all go but I know some go to the fuel injectors as well. Is the harness one long piece or separate pieces on the 3.8 liter engine. Should I just be following the pink wire on the ICM harness to see if it is grounding out?

What about the ignition switch. I know it connects someway to the overall ignition harness as well. (Could those wires be shorting as well)

I have the factory service manual and schmatics but they are somewhat hard to understand. I know there is an IGN Relay that works with the DIS and other functions. Could the relay be grounding out? But if the relay was bad then you would expect to see the Oxygen Sensor, Trans, and other fuses blow as well)

Any additional advice or comments would be appreciated. (Like how do I test for a wire that is shorting to ground and is causing the DIS fuse to blow) -
 
If you have a 12v lighted probe tester, you can test for a short to ground by connecting the probe to the positive terminal, and carefully probing the suspect wire at a connector end, so as to keep from damaging insulation. If it lights, then that wire is grounded somewhere. Be careful, however, since some sensors will not like being tested that way... I know somebody else on here knows what all is safe to test in that way...
 
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