No Spark HEADACHES

[tepes]

1991 cutlass supreme 3.4 has zero spark, i have changed the ICM after following the testing here

http://easyautodiagnostics.com/ignition_gm/ign_module_test_2.php

i have 12 volts from the ignition to the ICM and ground is good, crank sensor is showing a reading of .600 per the test instructions at the link above.

Changed the engine computer today, still no spark.

i am in a serious bind, we had a premature son born in march and is hospitalized 2 hours from us, our honda odyssey tranny went out, our ford econoline is out of action so im really needing the communities help to sort this.

thank you in advance from a father in need.

Tim

[CNCguy]

Tim,
The DIS system only requires power, ground and a good CPS signal to create spark. Even with the 6 wire connector unplugged, the DIS will still fire. Most likely, the CPS is bad and needs replaced. Although it's not a common problem, I have seen loose terminal connections cause problems.


Congrats on the birth of your son.

[Superdave]

the CPS should read 980 ohms across the 2 terminals, it's the most common cause of a no spark situation. Take your time getting it out, if it breaks off you'll have to drop the pan to push the rest through.

The 2nd most common is a failed ignition module, you can pull it out and Autozone will test it for free.

[tepes]

thank you for the tips, this morning i rechanged the ICM with another new one hoping the previous was defective, still no spark... ive had a few friends suggest testing changing the coil packs, theyve both had exerience with GM packs failing and getting zero spark. is it possible 1 or 2 packs have failed? any ideas on how to test the packs?

i do have a new CPS here but im unsure if its beyond my skill level to change, and taking it to a shop is just not affordable at this moment..

are there any articles on changing the CPS and any tests i can do to the coils.

and thank you sincerely for the help.

Tim

[CNCguy]

Tim,
Odds are that all three coils would not die at the same time.

I don't know of any articles but my experience has been that getting to the CPS is the hardest part. Only one plug and one bolt to remove the sensor. If it is rusted in the hole it can be really tough to get out. I've had good luck removing the bolt and soaking the CPS with penetrating oil. Gently twisting while pulling straight out with some more oil will usually get them out without breaking.

[geoffinbc]

To change the CPS you remove 1 bolt on the side of the block and pull it out gently. It maybe cracked and thats why it is not working. If you break it completely in half you will have big trouble getting it out.

To install the new one just make sure the hole is clean and pop the new on back in and tighten the retaining bolt and plug it in. Try and start the car and you will know right away if it was the problem.

[bob442]

The crank position sensor is between the block and trans, and the best way i can think of getting to it is from the top, or pulliung off the Passenger side tire and inner fender, or jacking up the car on jack stands and going from underneith. the sensor should be located in the middle of the block with a thermole insalation covering the wires. should be a 10mm bolt holding it down. Good luck!

Bob

[tepes]

can anyone give me the exact procedure on testing the coil packs off the car with a multimeter, either i have 2 failed coil packs or im not testing them right.

thank you

tim


EDIT:
Coil Packs tested fine. ill be changing the CPS in the morning

[tepes]

finally got around to pulling the CPS, the replacement is a lil different as far as length and on top is a metal tab that the old one doesnt have. is this normal? here are the links to the parts

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Crankshaft-Sensor-BWD_20474698-P_762_R|GRPSENSAMS_1069532610____

https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=ECHCSS109_0176814488&An=599001+101991+50052+2052017

the one that came out doesnt have that bent tab on top, so im unclear if it makes a difference.

im going to wait for confirmation from a member here before reassembly, dont wanna get it all back together to just have to tear it back down.

thanks in advance.

Tim

[Z3500]

Unless the old one broke, they should be exact same length. That metal tab is what holds the sensor to the block, so yes, it has to be there.

[pocket-rocket]

The metal tab is the aftermarket equivalent to the hold down molded into the plastic on the old one. It doesn't make any difference on that.

As far as the "bent tab on top", I don't understand what you mean, unless it's the part on top of the connector that holds the harness connector so it doesn't just fall out while going down the road.

They look the same and look like a decent replacement for a bad OEM sensor (but Advance wants half as much $$$).

[tepes]

here is the old one

http://imageshack.us/photo/my-images/805/dsc00985o.jpg/

http://imageshack.us/photo/my-images/845/dsc00986z.jpg/

[Z3500]

Like pocket rocket said... the metal tab is just the after market hold down for the bolt to hold it on, the same as the plastic tab.

I just got a CPS yesterday, it is just like the ones you have links to, should be fine. I even double checked the part number and it appears to be the one you need.

[Superdave]

throw the new one in, it's correct (and stronger than the GM version)

[tepes]

finally cleared a few hours to toss this in, purrs like a kitten now.

thanks to all