Help, No Spark - Driving me nuts!!

[BiyatchX]

94 MTX
I just replaced the following items, and am getting no spark now. The tach moves to 3-500 while cranking, and it ran when I pulled it into my garage. The 3 timing marks line up perfectly, CPS gap @ .030, ground strap hooked up and tight, crossover bolted down. I have read every post I can find on the forum for no spark and have tried most suggestions. Any help would be greatly appreciated.

Replaced:
Clutch / TOB
Rear Main Seal
Rear Main Carrier Gasket
Oil Pan Seals
Front Main Seal
Water Pump
Timing Belt
CPS
Spark Plugs
Valve Cover Gaskets
Thermostat

Thanks,
Ben

<small>[ July 11, 2002, 12:48 PM: Message edited by: BiyatchX ]</small>

 

[sdpatt]

Ben, welcome to the SHO Forum. I'm sorry to hear of your sparkless condition. Did you do the work yourself? If so, you should be very aware of the following components.

You'll need to verify all of the connections:
-Front and rear plugs on DIS module
-EEC (on firewall above CID sensor)
-CPS sensor (plug under cyl #4 runners)
-CID sensor (plug on top of cam sensor)
-Coil pack (plug on driver side)

If these are all in place, you may have to check the plugs on the wiring harness plate bolted to the passenger side rear intake manifold bracket. There are two or three plugs on that plate.

When you are cranking the engine, does the CHECK ENGINE light go out after a second or two or does it stay on? If it stays on, the EEC is not getting a signal form the CID sensor. That shouldn't prevent spark from being generated though. There is a possibility that teh CPS is not providing a signal. I know that would be ery unfortunate, but you can test it by methods provided on this site -> http://www.wellsmfgcorp.com/default.htm. The information on Hall effect sensors is in Volume 3, Issue 1.

You may also want to run the EEC self-test. Here is a great site to describe that process -> http://www.dalidesign.com/hbook/eectest.html

Keep us posted.

<small>[ July 11, 2002, 02:07 PM: Message edited by: sdpatt ]</small>

 

[BiyatchX]

Yes, I did the work myself, I always do but this one has me stumped.

The check engine light stays on. The diag codes were 111 111. The tach moves the same with the CPS unplugged, so I am leaning toward that. I did replace it, and when I check it with an Ohmeter, it and the previously working unit they measure the same across the various pins.

When I removed the old CPS, I stripped the screws and replaced them with new screws, shouldn't matter right?

Any other help is greatly appreciated.

 

[projectSHO89]

When I removed the old CPS, I stripped the screws and replaced them with new screws, shouldn't matter right?

As long as you used stainless screws!

The CPS is a Hall-effect switch. That means that it relies on the making and breaking of a magnetic field to generate the necessary switching of the output state. Standard magnetized screws can interfere with a Hall effect switch and cause it to remain either on or off.

Checking a hall-effect device with an ohmeter is not effective. You have to measure the output voltage while the magnetic field is interupted/non-interupted. You can probably do this with a needle probe in the CPS connector/wire on the top of the intake while turning the engine by hand (wrench). BTW, I can think of all kinds of safety issues if you don't have both wheels up on jackstands, since you would have to have everything connected and the ignition turned on.....

Steve

<small>[ July 14, 2002, 06:36 PM: Message edited by: projectSHO89 ]</small>