I need some DIS troubleshooting help

what are some DIS troubleshooting steps? i know the most obvious, check for power, ground, and that the crank position sensor is plugged in. what other things are there to do to check each system on the DIS system? i read this :

quote Originally posted by ]http://www.aa1car.com/library/no_spark.htm DIS MODULE & SENSOR CHECKS Here is a little trick that will literally show you if a DIS ignition module and its crankshaft sensor circuit are working: connect a halogen headlamp to the spade terminals that mate the DIS module to the coils. A headlamp is recommended here because it puts more of a load on the module than a test lamp. If the headlamp flashes when the engine is cranked, the DIS module and crankshaft position sensor circuit are functioning. Therefore, the problem is in the coils. If the headlamp does not flash, or there is no voltage to the module or coil pack when the engine is cranked, the problem is most likely in the crankshaft sensor circuit. On most vehicles, a bad crank position sensor will usually set a fault code, so use a scan tool to check for a code. Or, check the crank sensor itself. Magnetic crank sensors can be tested by unplugging the electrical connector and checking resistance between the appropriate terminals. If resistance is not within specs, the sensor is bad and needs to be replaced. Magnetic crank position sensors produce an alternating current when the engine is cranked so a voltage output check is another test that can be performed. With the sensor connected, read the output voltage across the appropriate module terminals while cranking the engine. If you see at least 20 mV on the AC scale, the sensor is good, meaning the fault is probably in the module. If the output voltage is low, remove the sensor and inspect the end of it for rust or debris (magnetic sensors will attract iron and steel particles). Clean the sensor, reinstall it and test again. Make sure it has the proper air gap (if adjustable) because the spacing between the end of the sensor and the reluctor wheel or notches in the crankshaft will affect sensor output voltage. If the air gap is correct and output is still low, replace the sensor. Hall effect crankshaft position sensors typically have three terminals; one for current feed, one for ground and one for the output signal. The sensor must have voltage and ground to produce a signal, so check these terminals first with an analog voltmeter. Sensor output can be checked by unplugging the DIS module and cranking the engine to see if the sensor produces a voltage signal. The voltmeter needle should jump each time a shutter blade passes through the Hall effect switch. If observed on an oscilloscope, you should see a square waveform. No signal would tell you the sensor has failed.

so thats to test and determin if the ICM and coils are working or not and the CKP sensor? what things should i check comming from the ECM in the 5 pin harness to determin if it is working or not? and does anyone know the resistance specs of a 3100/3400 CKP sensor? or the specs of things that should be at each wire on the ICM connectors?

i know the wires from the CKP are POS( hi ) and NEG ( low ), but what should that voltage rating be? is it that 20mV in the reading above speaks of?

my tach does move. so does that mean that the ICM is working?


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First LX9 Fiero GT, 1987
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
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[This message has been edited by americasfuture2k (edited 12-24-2008).]

the DIS ICM and crank sensor i have on the car are the same ones that were on there when it ran last. only thing ive changed was the 7730 conversion harness. i had to build a new one due to the last one kept blowing the injector fuses. that last harness was a mess.

what things should i check other than that are connections from the ecm to the DIS
------------------
First LX9 Fiero GT, 1987
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
My Fiero Fuel Economy
Videos of My GT
Google Videos of My GT

[This message has been edited by americasfuture2k (edited 12-24-2008).]

Hello everyone,


one thing I don't like too much about the 730 conversion is the need to rewire the VSS and add a resistor/capacitor to the wiring harness. So I did some research, and well, I may have found a way to eliminate this and wire the VSS input to the "old" VSS wire the stock ECM used.

Here's my thoughts:

The 87/88 Fiero used a P4 ECM as well, and the input circuitry of that ECM (see image below -> red circle) is virtually identical to the input circuitry of the '730 (rest of the image). The only difference is, instead of using the B10 VSS input with the additional components and wire it to the VSS sensor (as described in Darth Fiero's original plans), one can use the C6 VSS input on the '730 instead, and wire it to the VSS output of the Fiero's speedometer, like the stock ECM setup. The internal ECM signal "OUT4" is used to switch between the two alternative inputs. This way the VSS wire can be moved from the old connector to the new connector just like all the other pins without additional hassle and it would make the swap easier.

To make the '730 use the "old" VSS input instead of the other one, one byte in the MEMCAL must be changed though: the address $804F (ROM offset $004F) should have bit 4 set, i.e. change the byte from (for example) $00 to $10. That should be all. The only drawback is the ECM VSS outputs can't be used with this solution, so whoever wants to add a digital cruise must use an 88 speedo to supply the 4000ppm VSS pulses.

Now, all this reasoning comes from study of the mask source code and comparison of the schematics of the 730 with the Fiero V6 and L4 ECMs, this has yet to be verified. My 730 conversion is still on hold with my V6's engine being down with a bad water pump, but maybe someone will find this helpful or interesting and would like to try this out.

What do you guys think?

Best regards,


Oliver

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Visit my website: www.fieros.de for lots of technical and other Fiero related information

[This message has been edited by Hudini (edited 12-28-2008).]

[This message has been edited by fieroluke (edited 12-30-2008).]

ive found something that has probably caused my car not to fire up. involving the DIS 7730 conversion. darth, pm me if you would like to know this if you dont already, so it can be corrected if you see it necessary. i dont want to say anything that will make you look bad. your a great helpful person. last thing i want to do is make you look bad.

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First LX9 Fiero GT, 1987
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
My Fiero Fuel Economy
Videos of My GT
Google Videos of My GT

[This message has been edited by americasfuture2k (edited 12-29-2008).]

merlot pointed out to me on the DIS connections, on the 2 pin plug, the ground, pin a, says to connect to engine ground but in the beretta 7730 diagram, it shows it connecting to BA12. thats the only one i can see off the top of my head, ill let you know more as i go along. that could be whats causing my not firing up issue. im tired....

------------------
First LX9 Fiero GT, 1987
If you can't fix it with a hammer, you've got an electrical problem
Fiero's are people too. We pay just as much attention to them, if not more than our loved ones
My Fiero Fuel Economy
Videos of My GT
Google Videos of My GT

[This message has been edited by americasfuture2k (edited 12-30-2008).]