qwiketz

Hi guys. I'm finally back to working on the c4 after a busy few months at work. Here's what I have done.

replaced optispark (dynaspark)
replaced water pump
replaced ignition coil module
replaced iac
rebuilt the ecm (bad solder joints)
verified the chip file is consistent with my original
replaced the grounds from the battery to the block and to the chassis
new battery

Before the ecm rebuid I got the c41 and the fans going on as soon as you turned on the car. That is all fixed now; it seems like it's back to normal.

The car has fuel pressure at the rail (mechanical fuel pressure guage on the rail) and cranks fine. When I crank it, my wife didn't see light on the noid light for the injectors and she didn't see the light go on off the coil with the spark tester. I will have a buddy of mine come by today to help me out and reverify.

I saw a post last night that said that if you try to start the car with the A-G jumper to pull codes, I may have smoked my icm? Does this sound accurate? I went to my local o'reilly's and they don't test icm's. I know that Autozone and pep boys don't either. I have a local mechanic shop that I could probably reach out to this work week to possibly test it.

Any other ideas?

antfarmer2

How are the fuse for the injectors looking?

93Rubie

Use a test light connected to battery positive and probe end into socket of unplugged injector to test for ECM control of the injector. If it flashes your good.

Switch to battery ground and test for power at the power side of the injector connector. Does not matter which on a 92, do both banks.

You can test the ICM, Coil, ECM signal to ICM, BUT you need to understand what your doing. Your testing for CONTROL of the coil. The coil is ground side switch by the ICM. You need signal to ICM and ICM to control coil.

If you do NOT have ECM control, verify power and grounds to ECM. Ditto with proper inputs such as Opti-Spark signals.

Tom400CFI

^Good advice here. I may have a little more....


Did you reverify this? If you have no spark, and no inj pulse, the common part there is the optical pick up in the distributor, it's associated wiring, and the ECM. Ignition and inj. signals leave the ECM on separate paths (harness') so if you had spark, OR inj pulse, then the opti would have to be generating a signal, and the ECM, receiving it.

Easiest way to test for opti signal that I'm aware of is to see if you have a tach signal when cranking. This is much easier w/a scan tool with data stream, but the stock tach should bounce off 0 when cranking, too. However, if you have neither spark, nor inj pulse, there almost isn't a need to confirm a tach signal. That's a pretty sure bet that there isn't one.

qwiketz

wife got stuck at work late so not testing today. Hopefully tomorrow.

qwiketz

Hi guys. As an update, I got my icm tested out and it appears I may have fried it cranking the car with the paperclip method to pull codes still engaged. I ran it at 2 different o'reilly's and the icms I have are dead. I guess it was a $50 lesson into what not to do (don't forget to pull the wire when pulling codes).

So, time to order a new one.

93Rubie

I hope that fixes it.

qwiketz

[QUOTE=Tom400CFI;1591815261]^Good advice here. I may have a little more....


Did you reverify this? If you have no spark, and no inj pulse, the common part there is the optical pick up in the distributor, it's associated wiring, and the ECM. Ignition and inj. signals leave the ECM on separate paths (harness') so if you had spark, OR inj pulse, then the opti would have to be generating a signal, and the ECM, receiving it.

Easiest way to test for opti signal that I'm aware of is to see if you have a tach signal when cranking. This is much easier w/a scan tool with data stream, but the stock tach should bounce off 0 when cranking, too. However, if you have neither spark, nor inj pulse, there almost isn't a need to confirm a tach signal. That's a pretty sure bet that there isn't one.[/QUOTE

hooked up the battery and cranked the car. No light on the noid light and no spark coming off the coil to the opti. The tach does not move when cranking. In fact, it is below zero and doesn't move when cranking the car.

A few more details on the car. I replaced the stock opti with a used, low mile dynaspark unit. I still have my original opti. Replacing the opti required me to undo my crane hi 6 ignition box wiring. I also replaced the water pump and removed a few of the lines toward the front of the engine.

When going from the dynaspark, I had to buy a wiring harness adapter for the wires going to the opti. The 92/93 is different than the later years. The wiring plugs right in with the adapter installed. The adapter is up in the middle of the passenger side of the intake manifold side between the sets of injectors.

I tried to visually see if perhaps I could have swapped one of the wiring harnesses for the injition box but it doesn't look like I did. I printed the wiring diagram for the ignition box and will verify that things look correct. It sounds like the ignition boxes can cause some problems if they fail or wiring issues come up; I'll have to try to verify that it's hooked up correctly.

That's where we're currently at. Not much progress but I'm going to try to get back to this.

qwiketz

So while trying to research my no start problem, I saw this thread:

"The opti has two functions in the spark process. The first thing that happens is as the cam turns, the optical section of the optispark picks up the signals by the rotation of the shutter wheel. The pulses are sent to the PCM via the optispark electrical harness. The PCM processes the signals along with other sensor input and determines the proper time for the coil to fire. The PCM sends a signal to the Ignition Control Module (ICM) and it, in turn, causes the coil to fire. The spark from the coil travels through the coil wire back to the secondary ignition section of the optispark (cap and rotor), to be distributed to the proper cylinder.

If the opti is never sending the signal to the PCM, the PCM will never send a signal to fire the coil.

Here is some testing you can do. Refer to this diagram.

Disconnect the ICM connector. Leave coil connected.
Turn key to ON.
Check for dc voltage with a digital meter at harness terminal "A" to ground and and also "D" to ground. Note: Use a modern digital meter with at least 10 megohm impedance to protect the PCM (in case you measure anything in that direction).
Result should be 10v dc or more on both terminals. If you get no voltage, use the diagram and chase back toward the coil and the ignition fuse. Power for the ICM comes from the ignition fuse and through the coil, so any of that could be bad.
If you have good voltage, switch the meter to ac scale and connect test leads to terminal "B" and to ground. Observe meter while cranking the engine. You should see between 1 and 4 volts ac (those are the pulses that trigger the coil to fire).

If you don't see the proper ac voltage the problem could be the optispark, the harness to the optispark, the PCM (not common) or any of the wiring in between. Visually inspect all the connections you can get to for poor contact or corrosion.

At the end of the optispark harness (disconnected from the opti) with the key ON, you should see:

A = ~5vdc
B = ~5vdc
C = 12vdc or system voltage
D = ~0 - 0.2 ohms ground"

I checked the icm harness and the dc voltage was fine. I didn't know how to check the a/c on my meter, so that site is untested.

I checked the optispark harness, and a, b, & c are all right around where they should be.

Once again, I have a new icm and ecm. I swapped in a used dynaspark unit that appeared to be in good shape, but who knows. Prior to swapping my original one back in, are there any other tests or procdures that I should look into?

I did see the procedure of checking an optispark without installing is using a drill and connecting the harness to it and connecting it to a plug wire and plug. Maybe I could try that with my old one to make sure that it is working prior to dissasemblying everything and reinstalling my old parts.

I originally removed the opti but it was likely the ecm causing my issues. The solder was cracked in multiple spots.

Any suggestions?

Kevova

Have you ever replace jumper harness to opti? From what you are posting signal is not getting from opti to ecm. Ecm doesn't know engine is spinning. I recently read dielectric grease is not good for opti. Of course ground wires.

qwiketz

Thanks for the suggestion. Since it's a dynaspark, the harness is attached to the opti; you can't remove it similar to an oem one.

Is there any other way to test the wiring and unit?

qwiketz

update.... started tearing down the car. I'm going to swap the original opti back in but I'm going to test that it works/fires the plug this afternoon before really getting into it.


Last night I drained the coolant, removed the belts and blower accessories and undid the ignition box wiring.

I still have to finish removing the electric water pump, remove the pump housing and loosen the damper. Once done, I should be able to swap them.

antfarmer2

Put antisieze on the pully.

qwiketz

yup, I have it on there now. It's an aftermarket ati unit that I've had on and off about 4 times now over the past 10 years.

qwiketz

Hooked up my original opti as in the video and I see spark and can smell fuel. Looks like I have a bad dynaspark unit. I believe I can send it back for a rebuild so it may not be a total loss of the $300 I paid for it...

qwiketz

update - 5/30/16

so I swapped in my old opti that I mentioned that I tested in the last post. I got as far as getting the opti in; I haven't completed reinstalling all the other components.

I cranked the car but it didn't start. So, I started to test once again:

icw:
a 10.8 v
d 10.6-10.8v

opti harness
a 4.8
b 4.8
c 10.8

I hooked up an inline spark tester off the coil and it lit up. Hooked it up off #2 cylinder and it lit up twice while cranking

used a noid light on one of the passenger side injectors and it lit up twice when cranking but then went out. I did it a second time to verify and it lit twice or three times and then went out.

Since the voltage was so low, I called it a night and put the charger on the battery. The battery I have is barely hanging on. It passed the test protocol at autozone the last time, but it was low on juice since I've been doing a bit of testing and a few components on this car draw power even with the ignition off.

Hopefully, after work tomorrow or Wednesday I'll give it another try and see how it does with more voltage.

On a different note, I'm still not seeing the tach move when cranking. It's below zero. It might be moving but it definitely isn't in the positive territory. I don't recall if it was that way previously or if this is more recent to the problems.

One thing I'll need to check next time is whether the oil pressure is moving up while cranking since that will cut out the fun if it's not reading.

Any opinions or ideas on any of this stuff?

qwiketz

update 6/11/16.

With the battery charged, the car just turns over; it doesn't sputter, try to catch or anything. I verified again that there is consistent spark off the coil at at the plug. There is fuel pressure (I have a rail mounted guage) and the noid light is indicating that the injector is firing. I can small some fuel out of the tailpipe.

I thought that perhaps maybe the timing was off even though these things (gen 1 opti) are only supposed to be able to be installed one way due to the splines on the input shaft. I did my best to verify that it was being installed correctly and it slipped right into place and it was flush on the cover so I think I had it correct.

I tried to crank it over and again, same result. No backfiring, not firing, nothing. The car is showing oil pressure on the guage. Tach is moving slightly but is below 0.

I removed the opti today to inspect the rotor screws and overall condition of the opti. Here are a few photos. The points are pretty nasty, but it doesn't look too off to me (not that I'm an expert or know much at all; this is my first opti inspection).

What do you guys think? Should I toss on a new cap and rotor or do I have bigger or different problems? Also, there is gas in the car but it has been sitting for a bit. Should I try to siphon it off and put in fresh gas? I'm just surprised that there isn't even a sputter.

Kevova

Check spark plugs with all your testing and cranking they maybe fouled.looking at pictures cap and rotator don't look bad enough not to start. Looking at May post 10.8v system voltage will cause ecm issues. Attach battery charger to insure there is 12v minimum while you are testing. If battery and ignition feed voltages are not within .2v there's something causing voltage drop

qwiketz

I did try with a fresh charge, but didn't get anything. No pops, sputters or misfires. That seems like a very drastic result, even if the plugs, opti and rotor and possibly stale gas. The car has a crane hi 6 ignition box, accel coil and it still wouldn't fire. If I recall, the plugs are new but they definitely may be fouled at this point due to all the testing. I would at least have expected to hear it struggling.

Kevova

If you disconnect crane box any change? Any other extra features?