What else should I check? (no spark)
12-26-03, 06:29 PM
#1
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What else should I check? (no spark)
Things I've done (can't get a spark from leading coil)
Replaced the coil
Replaced the "electronic" stuff under the coil
Replaced the ECU
Replaced the wires/magnet inside the CAS
I'm out of ideas. What else should I check? I get 12v from the black/yellow wire leading up to the leading coil, and get no voltage in the green/yellow wire. Grounds are good.
Also, the clutch switch (under dash, the switch that will close/open when clutch is pressed), I had to "jumper" it, that is I took the switch apart, and directly connected the two wires, as to have an always on position, as the switch is messed up..is this ok?
Replaced the coil
Replaced the "electronic" stuff under the coil
Replaced the ECU
Replaced the wires/magnet inside the CAS
I'm out of ideas. What else should I check? I get 12v from the black/yellow wire leading up to the leading coil, and get no voltage in the green/yellow wire. Grounds are good.
Also, the clutch switch (under dash, the switch that will close/open when clutch is pressed), I had to "jumper" it, that is I took the switch apart, and directly connected the two wires, as to have an always on position, as the switch is messed up..is this ok?
12-27-03, 10:08 AM
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OK, I'm about to check the wiring harness today. Since the car has been rigged alot, I'm guessing that somehow a wire got snapped by accident. Also checking the grounds on the harness.. how hard is it to remove it?
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12-27-03, 05:17 PM
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Ok, update.
Volt meter findings:
On the leading coil:
Boost Sensor:
The RPM needle jumps when I try to crank.
Trailing coil sparks fine, leading coil still won't spark.
The thing that bothers me is this. When I got the car, the red wire leading up to the CAS was rigged to a 12v line. I looked on the FSM and saw that this wire goes into the CAS, so I took a reading w/ my multimeter and the wire appears to have no voltage. Is it supposed to have any? I put it back to where it goes in the wiring harness..perhaps they knew something I didn't?
Volt meter findings:
On the leading coil:
- 5v on crank on the green/yellow wire
- 12v when key is on ON in the black/yellow cable
Boost Sensor:
- 5v on brown/white wire in ON position
The RPM needle jumps when I try to crank.
Trailing coil sparks fine, leading coil still won't spark.
The thing that bothers me is this. When I got the car, the red wire leading up to the CAS was rigged to a 12v line. I looked on the FSM and saw that this wire goes into the CAS, so I took a reading w/ my multimeter and the wire appears to have no voltage. Is it supposed to have any? I put it back to where it goes in the wiring harness..perhaps they knew something I didn't?
12-27-03, 05:36 PM
#11
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N0. None of the wires should have 12v tapped into them. There are two coils(windings) in the CAS. You should be able to go to the ECU, remove the largest plug, then read continuity b/t the pin N TO P and T to Q.
None of those pins EVER gets 12v on them. When idling those pins get less than one volt showing on them.
I'm not sure what it would do if someone put 12v on those wires. As in what it would do to the ECU.
Here's some gobbly gook about the ignition system. From what you said about the RED wire......I'd say that was the NE signal. Since you have spark on the Trail maybe nothing really bad has happened. http://www.teamfc3s.org/info/articles/demystifying.html
Your talk about messing inside the cas........may be your problem. Get another cas used for ten to twenty five bucks and try it.
If your using a timing light to see if the Lead is firing...maybe try another method. Try putting BOTH lead plugs close to the strut tower bolts, then take the cas out and spin its gear with your fingers and look for spark at the plugs.
Make sure the Lead Coil is firmly bolted to the frame. The ignitor/coil uses the body of the unit for a ground. Won't fire if say it were sitting on a pile of rags etc. Gotta be bolted down. Just one bolt would do the job. If it's bolted down, then it's ok and don't go off on a tangent and ground everything in site..
None of those pins EVER gets 12v on them. When idling those pins get less than one volt showing on them.
I'm not sure what it would do if someone put 12v on those wires. As in what it would do to the ECU.
Here's some gobbly gook about the ignition system. From what you said about the RED wire......I'd say that was the NE signal. Since you have spark on the Trail maybe nothing really bad has happened. http://www.teamfc3s.org/info/articles/demystifying.html
Your talk about messing inside the cas........may be your problem. Get another cas used for ten to twenty five bucks and try it.
If your using a timing light to see if the Lead is firing...maybe try another method. Try putting BOTH lead plugs close to the strut tower bolts, then take the cas out and spin its gear with your fingers and look for spark at the plugs.
Make sure the Lead Coil is firmly bolted to the frame. The ignitor/coil uses the body of the unit for a ground. Won't fire if say it were sitting on a pile of rags etc. Gotta be bolted down. Just one bolt would do the job. If it's bolted down, then it's ok and don't go off on a tangent and ground everything in site..
Last edited by HAILERS; 12-27-03 at 05:49 PM.
12-27-03, 05:44 PM
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Ok, so I'll leave the red wire going to the CAS alone. I have another ECU, so I replaced that one, so it should still be fine. How do I read the pins on the ECU? Is it in alphabetical order? Thanks.
12-27-03, 06:02 PM
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With the plug connected up, and looking from the wire side towards the ECU...........A is top right. B is just below it. C is the second pin over from A on the top. C is just below B and on and on and on and on from right to the left til you reach the last row on the far left.
When reading the continuity of the coils/windings in the cas, disconnect the plug from the ECU and then read b/t pin N to P and T to Q. You should see approx 110 to 210 ohms on each winding i.e. N-P and T-Q
Is it possible that the timing is off since you have remove and replaced the cas at least once???
When reading the continuity of the coils/windings in the cas, disconnect the plug from the ECU and then read b/t pin N to P and T to Q. You should see approx 110 to 210 ohms on each winding i.e. N-P and T-Q
Is it possible that the timing is off since you have remove and replaced the cas at least once???
12-28-03, 03:53 PM
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Interesting discussion since I'm having a similar problem. I have an '87. Engine was removed for rebuild and is now back in the car. No spark on either leading or trailing as detected by either an inductive timing light or by observing the plugs directly. The simple coil/continuity tests, etc in the FSM all are OK. Since this is coincidental with major service, it's likely something is not connected, or not connected correctly, but what?
I am getting signals to the coils/igniters as measured by a voltmeter or high impedance test light, but have no way of knowing if those are correct. I tried to read out codes from the computer, but it doesn't seem to spit anything out. (Assuming, of course, that I'm doing it right: Short connections on 2-pin test connector, ignition on, monitor outputs on 6 pin test connector with resistor to 12V)
What should I check next? Is there any procedure posted anywhere for troubleshooting the ignition control? That doesn't seem to exist in the FSM. If the CAS is in wrong, would that result in no spark, or just mis-timed spark?
Thanks!
Greg Landry
I am getting signals to the coils/igniters as measured by a voltmeter or high impedance test light, but have no way of knowing if those are correct. I tried to read out codes from the computer, but it doesn't seem to spit anything out. (Assuming, of course, that I'm doing it right: Short connections on 2-pin test connector, ignition on, monitor outputs on 6 pin test connector with resistor to 12V)
What should I check next? Is there any procedure posted anywhere for troubleshooting the ignition control? That doesn't seem to exist in the FSM. If the CAS is in wrong, would that result in no spark, or just mis-timed spark?
Thanks!
Greg Landry
12-28-03, 05:48 PM
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NO SPARK:
1. Check the ENGINE FUSE.
2. Check the 40a EGI INJ fuse.
3. Never use one of those bug lights...ever.
4.Use a digital meter to see if 12v is on the Black/Yellow wire at the two socket connector on the LEAD coil assy.
5. Ohm out the pins at the ECU that come from the CAS.
6. See if there is 5v approx at the brown/white wire at the pressure sensor (convienient place to look is the only reason to look there). No 5v equals busted ECU.
7. Download the fsm schematics and take a hammer to anything that looks like a bug light.
8. Don't have a meter? Don't wanna buy one? Then pay someone to fix the car.
1. Check the ENGINE FUSE.
2. Check the 40a EGI INJ fuse.
3. Never use one of those bug lights...ever.
4.Use a digital meter to see if 12v is on the Black/Yellow wire at the two socket connector on the LEAD coil assy.
5. Ohm out the pins at the ECU that come from the CAS.
6. See if there is 5v approx at the brown/white wire at the pressure sensor (convienient place to look is the only reason to look there). No 5v equals busted ECU.
7. Download the fsm schematics and take a hammer to anything that looks like a bug light.
8. Don't have a meter? Don't wanna buy one? Then pay someone to fix the car.
Last edited by HAILERS; 12-28-03 at 06:05 PM.
12-29-03, 12:11 PM
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Ok, I think I may have found it.
Ohming out the pins in the plug, I get approxametly 50ohms on pins Q and T. I get NO ohms between P and N. So what does that tell me? Something's disconnected..or somethings bad? I'll check on the FSM see if I find anything.
Ohming out the pins in the plug, I get approxametly 50ohms on pins Q and T. I get NO ohms between P and N. So what does that tell me? Something's disconnected..or somethings bad? I'll check on the FSM see if I find anything.
12-29-03, 06:16 PM
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Well, just disconnect the plug from the CAS. Then ring out the wires from one end to the other. As in: the GREEN WIRE to pin N on the ECU plug. The BLUE WIRE to pin P on the ECU plug. And the other two wires the same way. If they ring from end to end......replace the ???????? Yes.
12-29-03, 07:35 PM
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Originally posted by HAILERS
Well, just disconnect the plug from the CAS. Then ring out the wires from one end to the other. As in: the GREEN WIRE to pin N on the ECU plug. The BLUE WIRE to pin P on the ECU plug. And the other two wires the same way. If they ring from end to end......replace the ???????? Yes.
Well, just disconnect the plug from the CAS. Then ring out the wires from one end to the other. As in: the GREEN WIRE to pin N on the ECU plug. The BLUE WIRE to pin P on the ECU plug. And the other two wires the same way. If they ring from end to end......replace the ???????? Yes.
Ok please forgive my ignorance... how do I go about ringing out the wires? Thanks
12-30-03, 10:33 AM
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Sorry 'bout that. Ring out the wires just means putting one meter lead on one end of the wire in question and the other lead on the other end of the wire in question. Then put the meter on OHMS and it should read .000 or maybe .003 or close to that. You do that to make sure that the wire is not broken in between ends. Do that to all four wires that run from the cas to the ECU PLUG.
Most likely they will ohm out and it's the cas that has the fault.....but you never know until you do it.
By the way.....the colors I mention in the above post...do they compare with the pins/wires you have been looking at??????? I say that because you confused me with your picture. The lettering is right but you are looking at where the wires go into the plug, right???? Should be. Check the wire colors.
Most likely they will ohm out and it's the cas that has the fault.....but you never know until you do it.
By the way.....the colors I mention in the above post...do they compare with the pins/wires you have been looking at??????? I say that because you confused me with your picture. The lettering is right but you are looking at where the wires go into the plug, right???? Should be. Check the wire colors.