Ignition Coil Wiring

[forzaphil]

I hope everyone is not tired of my posts... I really appreciate the help, and I feel like I am really close!!

I'm trying to diagnose rough running conditions and think that somewhere down the line, wires on the ignition coil got switched around. The problem is i am not sure which ones. Artigues wiring diagrams show this as correct:
Pink wire from ignition switch and red wire from ignition module to +b terminal on Coil. Brown w/white stripe to ECU and black wire from ignition module to d terminal on Coil.
but this is what I have:

How do I know which of the little posts on the coil is positive (B+) and negative (D)? I tried reading secondary resistance, but I get 8500 ohms between the main spark output (going to the dizzy) and EITHER of the little posts. Does it matter which of the little posts on the coil I hook pink and red to?
And for completeness, between the B+ and D little posts on the coil I show resistance of 1.7 ohms.

I know pink is supposed to be with red but I am not sure if the pink wire got switched or the red wire got switched. I AM GOING TO BEAT THIS PROBLEM! I SWEAR IT! (Thanks all for your help, time, and patience )

[So Cal Mark]

the coil should be marked with a + next to the positive post. The coil will work either way, but if you hook it up backwards the maximum spark will be reduced by about 50%

[grittracing]

if it is running rough look for vacume leaks. I just found one on my car. almost night and day differnce. also your injectors could be pluged.

[forzaphil]

Okay, after doing some more investigating, I think it was hooked up properly in the first place. The PO had the black and red wires reversed on the ignition module so they had them switched on the coil leads too.

I am investigating possible weak spark from the Coil. Is it possible that when my magnetic pickup wire melted on my exhaust heat shield (i have since replaced it and gapped it correctly) that it somehow fried the coil or the ignition module, and still makes spark but not very strong spark?

How critical are the ranges for ignition coil resistances? It seems like when coils fail they just go kaput and stop making spark altogether. I am wondering if the coil resistance has been low all along and is unrelated to my problem or if it was reduced when all my troubles started in the first place.

Primary Resistance: 1.7 ohms.
Secondary Resistance: 8500 Ohms.

Are those acceptable or can those be causing weak spark?

[majicwrench]

If you are worried bout weak spark is easy to test. Get a spark plug, open the gap WAY UP, .090 or so. Hook it in a plug wire and see if it will jump gap.
Or get a buddy to hold onto the coil wire while you crank engine. He should jump at least 2ft in air. Anything less is weak spark. WARNING: Do not use your wife for this test.
Usually if you have weak spark car will be hard to start and will miss under heavy load. Not sure just what "rough" is in your case.
Keith

[grittracing]

mine doesnt want to run when its cold or sometimes when i come to a fast stop. ( i have turn the idle up to 1500 rpms and even once to 2000 rpms FI motor any ideaS

[chrisfiat]

check the entire intake system for vaccume leaks. especaily the intake boot throtle housing and air tubes. this is not a spark issue

[forzaphil]

Keith, don't worry, the thought of hooking my wife up to my ignition coil never crossed my mind. She has beautiful curly hair and I don't think it standing on end would be a good look for her. A few buddies might deserve that though .
Mark, you were right, there was a big fat + sign on positive. just covered in a bunch of grime. Oops a daisy...

And as far as Vacuum leaks, I am not sure if that is the problem. I have checked somewhat, but I will do a real thorough check to be sure.

The symptoms are: Clean plugs allows the engine to run smooth for a while till I rev it up, then it starts backfiring and not all cylinders are contributing. I pull the Plugs and they have black sooty carbon build up. It seems like the system is delivering too much fuel without enough air. Air cleaner clean, and spark seems strong. When I was diagnosing the Aux air reg. I disconnected the hose that goes from the Big Air intake hose to the AAR and the engine seemed to level out like it was able to suck enough air finally. I have reason to suspect the coolant temp sensor, and one should be here tomorrow morning. I also want to check the resistance of the wires from the temp sensor to the ECU to check for breaks or bad connections. Thank you so much to everyone for your support! Without this forum and the encouragement I would have broken down long ago. Next Payday I am gonna donate to the forum. Keep it up and running!

[forzaphil]

Hello everyone, I'm back with my report.

I changed out the Coolant temperature sensor and in so doing, I realized it was low on coolant. After a few attempts of trying to jack it up and burp it and let it run through the fan cycles etc etc. to get the air out I thought "This is ridiculous" and went to autozone, spent $3 on hose clamps and a Flushing tee with a cap, (5/8 inch by the way) installed it on the heater hose going into the block and it didn't take more than 4 minutes to have the system free of air.

After coolant is good, I get it running at idle and it sounds beautiful. It ran that way for quite a while, until I of course I try to rev it up. Then the idle slows down because not all cylinders are firing anymore and it's misfiring. FRUSTRATING! Here is a video of the process.

http://www.youtube.com/watch?v=EG0GnmGYD_c

Here is what I know.

1. I don't lose spark when it is sputtering and misfiring. I put a timing light on each wire after it has started doing it and each is sparking fine. I think the plug itself might be fouling up causing it to not spark, but the spark is going through the wires themselves.
2. Airflow meter resistances are fine and the flap moves freely.
3. Aux Air regulator opens with a cold engine and slowly closes till it shuts completely.
4. New coolant temp sensor
5. Cold start valve working properly. no drips/not stuck open.
6. Fuel pump works like a champ.

Things I have questions about.
1. I tried sucking on the fuel pressure regulator to see if the diaphragm was broken but no fuel came out (I'm desperate to fix this car ) Is there another way that it could be malfunctioning and putting too much fuel into the plenum?
2. The throttle position sensor clicks as I move the accelerator linkage and as it returns to idle, but is there another way that that could be defective and on acceleration it is telling the ECU to put too much fuel in?

I appreciate everyone's help so very much. This forum is incredible. I think i am really close to solving this...

[forzaphil]

Coil resistances seem off (1.3 ohms primary and 8500 secondary) however I opened up a spark plug gap real wide but the spark still jumped it. It was yellow and barely visible, but it stings like a mother's wooden spoon when it jumps through you. Bad coil perhaps?

[bobplyler]

Bad coil perhaps?

Could be. That's not the OEM one, but a replacement that doesn't fit quite the same. I've got the same thing on my car. It shouldn't be too expensive.

[forzaphil]

The more and more i troubleshoot the more things seem to be working fine. But there are a few things I have questions about.

1. Mechanical advance. The car will idle just fine for as long as I want it to and stays at 11 degrees btdc, but when I start to increase rpms, it starts to choke out. As the RPMs increase, isn't the timing supposed to advance as well? It stays at 11 degrees according to a timing light without advancing with RPMs. How does the mechanical advance go out? Is it something simple like the springs in side the distributor?

This is a video of me moving the distributor around with my hand.
http://youtu.be/4fuxYfQxEpE

and here is another of right after running the engine, revving it up and it bogging down. I pulled off the main air hose and this is what I saw.
http://youtu.be/sxySyjCPP2A
Fuel vapors I assume. Would that happen if the mechanical advance isn't working?

I thought perhaps the vertical play in the distributor was causing the pickup to stop sending spark from the coil, but even at high RPMs the spark is really consistent per the timing light. I looked at it and it is purple/blue spark, so nice and strong. I don't think it is the coil anymore. If anyone has insights let me know. Thanks so much for sticking this one out with me everyone.

PS. The fuel pressure regulator makes a noticeable hissing noise when the fuel pump is running, but the vacuum line does not have traces of fuel in it... Not sure if there is another way it can fail....

[lanciahf]

In your video of disconnecting the coolant switch while the car was idling. I noticed the car continued to idle after unplugging the sensor? Was the car at operating temp? If it was the car should have dies as disconnecting that switch will cause the FI system to go to full rich. Usually the mixture is too rich to allow the motor to continue to idle. Also in another post from April 2011 you mentioned that you moved the PCB board on the AFM? This is another no no, Did you ever replace the AFM? I think you are so far from a stock setting that you are chasing problems compensating for other problems.

FI Guides
http://www.njfiats.org/joomla15/index.p ... &Itemid=70

[rlux4]

You've got some questions here that haven't been answered. Here's a couple I can help with. Your fuel pressure regulator;
It's very easy to check fuel pressure by putting a liquid pressure gauge on the line going up to the cold start valve. I made mine with a gauge and some brass fittings with a barbed nipple at the end that will go into the rubber hose. Also; the throttle position sensor doesn't signal the ECU for the amount of fuel, it only opens the circuit during decelleration to signal "no need for fuel". Hearing the clicking most likely indicates that it is working, but it is easy to check also. Take off the connector, hook an ohmeter to terminals numbered 2 and 18. At closed throttle the circuit should be open, move the throttle and the circuit should close.
Clean the resistor surface under the black cap of the AFM. Isopropal alcohol on a Qtip works well for this. You say the reading of the AFM are good, but if you look closely at the resistor track you may see a couple of spots that appear more worn than the rest of it. These will be at the points where it's at idle and at normal cruise, the positions most used. If you move the sweep arm slightly up or down the shaft it will put the sweep arm on a new path on the track and will help if this is your problem.
Are you sure your ignition timing is on? I had used the wrong notch on my pulley a while back and the timing was way off, it would run but not well, and not idle below 1200 rpm.
Hope this helps.
Ron

[Sunracer]

Couple things to check. 1. yes your timing should advance when you rev the engine and watch the timing light. If it doesn't your advance system is stuck. Remove the springs, pull of the weights and clean everything up inside the distributor. The weights should pivot freely on their posts. 2. Hook up a vacuum hose to your vacuum advance pot on the distributor and suck on it. If you can pull air through it, it is shot and will also be causing a vacuum leak. You can buy a replacement.
Hope it all helps.

If you suspect your coil, the manual should have a spec to test it. If it is original it is probably weak. good aftermarket alternatives are the Pertronics Flamethrower or MSD Blaster2. Many people are using these with good results with the factory electronic system.

Get a hold of the FI trouble shooting manual-should be on line some where, it gives a pec of all the components that you can test with a meter. Anyone around with a good running FI car so you could try swapping the AFM and computer? It is easy to do. Good luck. PB