HEI Distributor question
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
Interesting thread StuK. I've been fighting the same problem as you and doing the same work you have for the same reasons. I'm going to go downstairs and quadruple check my ignition wire placement just in case I have them all one terminal off like you did.
Le Mans Master
Joined: Nov 2009
Posts: 6,882
Likes: 234
From: Bangkok, Thailand
Thanks! I went and checked it and the firing order was correct as was the placement of the wires. I did notice a large ammount of carbon in the center cavity of the rotor, so I cleaned all that out and changed the bushing making sure to re-grease the rubber seal well. It's idling now and I'm going to take it for a test run to see what happens.
Instructor
Joined: May 2011
Posts: 213
Likes: 0
From: Miramar Florida
The BATT connector is the one with the pink (not red) wire. It should have 12 volts on it when the key is on.
IIRC = If I Recall Correctly.
The four wire cable goes to/from the ECM and controls the spark advance. You can bypass the ECM connection by disconnecting the EST bypass connector. It is a single wire connector with a tan wire with black stripe, located next to the brake booster (below the windshield wiper motor). With this connector open the ECM spark advance is not present and your spark advance will be whatever the mechanical position of the distributor is set to. It should be 6 degrees of advance. The key item here is that the ECM is out of the equation with this connector open.
IIRC = If I Recall Correctly.
The four wire cable goes to/from the ECM and controls the spark advance. You can bypass the ECM connection by disconnecting the EST bypass connector. It is a single wire connector with a tan wire with black stripe, located next to the brake booster (below the windshield wiper motor). With this connector open the ECM spark advance is not present and your spark advance will be whatever the mechanical position of the distributor is set to. It should be 6 degrees of advance. The key item here is that the ECM is out of the equation with this connector open.
Drifting
Joined: Feb 2013
Posts: 1,460
Likes: 48
Okay being we are doing C4 ignitions. I just bought a very used C4. I tried to start the car. At least one of the TBI is getting fuel. I took the supple line off. To check. But now I lost my spark. Timing light did not light and I took the plug out held it in my hand and cranked the engine nothing. I made sure that the pink wire was in the cap. Any ideas. Keep in mind minutes before I did have spark.
Oh and I am new to this forum so if I broke any etiquet rules please tell me and I willnot break them again. Thank you
Oh and I am new to this forum so if I broke any etiquet rules please tell me and I willnot break them again. Thank you
Instructor
Joined: May 2011
Posts: 213
Likes: 0
From: Miramar Florida
Okay being we are doing C4 ignitions. I just bought a very used C4. I tried to start the car. At least one of the TBI is getting fuel. I took the supple line off. To check. But now I lost my spark. Timing light did not light and I took the plug out held it in my hand and cranked the engine nothing. I made sure that the pink wire was in the cap. Any ideas. Keep in mind minutes before I did have spark.
Oh and I am new to this forum so if I broke any etiquet rules please tell me and I willnot break them again. Thank you
Oh and I am new to this forum so if I broke any etiquet rules please tell me and I willnot break them again. Thank you
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The forum moderators can lock a thread so that no one can post additional replies. Sometimes you will see "IBTL" on old revived threads, which means "In Before The Lock".
Don't worry about it.
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Drifting
Joined: Feb 2013
Posts: 1,460
Likes: 48
Thank you Bredd1
I brought the ICM to Advanced Auto. The tester said it is okay but a guy behind the counter has a spare ICM for me to try. So by the weekend I will have tested it with new ICM. Does the ICM have anything to do with the fuel pump? Getting NO fuel.
I brought the ICM to Advanced Auto. The tester said it is okay but a guy behind the counter has a spare ICM for me to try. So by the weekend I will have tested it with new ICM. Does the ICM have anything to do with the fuel pump? Getting NO fuel.
Instructor
Joined: May 2011
Posts: 213
Likes: 0
From: Miramar Florida
I don't think the ICM directly has to do with the fuel pump. If I remember correctly, the fuel pump is tied to the distributor tach output to the ECM. Look back into the earlier posts of this thread, it may mention it or it may have been in another post. The ECM looks for revolutions of the distributor then turns on the fuel pump relay. Can anyone else verify this, I'm trying to recall from memory.
Drifting
Joined: Feb 2013
Posts: 1,460
Likes: 48
Interesting my distributor has two tach wires one goes to a condensor on the manifold the other goes to a female connector with no male. The person that sold me the car said it is in its as parked condition so that means that the other tach wire has no home,?
If I am getting no spark but I do have power going into the distributor. Can I assume it is the ICM?
Thank you
If I am getting no spark but I do have power going into the distributor. Can I assume it is the ICM?
Thank you
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I don't think the ICM directly has to do with the fuel pump. If I remember correctly, the fuel pump is tied to the distributor tach output to the ECM. Look back into the earlier posts of this thread, it may mention it or it may have been in another post. The ECM looks for revolutions of the distributor then turns on the fuel pump relay. Can anyone else verify this, I'm trying to recall from memory.
The tach output from the distributor goes directly to the dash cluster and does not connect to the ECM.
One thing to watch for with ICMs is that they can fail when they get hot. Most auto parts stores will test it once and say it's good. The best way is to test it 4 or 5 times to make sure it keeps working. It gets hot pretty fast, so this is a good test.
ICMs can stop working if they don't have THERMAL (NOT dielectric) grease under them. They get REALLY HOT when the engine is running.
Instructor
Joined: May 2011
Posts: 213
Likes: 0
From: Miramar Florida
The ECM uses the DRPs (Distributor Reference Pulses) to tell when the engine is rotating (cranking or running). DRPs come from the ignition module and go through the 4 wire connector behind the distributor to the ECM. When the ECM sees DRPs it turns on the fuel pump. This is done so that the fuel pump doesn't run continuously if you turn on the ignition but don't start the engine.
The tach output from the distributor goes directly to the dash cluster and does not connect to the ECM.
One thing to watch for with ICMs is that they can fail when they get hot. Most auto parts stores will test it once and say it's good. The best way is to test it 4 or 5 times to make sure it keeps working. It gets hot pretty fast, so this is a good test.
ICMs can stop working if they don't have THERMAL (NOT dielectric) grease under them. They get REALLY HOT when the engine is running.
The tach output from the distributor goes directly to the dash cluster and does not connect to the ECM.
One thing to watch for with ICMs is that they can fail when they get hot. Most auto parts stores will test it once and say it's good. The best way is to test it 4 or 5 times to make sure it keeps working. It gets hot pretty fast, so this is a good test.
ICMs can stop working if they don't have THERMAL (NOT dielectric) grease under them. They get REALLY HOT when the engine is running.
Drifting
Joined: Feb 2013
Posts: 1,460
Likes: 48
I am ordering an ICM. But my basic understanding is this. The pink wire supplies 12 volts to the distributor. The voltage enters the distibutor and the ICM acts like points and sends out the pulses. So if I have 12 volts going in and NOTHING coming out of my distributor. The only possible culprit is the ICM. Correct?
Instructor
Joined: May 2011
Posts: 213
Likes: 0
From: Miramar Florida
I am ordering an ICM. But my basic understanding is this. The pink wire supplies 12 volts to the distributor. The voltage enters the distibutor and the ICM acts like points and sends out the pulses. So if I have 12 volts going in and NOTHING coming out of my distributor. The only possible culprit is the ICM. Correct?
Cliff or other member verify if I'm incorrect. Thanks!
