replacement distributor
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 47
Likes: 0
replacement distributor
my 86 corvette keeps losing spark. will turn over but not fire up .
i replaced coil, cap and rotor and it drove good for a few weeks then happened again.stopped on the way to work ,would turn over but not fire , later that day went to try and get it home and problem persisted, then after a few tries it fired up and drove home.
a mechanic suggested to replace the whole distributor.saying it was probably the pick up coil or the control module.
i bought an accell and it came with the big vacuum advance sticking out the side. so i returned it and the parts counter people said it should work.that it was listed for the 86 corvette.
does any one have any suggestions as to what would cause the problem.
and does anyone have a suggested replacement for the distributor.
should i just replace the picup coil and control module in the distributor?
i replaced coil, cap and rotor and it drove good for a few weeks then happened again.stopped on the way to work ,would turn over but not fire , later that day went to try and get it home and problem persisted, then after a few tries it fired up and drove home.
a mechanic suggested to replace the whole distributor.saying it was probably the pick up coil or the control module.
i bought an accell and it came with the big vacuum advance sticking out the side. so i returned it and the parts counter people said it should work.that it was listed for the 86 corvette.
does any one have any suggestions as to what would cause the problem.
and does anyone have a suggested replacement for the distributor.
should i just replace the picup coil and control module in the distributor?
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You can have the ignition module tested. I know that AutoZone can do it.
The ignition module gets VERY hot when the engine is running. There is a thermal fail-safe circuit in it the will shut off the spark if it gets too hot. The module should have THERMAL grease under it. Sometimes people put dielectric grease under it, which doesn't work.
The pickup coils seldom fail. You can measure the resistance to see if it is OK. Mine measured 800 ohms, but the FSM shows a huge tolerance on that reading: 500 to 1500 ohms. You have to take the distributor out and take out the shaft to replace the pickup coil. I have heard of pickup coils crumbling into pieces, but I believe that was a problem with earlier units back in the '70s and no longer applies to C4s.
The HEI distributor works quite well and any replacement would not be an improvement unless the engine is radically modified.
The ignition module gets VERY hot when the engine is running. There is a thermal fail-safe circuit in it the will shut off the spark if it gets too hot. The module should have THERMAL grease under it. Sometimes people put dielectric grease under it, which doesn't work.
The pickup coils seldom fail. You can measure the resistance to see if it is OK. Mine measured 800 ohms, but the FSM shows a huge tolerance on that reading: 500 to 1500 ohms. You have to take the distributor out and take out the shaft to replace the pickup coil. I have heard of pickup coils crumbling into pieces, but I believe that was a problem with earlier units back in the '70s and no longer applies to C4s.
The HEI distributor works quite well and any replacement would not be an improvement unless the engine is radically modified.
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 47
Likes: 0
i replaced the pick up coil and the ignition module. the pick up coil magnet was broken into three pieces.
i test drove it for about fifteen minutes and it seemed to run fine.
I hope this takes care of the problem , only time will tell.
i test drove it for about fifteen minutes and it seemed to run fine.
I hope this takes care of the problem , only time will tell.
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 47
Likes: 0
The car runs fine now , but doesn,t start so easily.
When i turn over the engine it stumbles and the motor shakes hard side to side.
on about the third try it fires up .and when driven it runs normal.
is this possibly from installing the parts not perfect.
i had help from a mechanic rebuilding the distributor, but it started fine before i rebuilt the distributor.
When i turn over the engine it stumbles and the motor shakes hard side to side.
on about the third try it fires up .and when driven it runs normal.
is this possibly from installing the parts not perfect.
i had help from a mechanic rebuilding the distributor, but it started fine before i rebuilt the distributor.
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Thread Starter
Intermediate
Joined: Dec 2013
Posts: 47
Likes: 0
yes ,the distributor was removed to replace the pickup coil and control module.
when i removed the distributor i took pictures so i could put it back in exactly as removed. my mechanic said it would be better to pull up #1 piston and then line up the timing mark an ithen install the distributor with the rotor pointing at #1 position.
the distributor now visibly off from where i pulled it out.
the wire plug in on the cap was pointing directly towards the drivers side fender , and now it points more towards the drivers seat/ steering wheel to make it run.
im sure something is not right.
im sure we did something wrong reinstalling the distributor that is causing this.
he said the oil pump was making this not line up correctly.
can you recommend a way for me to start over , to correct this.
if i just loosen the hold down and move the distributor back to the original direction , it will not start or orun.
when i removed the distributor i took pictures so i could put it back in exactly as removed. my mechanic said it would be better to pull up #1 piston and then line up the timing mark an ithen install the distributor with the rotor pointing at #1 position.
the distributor now visibly off from where i pulled it out.
the wire plug in on the cap was pointing directly towards the drivers side fender , and now it points more towards the drivers seat/ steering wheel to make it run.
im sure something is not right.
im sure we did something wrong reinstalling the distributor that is causing this.
he said the oil pump was making this not line up correctly.
can you recommend a way for me to start over , to correct this.
if i just loosen the hold down and move the distributor back to the original direction , it will not start or orun.
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
I can only guess that your mechanic put the distributor back in correctly, he is correct about how to do it but may not have got it right. Turn the engine over until the timing marks line up as close to exact as you can, use a breaker bar & socket to move it the last little bit so you can line up the marks. Once the marks are lined up, pull the dist. cap, the rotor should be pointing directly at either the number one or the number six terminal in the cap. If it is pointing anywhere other than the 1 or 6 terminal you will have to pull the distributor up far enough to move the rotor to align with the terminal. Remember you will have to allow for movement of the rotor as the dist. drops back into position. Just remember to only move the rotor to whatever terminal it is closest to, 1 or 6. If when you get the cap off it is pointing directly at either terminal I mentioned, do no more because it is set correctly and there is another problem.
7th Gear
Joined: Mar 2014
Posts: 7
Likes: 0
Distributor
yes ,the distributor was removed to replace the pickup coil and control module.
when i removed the distributor i took pictures so i could put it back in exactly as removed. my mechanic said it would be better to pull up #1 piston and then line up the timing mark an ithen install the distributor with the rotor pointing at #1 position.
the distributor now visibly off from where i pulled it out.
the wire plug in on the cap was pointing directly towards the drivers side fender , and now it points more towards the drivers seat/ steering wheel to make it run.
im sure something is not right.
im sure we did something wrong reinstalling the distributor that is causing this.
he said the oil pump was making this not line up correctly.
can you recommend a way for me to start over , to correct this.
if i just loosen the hold down and move the distributor back to the original direction , it will not start or orun.
when i removed the distributor i took pictures so i could put it back in exactly as removed. my mechanic said it would be better to pull up #1 piston and then line up the timing mark an ithen install the distributor with the rotor pointing at #1 position.
the distributor now visibly off from where i pulled it out.
the wire plug in on the cap was pointing directly towards the drivers side fender , and now it points more towards the drivers seat/ steering wheel to make it run.
im sure something is not right.
im sure we did something wrong reinstalling the distributor that is causing this.
he said the oil pump was making this not line up correctly.
can you recommend a way for me to start over , to correct this.
if i just loosen the hold down and move the distributor back to the original direction , it will not start or orun.