carrmann

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?

Cliff Harris

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.

carrmann

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.

ghoastrider1

if I remember correctly, the L-98 vette engine uses a smaller dist. than found on others. The Base likes to hit the intake and not seat firmly on the older HEIs.

Raidmagic

The one you bought from the parts store was for non computerized cars. That is what the vacumm advance was for. You were right to return it and it appears that you found your issue.

carrmann

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.

Cliff Harris

Sounds like a problem with the fuel pump relay. Does the fuel pump run for 2 seconds when the ignition is turned on without starting the engine?

Raidmagic

Have you removed the dist.? If so make sure you got it back in the proper way. If you are off a bit on the timing that can cause hard starts.

carrmann

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.

Midnight 85

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.

Scottlsullivan

Take the # 1 spark plug out put a damp toilet paper over the spark plug hole bump the ignition switch until you hear it blow the paper off take the distributor out point the rotary button at the last rocker arm on the drivers side if the distributor will not go all the way down take a long screwdriver or lugwrench then stick it down through the intake hole and turn the oil pump shift so it will line up with the distributor then install the distributor then put it back together woohoo