1995 coil packs and Mod

My sisters buick has the 3800 in it. This will be the 3rd time changing the coil packs and mod (part under the packs). I have changed them 3 times and now it has happened again. The car will start fine and run fine until she turns it off. Then she can't start it again until it cools for about an hour. After changing the the packs and mod. this will stop happening for awhile. But only like a month or so. Then it starts again.

I told her that this time she had to take it to the dealer to find out why. Because these things are not cheap. They charged her $90 to check it out and told her she needed new packs and mod for it. I then went there myself and asked them what would make these go bad so fast. They said they would have to change them first then test some other things.

This is starting to cost to much. They want $470 to change them and then start looking for other things? I don't think so........ :banghead:

So now I'm here to pick your brain. Has this ever happen to anyone here? What was the problem? How can I fix it?

Anything will help .,....

I need some ideas on where to start... I have never had this happen before...

PLEASE???

No spark? I assume, some parts houses warranty these for up to a year. If no start do you show cranking rpms on a scanner, the crank sensor can have similar symptoms, so can a bad connection at the module connector.

My sisters buick has the 3800 in it. This will be the 3rd time changing the coil packs and mod (part under the packs). I have changed them 3 times and now it has happened again. The car will start fine and run fine until she turns it off. Then she can't start it again until it cools for about an hour. After changing the the packs and mod. this will stop happening for awhile. But only like a month or so. Then it starts again.

I told her that this time she had to take it to the dealer to find out why. Because these things are not cheap. They charged her $90 to check it out and told her she needed new packs and mod for it. I then went there myself and asked them what would make these go bad so fast. They said they would have to change them first then test some other things.

This is starting to cost to much. They want $470 to change them and then start looking for other things? I don't think so........ :banghead:

So now I'm here to pick your brain. Has this ever happen to anyone here? What was the problem? How can I fix it?

Interesting that the coil packs and ignition module all go...I wouldn't think that all coils and modules were borderline when new and getting ready for failure. Of course, getting a batch of "bad" parts is not the strangest thing in the world. That's one possibility especially if it's aftermarket, but this doesn't seem likely. I like OEM parts epecially for the ignition system.

As max has said, the crank sensor can show the same symptons along with an intermittent connection. Do you know how the coils and module failed? How did you check them to confirm these parts failed.

Another possibility is that replacing these components may have temporarily made a connection somewhere "fixing" the problem making the other components seemed "bad".

Once I got the vehicle running, I would throw a scope on the ignition system especially the primary circuit using a current probe. At least at this point, bad components bought new can be seen if the coil(s) are drawing too much current which is taking the module out. I'm not sure how the coils failed (maybe shorted winding) along with the ignition module, but if this is the case, it sounds like the coils are drawing too much current if all of the components failed. I'm not sure about this vehicle, but I believe that the ignition module should limit the current to the coil once it has become saturated. I believe a signal from the PCM to the ignition module determines the time for this to happen.

First thing I would do is a thorough visual check of your connections especially around the primary circuit and around the ignition module.

Anyway, I hope you get it going! It sounds like an interesting problem...

I'm not pos. that the coils are bad. With the mod going out it make it seem like they are. I have replaced these with bone yard parts only (nothing new) so when you buy these from a bone yard they sell you everything as a unit. Then I just replaced everything. So I'm not really sure that the coils are bad.

I think I will fix them one more time, then take it to the dealer and have them find the other problem.

Thanks for all the info......