1987 model 328 GTS / sudden power loss / stall

Sounds like you lost one bank of cylinders, if that's the case, don't drive it until it is resolved. It can cause a fire.

 

You should also check your spark plug extenders for any pinhole sized burn marks. I had similar symptoms and found one of my plug extenders had a burn mark. I replaced it and all was back to normal.

 

You lost a bank for sure. Check connections around both coils. It is ignition,100%

Do not start messing around with the fuel system. It is not the problem

 

Doesn't sound like your plug extenders since they usually fail one at a time and almost never cause the car to stall; just run rough at idle/low speed. Most likely one of your two coils....just need to determine which one it is since the coil modules are about $700 each. Unless the coil has failed completely, in which case it will be easy to determine which bank is not firing the only way to diagnose is to drive it until you lose one bank then immediately get into the engine compartment and find out which bank is not firing.

 

Since it is an electrical issue it will continue to be intermittent until it fails completely......which could happen at any time or never. That is correct the coil is a generic 80's replacement coil. Once the car dies quickly pull the plugs...you should have unburned fuel in at least 1 of the cylinders. One other way to solve the problem is buy 1 coil and replace 1 of your existing coils and see if that clears the problem....if not you know it is the other bank. Certainly not 100 % it is the coil but that is the most likely culprit.

 

Loose crank position sensor

 

Depends how your idle is set.
I did experience loss of power and stalling at idle from bad plug extenders, but there were a few that weren't 100% as well as the one gone completely.

But bad coil or bad plug extenders don't tend to come back.
A loose coil wire might, or possibly a foreign object in one of the distributors or a failing distributor rotor.

There's a slight chance could possibly be the O2 sensor protection relay in the rear deck area.

Intermittent problems can be tricky to find. Few problems in a car "go away" by themselves.

 

Something very similar happen to me many years ago on my '87 GTS. A member of this forum suggested I check the wires from the coils to the distributor. As there was plenty of length of the wires, I removed each from the distributor, cut about 1/2 inch off and reset them. The problem immediately went away and never returned. This might be your problem too. Problem is electrical, not fuel.

 

If you have a coil on the way out , you might develop a misfire. Drive the car from cold and as soon as you get a problem, get out of the car and feel both coil packs. If one warmer than other then that one on way out. Mine would go about 2 to 3 miles then misfire etc.

 

Afternoon Joe,
My car did the same when I first bought it. Parked to the side of the road and with engine idling, I unplugged and plugged the connectors going to the ignition modules. One at a time of course... suddenly the cylinder bank started working. Has not failed again until today(that was ten years ago).

Hope this helps.

John.

 

Joe,
These coils and modules are used in many Fiats. Superformance U.K. has them.
If it's the module, I have an extra one, you can have it for free.
It's aftermarket, yet works ok, I've swapped it and can't notice the difference.

John.