93 400E bad coil?

[alpineviking]

I have an infrequent miss at idle. It takes a long crank to start it when it’s hot. It starts easily and runs pretty good cold. I have replaced everything in the fuel injection. I have replaced everything in the ignition, with exception of the two coils. I read that these twin coil cars
have a tendency to develop defects in their coils. Both of my coils put out a strong spark at the distributor. This doesn’t mean that they won’t short out when the engine bay is very hot. Anyone had experience with coil failure on these cars? thanks very much

 

[gerryvz]

Have you replaced the caps and rotors, and more importantly, the insulators behind each cap? Also, checked the resistance of the spark plug and coil wires? I'd start by inspecting the caps, rotors and insulators first.

About 10,000 threads covering your exact issue here on the forum !!!

 

[gsxr]

I have an infrequent miss at idle.

How bad of a misfire? An occasional hiccup, or engine-shaking idle only when hot?

It takes a long crank to start it when it’s hot. It starts easily and runs pretty good cold. I have replaced everything in the fuel injection.

If the extended cranking is only when hot, this could be the fuel pressure regulator at the back of the fuel rail. Did you replace this yet?

I have replaced everything in the ignition, with exception of the two coils. I read that these twin coil cars have a tendency to develop defects in their coils. Both of my coils put out a strong spark at the distributor. This doesn’t mean that they won’t short out when the engine bay is very hot. Anyone had experience with coil failure on these cars? thanks very much

Does this mean new caps, rotors, insulators, plug & coil wires, and non-resistor plugs? Coil failures are relatively rare, need more details on what exactly you are experiencing. New Bosch coils aren't expensive but are a minor nuisance to replace as you should pull the headlight out for access.

 

[winmutt]

Ohms on the CPS?

 

[gsxr]

CKP (Crank) or CMP (Camshaft)?