Imperial problems. Stumped.

[Mr C]

Car- 1974 Imperial LeBaron- All stock 440 TQ, factory Electronic ignition.

Issue- Broke down on road trip in vicinity of Butte Montana in July- Temp was 106 that day.

The car just died as I was cruising at 65 mph up to this point on the trip it was flawless and I was getting excellent mileage from 16-18 mpg highway. When I tried to start it, it behaved like it was badly flooded...I initially thought I fell victim to vapour lock... the engine would turn over but not fire. When I sprayed ether down the carb, it would try to catch but falter. I swapped out ECUs, no change.

I had the car shipped home and I put a new coil, cap, rotor, plugs on it. I am embarrassed to say that I left it far too long between tune ups and the cap and rotor were quite worn. I had to put a new terminal on the negative coil connection because the original one was badly frayed and had to be replaced.

Current situation- Cold start- fires right up and runs great. Once it's hot and you shut the car off, it will not start- no spark and the coil feels hotter to the touch than it should.

Looking for advice on where to take it from here.

 

[The Horvaths]

I have been having the same problems with my '67. Your ignition module may be failing when it gets hot. Hope it's an easy fix for ya.

 

[barnfind]

Hows the ballast resistor test? x2 on the ECU

 

[Big_John]

I think it might be the distributor pickup.

Check the gap with a brass feeler first. Disconnect the distributor wire and check resistance between the two wires to the distributor. That should be 800-1500 ohms with 800 being nominal IIRC. That checks the pickup coil. Next check the AC voltage between the two wires (still disconnected). Turn the engine over and you should have >1 volt. Note I said AC.

Less than 1 volt, replace the reluctor. Rare, but it happens. If the resistance is wrong, change the pickup.

 

[Polara_500]

I'm with John, similar issues on my truck in the past that I battled on and off for quite a while. New pickup fixed the issue.
Mike

 

[65Fury440]

I'll take a WAG at it.
What brand of replacement ECU and coil did you use?
Do the pickup test. I would bet it's going to be coil/ECU or pickup.

 

[Mr C]

I'll take a WAG at it.
What brand of replacement ECU and coil did you use?
Do the pickup test. I would bet it's going to be coil/ECU or pickup.

ECU was Mopar
Coil was Borg Warner

I should have mentioned the Ballast resistor checks out.

 

[1978 NYB]

ECU was Mopar
Coil was Borg Warner

I should have mentioned the Ballast resistor checks out.

I bet it's the coil. Once in a while a new one will fail. Is it mounted on the intake? I had the same symptoms with my NYB.........it was the coil.

 

[Mr C]

Yup it's on the intake. It would tick me off if it's the new coil...

 

[1978 NYB]

Mine is on the intake too. It ran a little bit than the engine just quit. It was a brand new Mallory coil. I let it cool off and it would start and run a few minutes and quit again. I put the 37 year old coil back on and it is still running.

 

[commando1]

The good old Standard brand coil that they have churned a gazillion of over the years STILL has never failed on me.

 

[barnfind]

testing coils

 

[Mr C]

Turned out the pickup in the distributor was bad. Thanks to all who helped out.

 

[patrick66]

I had that very thing happen on a 1989 Dodge D150 I had years ago...and it was the pickup coil that quit. I found a r/b distributor for just a few bucks more than a new pickup coil and swapped. Worked great.

 

[Funship32]

That's funny. I was just going to tell you that I had a similar problem with an '85 chrysler and it was the pickup in the distributor. Guess I should get here earlier next time. ;-)