Electrical issue 454 engine

[Brenda E North]

We are fairly new owners of a 1985 TIDWELL motorhome. The engine is a 454 and runs great most of the time. We have been having problems with just stopping running as we are driving down the road. Sometimes it starts back up easily and sometimes it takes a few cranks of the engine. Frequently it backfires when restarting. We have it in to two different places to be worked on. They say they can't identify or duplicate the problem. The light on the dash goes out just before the engine quits and everyone says that indicates an electrical problem. Does anyone have any advice??

[Russell E Johnson]

We had a problem like that last summer. Joe's RV in Jonesboro, AR worked on it on and off for 2 weeks. There were bad fuse connectors and relays associated with the chassis and the cabin. He had 2 men on it and so $100 worth of parts cost us about $500 in labor. It is not going to be easy to find until it finally dies completely like ours did which took about 18 months to get to that point. Not encouraging I know, but it is the best I can tell you. Do not expect a regular mechanic garage to be able to fix it, and I seriously doubt that the majority of RV dealers have the necessary experience to figure it out. I do not know of any independent RV repair places in Washington state. I hope others on here in that area will know of someone they can recommend. Good luck

[Brenda E North]

Thank you Russ. You are right. It is not encouraging but it is better to have some kind of answer.

[Russell E Johnson]

Here is link to a website that I wish all RVers would use. Since it is not used much a lot of reviews are old. But it might give you some guidance. 

RV Service Reviews

[Brenda E North]

Thanks I will check it out.

[Terry H]

Does the engine die only after running for a while - operating temp or higher?

Is it easier to start if you allow it to cool down? A BBC in a class A takes a considerable amount of time to cool down. There are tips, especially when stopping enroute for fuel or coffee that will help your exhaust manifolds.

Does it back fire through the carb or exhaust?

Basic problem as per your post and dependant on above, to me, point towards an ignition coil problem.

[Brenda E North]

Thank you Terry. Didn't mean to seem to ignore you. I am trying to research this for my husband.  It does backfire through the exhaust. I showed him your comment and he went to our only auto parts place in our little town this morning.. The guy apparently has a lot of experience with GM. He agreed it could be ignition related but advised changing the ignition control module instead of the coil since the problem is intermittent.. I really appreciate your advice.  

[Terry H]

Happy to hear this, Brenda+. The ICM replacement will deal with various issues that the coil won't. Appears you have found someone local that knows these older engines. You are very fortunate.

In many cases these days you could end up trying to deal with a 30ish 'associate' who has no knowledge of what a carb is.

Cherish this person you have found.

Apologies for suggesting the coil ahead of the ICM.

Something you may want to consider with an older engine is to avoid 'throwing new parts into it'. Generally not needed. Most parts are testable.

Todays vehicles have so many computer modules that cannot be bench tested and require a specific code reader with the provision that you test with a 'known good component' that you have to have a life time warranty.

Good luck with yours.

1985 454 is a very strong and dependable engine.