Community Forums

glennj3cub · 01-08-2016, 10:11 PM

There is always something new to take care of

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Driving home my engine started skipping some, backfiring occasionally. The tachometer was not steady.
I have owned my HR for about 2 years so I have no idea how old the plugs, wires and points are. I assume it has points.

Without attempting to do too much (I always screw things up when I start replacing those wires) !

The tachometer is electric so I assume it runs from the coil?

Plan to replace the plugs first, take a look at the distributor cap and points, then see if that took care of the skip. If not will move on replacing everything.

Wondering how much trouble it would be to put in electronic ignition?

Glenn

PJStough · 01-08-2016, 10:18 PM

In my experience, the number one reason for a 454 to miss or backfire, is bad plug wires. I would check those first.

FunGus · 01-08-2016, 10:53 PM

Quote:

Originally Posted by PJStough

In my experience, the number one reason for a 454 to miss or backfire, is bad plug wires. I would check those first.

X2 on the bad wires! And don't replace them with the cheap ones if you don't want to have to replace them again in less than 10k. Get the ceramic tipped wires or they will just burn off with the manifold heat.

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dix39 · 01-08-2016, 11:09 PM

Depending on the year, it may already have electronic ignition. There is also a chance that the tach is intermittently shorting out the ignition. I've never had the tach problem, but my son has several times with aftermarket tachs. Disconnecting the tach would answer that question.

Best of luck, our MH has a 454 too, but we've only had it a few months. It's a '93 and I have factory shop manuals ('94) for it. If I can look anything up for you please let me know.

Steve

leesdx1 · 01-08-2016, 11:32 PM

Quote:

Originally Posted by FunGus

X2 on the bad wires! And don't replace them with the cheap ones if you don't want to have to replace them again in less than 10k. Get the ceramic tipped wires or they will just burn off with the manifold heat.

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X3 on the plug wires, could be bad or loose connection. Either way, your in the right direction on doing the tune-up.

What year is your beast??

POPPASMURF · 01-08-2016, 11:43 PM

I assume you have a doghouse covering your engine. One method to check plug wires is to remove the doghouse and then find a really dark place and start the engine. In the dark you may see halos around the wires- that is a sure fire way to tell if wires are kaput, if you don't have a lot of instruments for diagnostics.

Deano56 · 01-09-2016, 07:22 AM

If you suspect its a wiring problem you can also mist water on them with a spray bottle. A bad set of points or a bad condenser can cause the same symptoms as bad plug wires, backfiring and missing. I'm not sure when electronic ignition came around. Napa sells a good set of wires that won't break the bank and they are lifetime guaranteed. I think they are labeled Beldin, there are bigger and and more expensive ones but I don't think they are needed for a stock engine

spritz · 01-09-2016, 08:42 AM

Not to rain on the parade but why did you wait 2 years to change the plugs wires and points,? at least on mine just looking at them told me they needed a replacement.

My tach we just installed is connected to the distributor it tells you what wire to hook too.
I have a 82 - 454 w/manual's if you need. Hope you get it figured out and tell us what you found.
Good Luck,
Tim

JMonroe · 01-09-2016, 10:43 AM

Yup, agree with the plug wires being the most suspect. Whenever our old Suburban started missing I knew it was past time to change the plug wires.

whem2fish · 01-10-2016, 04:11 AM

he has a 1987 it has electronic ignition the tac wire hooks to the cap on the top where wires go in

swampdog2 · 01-10-2016, 04:25 AM

So I assume you have replaced that fuel filter ???? I had an 87 454 H/R that started missing and back firing took it to a shop and 300.00 later I replaced the fuel filter after the so called mechanic said it needed a valve job 4.00 fuel filter fixed it.

George Schweikle · 01-10-2016, 05:38 AM

Some call it the "Secret" fuel filter due to the location on the frame rail halfway between the gas tank and engine.

On our carburated 1982 Winnebago Chieftain 454, I knew to change the fuel filter when the engine hiccuped if I gave it a little gas at highway speed. Our fuel injected 1999 Safari Trek 454 had an intermittent check engine light that disappeared after changing the fuel filter.

Quote:

Originally Posted by swampdog

So I assume you have replaced that fuel filter ???? I had an 87 454 H/R that started missing and back firing took it to a shop and 300.00 later I replaced the fuel filter after the so called mechanic said it needed a valve job 4.00 fuel filter fixed it.

mohamer · 01-10-2016, 07:24 AM

I enjoy skipping rocks on a pond, 454s are hard to skip, very heavy and sink real fast!!!

TQ60 · 01-10-2016, 08:58 AM

Others hit most.

In the past there was a place that did tune up whatever it takes for 49.95 and if it only needed one plug wire that is what you got.

Given the year assume never tuned up so it needs what is called major tune up.

And do NOT go cheap.

The doghouse holds heat and plug wires are routed where it is hot so pay extra for high temp wires as it is not really that much more and do homework by using Google to confirm quality as the wires are the weakest link and make the most difference.

Cap rotor and any other secondary part.

The coil module in the cap should be fine but if not expensive replace and keep old parts as spare.

Fuel filters all need changed and sometimes on in front of carb if it has one.

Open connector plugs and inspect for condition.

Check and replace vacuum lines to controls.

Remove and clean or replace egr.

Do get a Haynes or Chilton manual as they have great instructions specific to your unit.

Do one plug and wire at a time and read the plugs as they tell you how engine running.

Take an egg carton and draw a fan on one end and wheels at the other then place plugs in holes that match.

When done yiu can see what each cylinder is showing and look for the "different" one.

Post photo for assistance.

Get a vacuum gage and after done put in park and after warm up slowly rev engine to high idle to maybe 2k and observe steady vacuum and listen.

Next set brake and stand on brake and do same in drive but only short time and lesser rpm.

Then road test.

Report back progress and ask questions before doing anything else.