Crusader 454 with misfire issue

[Bizsoft]

Hey Guys,

I have 1980 Uniflite 42 DC with twin 454 Crusaders. The port motor has a pretty bad misfire issue. I replaced the cap and rotor, no change. I want to replace the spark plug wires (plugs are also new) but some folks have said that some of the available wires don't work well or are mis-sized. Looking for advice on the manufacturer and where to get the new wires. Thanks in advance for your help. Stay healthy!

- Dave G.

 

[menzies]

I wouldn't listen to "some folks."

My last boat had twin 454 350s and those engines are great. And very popular, especially among 80s and early 90s boats. Before they came out with CaptainsChoice engines.

I replaced my wires around 2004-5 and found them easy to get.

Call one of their network by putting your zip code in here.

https://www.crusaderengines.com/offshore#locator

Or check out these links.

https://www.westmarine.com/buy/sier...VwpcRYv2gGQQvim0r9z82aTvFXTCIbfhoCL3cQAvD_BwE

https://www.marinepartssource.com/c...yWS-DBYCbcQ5ZhZE-M8sosmu6MmDTmXhoCup8QAvD_BwE

https://www.marineengineparts.com/crusader-marine-98171-spark-plug-wire-set

 

[Bizsoft]

Do you remember what brand of wires? Reviews of the Sierra wires are not good. I'm thinking the Delco's might be a better choice.

 

[menzies]

Do you remember what brand of wires? Reviews of the Sierra wires are not good. I'm thinking the Delco's might be a better choice.

I don't, and that boat has moved on.

I updated my post with the Crusader network link - call one of them near you - I think there are three or four near your zip code when I put it in.

 

[Bizsoft]

Thank you Menzies.

 

[Pau Hana]

It’s a basic gas v-8 engine, and treat it as you would your car.

Tune up- plugs gapped properly, cap, wires, rotor if applicable, timing, good filters. All parts are available at auto parts stores.

 

[Bizsoft]

Thanks!

 

[KnotYet]

Thanks!

In the meantime you could swap wires with the good engine to see if fixes anything.
If they have separate coils you can try swapping those.

 

[menzies]

It’s a basic gas v-8 engine, and treat it as you would your car.

Tune up- plugs gapped properly, cap, wires, rotor if applicable, timing, good filters. All parts are available at auto parts stores.

Yep, GM big block.

And run your blowers - 8 minutes, before start, always!

 

[sunchaser]

Assess which cylinder is missing by pulling individual wires. Once identified replace that wire, Check that a good spark is at that wire, do a compression check on that cylinder and check the cap "bad cylinder" location very carefully. How many years on the exhaust risers? It could be a valve problem.

 

[tiltrider1]

You have done cap and rotor. Next do plugs and wires. Then it’s time to check the timing. After that we need to know what type of distributor you have. You did not mention points so I’m guessing electronic but there are plenty of ways for the electronic distributor to fail after 40 years.

Start with the easy stuff. Wires go bad so it might be that simple.

 

[magna 6882]

also look at the engine running in the dark. Very common for high voltage spark plug wires to jump to ground causing a voltage loss to the plug.You can see the spark in the dark.

 

[Lepke]

Take a compression test. A burnt valve or bad cylinder can act like a miss.
Switch the ignition wire of the suspected cylinder with another cylinder, later swap the plugs. If the miss moves it's the wire or plug. If the miss doesn't move it's the cylinder.
Or take a long screwdriver. Put the pointy end on the exhaust port, the handle against our ear, you can hear the cylinder fire or not by comparing to adjoining cylinder.

 

[BeeJay]

Hey Guys,



I have 1980 Uniflite 42 DC with twin 454 Crusaders. The port motor has a pretty bad misfire issue. I replaced the cap and rotor, no change. I want to replace the spark plug wires (plugs are also new) but some folks have said that some of the available wires don't work well or are mis-sized. Looking for advice on the manufacturer and where to get the new wires. Thanks in advance for your help. Stay healthy!



- Dave G.

Hi Dave,
I would check the resistance of the HT leads that you already have. Plug them into the cap and measure between the cap and the plug end. They will all be different but any bad ones will stick out like dogs bollocks. I would do the same if replacing them for new. Someone else has advised on checking for a leak to earth and the method . As mentioned It’s a good idea doing it in the 1/2 light so its easier to see. If you use a screwdriver with a nice insulated handle and clamp a jumper lead to it, and clamp the other side to earth, then run the screwdriver over the leads and look for the light show. Please ensure that there is no fuel vapour about or else you may get a bigger light show than expected. Especially take note where the leads would come close to an object (like an engine cover) and where they are clamped or supported as it’s a likely place for a leak.
It sounds that you have satisfied yourself that the problem is the HT leads, but if not with a bit more information the petrol heads on here will get you sorted. Oh - and measure the coil leads as well.

 

[boomerang]

The first and easiest thing to do is verify that the firing order is correct. It's very possible the the engine starts and runs reasonably well with 2 cylinders misfiring. I hate to admit this ,but many many years ago I had a big block Chrysler 440 in a boat. I pulled the engine and did a rebuild on it, including head reconditioning. When I reinstalled it, it started and ran ok. It was a Chesapeake Deadrise so I didn't normally cruise it at a high RPM. It never sounded quite right at idle and when I increased the RPM's the misfire became noticeable. I started second guessing my self & rebuilt the carb, replaced the ignition components and even the cam (a big pita). Still no difference. The whole time, I was reinstalling the wires in the same incorrect position. When I finally found my dumb mistake, I was so elated that the engine ran like it was supposed to run, I didn't care about the time and expense I put into it!

 

[rslifkin]

454s use the 1-8-4-3-6-5-7-2 firing order. 5 and 7 are right next to each other, so it's easy to get them swapped. Doing that will cause a miss. Been there, done that on other engines with that firing order.

 

[menzies]

also look at the engine running in the dark. Very common for high voltage spark plug wires to jump to ground causing a voltage loss to the plug.You can see the spark in the dark.

This is why I changed mine out - though the engine wasn't noticeably misfiring I saw a black burn mark on the the block by a wire on an ER check. Started it up and watched to see the arc. Not good on a gas boat with 320 gallons on board! So I changed them all out.

 

[GH41]

It is NOT a car engine. It is a car engine converted to a marine engine. Many of the ignition and fuel components are explosion proof.

 

[rslifkin]

It is NOT a car engine. It is a car engine converted to a marine engine. Many of the ignition and fuel components are explosion proof.

Yes, but the basic operating principles are still the same. And the plug wires can still fail and arc.

 

[Pau Hana]

It is NOT a car engine. It is a car engine converted to a marine engine. Many of the ignition and fuel components are explosion proof.

There is no magic to a gas engine in a boat- the troubleshooting methodology is still spark/fuel/timing. A basic misfire can be traced to one of these 3 areas, unless a cam lobe is wiped, a timing chain has worn, or there are other other internal engine problems.

 

[Pete Meisinger]

Here is the secret to replacing plug wires.

Buy the most expensive wires you can find! (period, exclamation point)

pete

 

[Pau Hana]

Here is the secret to replacing plug wires.

Buy the most expensive wires you can find! (period, exclamation point)

pete

Funny in that was a trade secret when I was building Buick Grand Nationals for the quarter mile- find the wire set with the biggest core to maximize energy transfer from the coil pack to the plug.

 

[GH41]

There is no magic to a gas engine in a boat- the troubleshooting methodology is still spark/fuel/timing. A basic misfire can be traced to one of these 3 areas, unless a cam lobe is wiped, a timing chain has worn, or there are other other internal engine problems.

I wasn't implying magic was needed. Just that you cannot go to NAPA and substitute many marine parts with automobile parts without assuming some risk.

 

[Pau Hana]

In the OP's case, spark plug leads are spark plug leads- and all are booted for ignition protection.

 

[GH41]

In the OP's case, spark plug leads are spark plug leads- and all are booted for ignition protection.

https://www.wholesalemarine.com/spark-plug-wires/ I never thought about them needing to be longer to clear the wet manifolds.

 

[MYTraveler]

I wouldn't listen to "some folks."

My last boat had twin 454 350s and those engines are great. And very popular,

And VERY rare. Were they big blocks or small? Actually, they must have been the even more rare mid-size block. You should have held onto that boat.

All joking aside, if you run the engine at night (ie, in the dark), you may be able to see bad wires arcing. And if you don't have electronic ignition, I would focus on the points and if they are pitted also check the ballast resistor.

 

[Comodave]

We bought a boat with a newly rebuilt gas engine that ran very poorly. The mechanic looked at it and swapped the firing order to the automotive order and it ran great. The shop that rebuilt the engine used an automotive cam instead of a marine cam so the firing order was changed.

 

[Mischief Managed]

And VERY rare. Were they big blocks or small? Actually, they must have been the even more rare mid-size block. You should have held onto that boat.

All joking aside, if you run the engine at night (ie, in the dark), you may be able to see bad wires arcing. And if you don't have electronic ignition, I would focus on the points and if they are pitted also check the ballast resistor.

I suspect he meant 454CI engines with 350HP.

 

[menzies]

I suspect he meant 454CI engines with 350HP.

What else would it have been?

 

[RonR]

You know I was fighting what I thought was the same issues. I thought for sure it was some kind of ignition problem. New Cap/rotor/wires/plugs... same issue. I checked every wire against the firing order standard and reverse engines. Our engines have low hours so I did not think it was a carb issue. Boat would run fine just enough for me not to pull the carb. But I never could find any stand out problems with the ignition. The miss was always on the same side of the engine, pulled each plug and never really could pin point one cylinder that had the problem, seamed all of the off side were not running right. Pulled the carb off and it was very clean inside. Tore it all apart installed a new kit after a night in the dunk tank and a heavy blow down and clean.. Runs great now! I decided to also pull the other carb and do the same just to make sure there was no junk in it.