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Engine dies after being run for a while

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dockwrecker

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"I have a 1986 454 FWC engine

"I have a 1986 454 FWC engine which starts well, idles well, and runs well for about 15-30 Minutes. Afterwards, it dies and wont start. after a 15 minute wait, it starts and runs for another 5-10 min before stalling again.

I checked spark plugs, rotor, has good compression, my other engine runs on the fuel with no problems (so no fuel issue).

Any ideas?"
 
"Elan,

Sometimes it's t

"Elan,

Sometimes it's the ECU for the motor in question.
( Electronic Control Unit )

Also called the brain box

You can swap ECU box side to side, and see if the other motor now has the same issue. That way you don't have to waste money on parts.

Will work for testing the coil too. Just swap one motors part to the other.

Hope this Helps


"
 
Pop the distributor cap off an

Pop the distributor cap off and look for moisture.A couple of drops of water will allow you to start but when it heats up & turns to vapor it shuts you down.
 
"don't worry about the ECU

"don't worry about the ECU - an '86 won't have them as standard equipment.

The coil is a good candidate. A thorough inspection of the distributor cap may be in order. New ones do get cracked...

Can you clarify the fuel statement...common fuel tank or separate fuel tanks? If common tank, independent pickups?"
 
"Thank you.

For the fuel st

"Thank you.

For the fuel statement. There are seperate tanks. We have valves which enable us to run on either tank.

We ran both from the Starboard tank as well as well as both from the Port tank. In both cases, Starboard engine ran great, but Port has same problem in both configurations."
 
"The ignitor in my distributor

"The ignitor in my distributor recently did this. The other item is, as mentioned before, the coil."
 
"If the OEM distributor &

"If the OEM distributor & coil are still in, you can add ballast resistor and connections to the list to check."
 
"Elan:

With problems like t

"Elan:

With problems like this, you have to be pro-active. Next time it happens, pull the coil wire from the distributor, ground it to the manifold, and have someone crank it over. If you don't see a huge blue spark that will jump 1/2 inch, then ignition is your problem. If it does, then start looking for carb flooding, choke closing when it shouldn't (mine does that), and etc. But you got to narrow the field down, and checking for spark is the easiest way to do it.

Jeff"
 
"Elan,

The ECU is the elect

"Elan,

The ECU is the electronic ignition's brain

On Crusader 86 454's it depends on the distributor used on the motor,if it's a Chevy Delco type, then it's electronic... Containing an (ECU)or more commonly known as the ignition module.Mallory distributor's were a traditional points type ignition.

Crusader Marine
==================

Model 350 - 454 CID - Mallory Distributor Assembly
Mark-4 Block with 2-piece rear seal ( Non Electronic ) points type
Serial #'s up to 88710

Model 454 -Delco Ignition
Gen V Block carbureted engines ( ECU Type & part # 38068 ) electronic ignition ECU
Serial #'s from 88710 and up

Model 454XLI - TB454XL - 454 CID -Delco Ignition
Throttle Body Injected Engines ( ECU Type & part # 38068 ) electronic ignition ECU
Serial #'s from 92882 and up

Depends on your serial #

makomark, may be correct about them not being standard equipment. Most that I have seen though have been the AC/Delco electronic types.

You will just have to pull your dist cap and check.

diver dave- said that was what happened to his ignition module,and i've replaced more than a few at our marina.

Hope this gets you closer !"
 
"Thank you everyone!!!

I di

"Thank you everyone!!!

I did a few items, but changing the coil was the most likely candidate.

I also cleaned out the cap and rotor (Prestolite IDU-7801B 8L) and have ordered a new set from this website (for some reason, the local automotive stores cant find the parts, and the pic on this site matches).

Cleaned out the spark plugs, and reset all gaps.

I also used seafoam. Put about a shot glass full in the vacume line on the carborator…. (a friend suggested that).


After all that, it did run better but still stalled. I then replaced the coil, and whalla! Runs much much better, and also made an hour trip at 3200-3400 rpm with no hiccups.


Thanks again to everone!.... This site sure has been very helpful…

Elan"
 
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