Jeff24SST

Just replaced my disaster of a cap and rotor last night. The boat idles alot smoother with alot smoother throttle response. So THAT problem appears to be solved.

Now what I have is a distributor that seems to be vibrating an awful lot. I'll describe it as a light shaking when I have my hand resting on it. I have never felt this before. It doesnt seem normal. The engine is rock solid with no vibs as is the outdrive. The vibs are not coming from anywhere but the distributor. There is no play whatsoever in the distributor, it is tight. Its a 95 efi 454 motor that was rebuilt last year. Could the dist gear be worn? has anyone experienced this?

Mr Gadgets

I would look at the cap terminals to see if the rotor is hitting it. Also is there any advance mech that could cause it.. Is the cap on the base? Is the base loose from the dist housing.. MSD sometimes has a removable base.. Just thinking outloud..

Hope it helps.

D*ck

BadDog

Should not take but a minute to pull the dist. and check the gear. Also check the gasket at the dist. base to see if perhaps it is too thick, that will set the dist. in at an angle when you tighten it.

David Stotz

I had this happen to two Mercruiser Distributors. The shaft rotates in a bronze bushing inside the housing and the bushing would wear causing the shaft to wobble.

trips2win

had the same on one of mine, replaced it.

SB

iTrader: (1)

Your motor should have the late model external coil distributor GM uses on '88-95 EFI vehicles. With many miles, it is common for them to wear out between shaft/housing. This causes wobble and sometimes spark scatter.

Good news is, the distributor (marine and vehicle is same distributor) is pretty cheap thru GM. Example:
http://www.sdparts.com/product/11039...stributor.aspx

If you installed cap and/or rotor incorrectly, yes it can cause shaking, but should also make loud noises as rotor + cap terminals would be contacting.

I have not felt a distributor while running in about 15 years due to way too many times being shocked by ignition. Last time it happened the spark went out my elbow to the firewall of a car that had MSD 6AL . Swore never to touch a distributor again while engine running...and never have since. Doh !

So I can't help with how it should feel while running. LOL.

Brandon

Man, now that there is funny! I'm only laughing at you cause I have been shocked so many times it isn't even funny. Last time was while diagnosing a running problem on my boat last weekend heading to the Shootout.

Jeff24SST

Thanks for the replies. It turned out to be the result of me being an idiot and not pushing the rotor all the way in. I pulled the dist and it looked fine. The cap was seated fine, but when I pushed down the rotor it had another half millimeter or so left to go. The rotor was barely kissing the terminals. luckily I only ran it for about a minute before I felt the vibration or it would have been back to the parts store for me. The copper strip on the rotor was bent down slightly. Bent it back and she runs like a raped ape! Whew, relatively easy fix.