distributor cap won't stay on

[The_Handier_Man1]

From: Winnielover4078  (Original Message)
Sent: 5/30/2005 7:38 PM

    First off, we took our first camping trip since we bought dino back in november, I am happy to say everything went great. I was really amazed to see how how cool this thing ran between vegas and utah with the hot weather, never went over 205 on the gauge. My problem is, the distributor cap wont stay clipped on to the distributor, this has happened at least three times since we have had it. 413 engine. I even bent the little tabs to hold it tighter. Any suggestions? Thanks Kenny.



From: SeaRaySRV16O
Sent: 5/30/2005 8:56 PM

Time for a new cap maybe ??

Just a thought.

Regards,

Robert Donley
Jenison, MI



From: denison
Sent: 5/30/2005 9:49 PM

I find that replacing the cap on my 413 always takes a little care, and the retainers are hard to get clipped onto the hold-down lip.
Could the locating tongue or notch on the rim of the distributor body be burred slightly, or could the cap be a faulty molding? I bought a cap for my 32 Chevy that would not seat properly, being a smidgeon smaller in diameter than the mating rim. The next one I bought, which also said "Made in Brazil", fit perfectly.



From: poppinjohnnies
Sent: 5/30/2005 10:56 PM

I have found that the NAPA Echlin brand caps are of much superior quality than other parts store caps / ignition products.  They fit perfectly and have heavy duty brass contacts.



From: Winnielover4078
Sent: 5/30/2005 11:22 PM

    The cap is new, bought it from napa, the old cap and rotor were ruined when it popped off.  This time the cap was not harmed.....kenny



From: poppinjohnnies
Sent: 5/31/2005 12:32 PM

Maybe there is an excessive endplay issue with your distributor.  If the housing has excessive wear over the drive gear, it could cause the shat to "float" up and down and put too much pressure on the cap.  I have heard of this happening but I've never actually seen it happen.  You can check this by pulling up and down on the top of the dist. shaft.



From: Slantsixness
Sent: 5/31/2005 12:53 PM

This is an old problem, I used to run big blocks in hot rods for years. I've seen this happen quite a few times.

Wrong cap, (some aftermarket molds are too short at the skirt to fit properly use Borg Warner or Mopar if you can find one) (I've never had trouble with Echlin though...)

Bad cap,

Worn out distributor spring clamp(s) on the side, (they DO get bent, and it's not where you think, look at the top of the clip, where the clip goes into the cap tab!)

Bad or worn bushings in the distributor or the block (but that would make the engine run bad)

And the number one reason:

Crud or sludge buildup in the cap base mounting ring or around the key tab on the distributor or cap.

(By the way, is your dogbox cover hitting your distributor or the wires? a little torque movement of the engine and the cap will get knocked off, too.)

You do have BOTH clips, right?!!!! ( some people have never realized there were two!)

Tom



From: OldEdBrady
Sent: 5/31/2005 7:43 PM

Does the lip of the cap fit COMPLETELY over the distributor?  I bought one from a local place--no names, but they run from A to Z--and it was too small for the distributor.

(I actually typed "ruin" for "run."  I was tempted to leave the mis-spelling in.)



From: mbba1036
Sent: 6/1/2005 8:52 PM

i had a similar problem on the engine of my boat.After the boat sat for a little while, fuel vapors would travel from the body of the carb via the vacume advance line.The diaphram was faulty in the vacume advance and it would let gasoline fumes under the distibutor cap.When i went to start it, a tiny explosion from the rotor sparks would unset the cap. A new vacume advance solved it for me,also the PO of the boat had an automotive dist. cap on it, as a marine one has a little vent on it to prevent that from happening.