![]() |
My 351 Crate Motor has a miss
Hi Guys,
I am hoping someone can help me sort out a problem I'm having with my motor. I have a new 351 FMS crate motor that has a miss. When we first started the motor we used a rebuilt Holley carb with the following results: at idle there was a steady miss at about 700 rpm. when rpms were brought up slowly to 2000 the engine developed a sever stumble. A friend loaned me his Carter carb and after we switched out the Holley the miss and the stumble went away. What has me puzzled is the stumbled and miss has returned while still using the Carter. No other changes have been made. I also noticed some strange readings on my SW tach. At idle the rpms indicated on the tach jump around from 700 to about 2000 with no apparent change in engine sound. I'm using an MSD 6AL .. I'm wondering it this has something to do with my other problems. Any help would be appreciated. |
Just a wild guess....
You may have surmised this, but it sounds like an ignition/and or electrical problem. Do you have the computerized MSD ignition? Maybe it was fried or defective ? Maybe there is a crossed wire in the build? (I am assuming for the moment that this is a new build)
The problem mat have been compounded by the first carb ? But maybe you have half/fried a wire/the computer, in the meantime, so it came back? If it was mechanical, the problem would have been constant ? Just guesses, maybe someone else recognizes the exact problemo and can help:rolleyes: By the way, I never rebuild carbs, I buy quality rebuilt carbs and just drop the puppy on the motor. Did I mention I HATE carbs? My dad can rebuild them in his sleep, I HATE them :p |
Yes, check your wiring on the ignition in the steering column, ignition box etc. I saw my tach jump around like yours too. Turned out to be a burned pig tail plug in the column ignition.
Curt |
Sounds to me like it is an ignition fault.
I would check all wire terminals as Curt described. |
| All times are GMT -7. The time now is 01:07 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: