• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

BJ8 Rebuilt Engine and Carbs - Vapor Lock and Misfires when hot

Share this page

C

curly02161

Freshman Member
Country flag
Offline
This is a very frustrating issue and I have read other posts and threads.

67 Healey 3000 MK III BJ8

1. Engine was rebuilt and SU Carbs were rebuilt less than 2K miles on engine
2. Car ran very hot so installed electric fan to help cool. Also new radiator.
3. On hot days in traffic car will start to gasp ( vapor lockish) and occasionally misfire.
4. Took on long open road drive keeping at 3500 RPM. Ran well as i thought engine was staying cool.
5. Engine began to gasp/vapor lock and misfire after about 70 miles.
6. Once engine cooled off, I was able to drive again. But clearly unreliable.

I need some kind of order to troubleshoot this problem and ideas/tips as to what may be causing this?

Thanks
 
Re-check your timing and change the coil even if its new, its probably breaking down causing the misfire which too often is diagnosed as vapor lock.
 
I had exactly the same problem on the same model about 2 months ago. I reset TDC advanced as per the book, changed the points and solenoid. Checked the pump and fuel lines for fuel flow/starvation, cleaned the fuel filter and reset the float bowl height in the SU's. I still had the problem !!! The problem in the end was the plate in the distributor that was moving/oscillating as the bushes were worn.. I had the distributor rebuilt with new bushes and the problem went away..
 
I go with Andrew, give the distributer a good looking at, is there movement in the shaft, see if you can rock the top plate on the bottom plate - if the answer is yes then the sprung star washer under the fixed plate is damaged, advance the top plate by hand and examine the connections to the vacuum mechanism to see if there are any loose connections. Also look at the earth- (ground) lead from the condenser to the fixed plate screw. Examine the low tension lead to the points - if the insulation is iffy - suspect - get a new lead. Lastly examine the low tension lead on the outside of the dizzy back to the coil - see if the connections are sound.

Best of luck

:cheers:

Bob
 
Over time crud builds up around the weights and springs in the distributor and this prevents proper advance of spark. In which case, your timing is retarded and your engine will run hot. Check out your distributor.
 
Back
Top