RickB
Yoda
Offline
I got my 1980 MGB with this Crane Cams XR700 Fireball electronic ignition already installed.
Coincidentally the head has the infamous crack back around cylinder #3 just above the distributor.
I have a new head and dual carbs and early exhaust and plan to change it all out next month, just running as is for now.
When the engine is warm and it leaks back at the cracked area it's coolant that escapes, when hot this can take the form of steam.
In direct line on the inside fender is where the Crane XR700 is mounted.
Yesterday I could not get the car to start, it's like it just wasn't getting enough spark.
I have a spark tool I connect inline with the spark plug wire and it was showing a very weak spark.
The car simply wouldn't start, the starter (newly replaced) was working great, the battery was fully charged and the carburetor was getting gas.
It was very wet outside, it was in fact raining on me while doing the troubleshooting.
Eventually I gave up and went inside to get dry.
This beautiful morning the air had cleared, there was a light breeze, and the crescent moon was up above shining brightly.
Everything had dried out.
I thought I'd go ahead and give it a try, I said to my wife: I'm going to see if by some miracle it just starts this morning."
I put the key in and turned and the engine immediately came to life.
Thanks for sticking with the story so far, I know I've posted a few times already about these problems and I think I may be closing in on the actual cause.
If the XR700 gets wet and stays damp maybe it doesn't work until it drys out?
I know this is true with most electronics.
It can't dry out until the relative humidity allows that to happen.
The last time this occurred badly was also a very rainy night and after the engine had heated to the point that the crack had let out coolant and steam.
Eventually I got it to run and made it home, but it wasn't fun.
IF - and that's a big "if" because this has been a lot of guesswork so far, but IF this is the problem then replacing the head is the obvious solution.
For the short term, until I get a week off in March to do the work, I plan to figure out some way to protect the ignition components from the wet.
Hopefully I'll see a big difference (like it will start up and run all the time) and that will confirm I have the right solution.
There's also no grommet where the wires enter the distributor, I need to make sure that's sealed so coolant vapor doesn't enter there.
Coincidentally the head has the infamous crack back around cylinder #3 just above the distributor.
I have a new head and dual carbs and early exhaust and plan to change it all out next month, just running as is for now.
When the engine is warm and it leaks back at the cracked area it's coolant that escapes, when hot this can take the form of steam.
In direct line on the inside fender is where the Crane XR700 is mounted.
Yesterday I could not get the car to start, it's like it just wasn't getting enough spark.
I have a spark tool I connect inline with the spark plug wire and it was showing a very weak spark.
The car simply wouldn't start, the starter (newly replaced) was working great, the battery was fully charged and the carburetor was getting gas.
It was very wet outside, it was in fact raining on me while doing the troubleshooting.
Eventually I gave up and went inside to get dry.
This beautiful morning the air had cleared, there was a light breeze, and the crescent moon was up above shining brightly.
Everything had dried out.
I thought I'd go ahead and give it a try, I said to my wife: I'm going to see if by some miracle it just starts this morning."
I put the key in and turned and the engine immediately came to life.
Thanks for sticking with the story so far, I know I've posted a few times already about these problems and I think I may be closing in on the actual cause.
If the XR700 gets wet and stays damp maybe it doesn't work until it drys out?
I know this is true with most electronics.
It can't dry out until the relative humidity allows that to happen.
The last time this occurred badly was also a very rainy night and after the engine had heated to the point that the crack had let out coolant and steam.
Eventually I got it to run and made it home, but it wasn't fun.
IF - and that's a big "if" because this has been a lot of guesswork so far, but IF this is the problem then replacing the head is the obvious solution.
For the short term, until I get a week off in March to do the work, I plan to figure out some way to protect the ignition components from the wet.
Hopefully I'll see a big difference (like it will start up and run all the time) and that will confirm I have the right solution.
There's also no grommet where the wires enter the distributor, I need to make sure that's sealed so coolant vapor doesn't enter there.