Healey 100 after running

[remso]

Hi guy´s out there, hallo to everybody, i´m new in this forum.
I own a AH 100/4 since 13 years at that time bought in Houston!
Now I´m faced with something I can´t cure, After shut down ignition the cars still runs.
I checked already if there is any coal on the pistons, using high rate petrol, and all the things someone should do.
Any idea what can cause this???? Anybody with same problems ?? The engine is fittet with aluminium cylinderhead , M-cam....
Bets regards REMSO

 

[Skip & Lynne]

Try this when you are ready to shut it down leave the car in first gear and slowley let the clutch out untill it just starts to engage and then shut it down. This should stop the running on for you. Skip

 

[remso]

John,
idle speed is around 600rpm ignition is with strobolight on the mark in the middle of the 3 marks on the crankpulley.

 

[Jim MacDonald]

I let the clutch out slowly with the transmission in 2nd gear (heard somewhere along the way but can't remember when or why this is the best gear to use) when I shut it down. Hasn't solved the problem but cured the symptom. My car also has a 3/4 racing cam which can lead to run on.
Additional input on this issue by others would be appreciated as well.

 

[John Loftus]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by remso:
John,
idle speed is around 600rpm ignition is with strobolight on the mark in the middle of the 3 marks on the crankpulley.<hr></blockquote>

The 600rpm is about as low as you want to go. I'm not sure what the timing is supposed to be on the 100 or which marks are TDC, etc. I hope someone else will jump in with timing info for this engine.

I do know that I was having run on problems with my 3000 when I first got it. Adjusting the idle and timing solved the problem for almost all situations. I also use the 2nd. gear, slowly engage the clutch and turn off the key method to if necessary.

 

[Dave Russell]

Hi John,

I was hesitant to say anything about this subject, don't know if I can help. I do have a 100-4.

The stock engine has only one timing mark on the front pulley & it is at TDC. The other marks must have been added along the way & I have no way of knowing what they represent. I added marks at 10,20,30,& 40 degrees on mine when I had the pulley off.

The factory shop manual is notably silent on how to set the timing & just says to road test & set until pinging just starts. To complicate things, the centrifugal advance is very sensitive in the 600 to 1200 rpm range & makes it hard to accurately set timing at idle. Personally, I set for 42 degrees at 5000 rpm & let the idle timing fall where it may.(vacuum advance disconnected) It ends up somewhere around 12 degrees advance at usual idle of 900 rpm.
D

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by John Loftus:

The 600rpm is about as low as you want to go. I'm not sure what the timing is supposed to be on the 100 or which marks are TDC, etc. I hope someone else will jump in with timing info for this engine.
<hr></blockquote>

 

[John Loftus]

How's the ignition timing and idle speed?

 

[Dave Russell]

Remso,
As measured on the circumference of the pulley, it comes out around 21.5 degrees per inch. I would expect that static timing should be around 10 degrees BTDC. This would be at a point on the pulley which is .465 inches before the TDC mark.

You said earlier that the strobe showed it was firing at the center mark & said later that the center mark was at TDC. This would indicate that the timing is retarded from where it should be.

I'm not sure that the timing is the cause of run on. But if it is, retarded timing would be a more likely cause than advanced timing. A spark plug which is of too hot a heat range could be glowing & providing ignition but this would only occur imediately after a hard run.
D

[ 03-17-2003: Message edited by: Dave Russell ]

[ 03-17-2003: Message edited by: Dave Russell ]</p>

 

[remso]

Dave,
I checked out what the marks could mean. When the 1.Piston is on top the middle mark on the pulley is overlapping an arrow which is embossed on the timing cover. O.K this seems to be tdc and the static timing point. When I checked this with a regular bulb it looks like that the ignition is too early. Could that be a reason of running on?

remso

 

[jayarbee]

I know this won't solve the problem. I just want to add to the 'experience base'. I bought my first 100-4 in 1964 (BN2), when I was 18 yrs old. My car would sometimes run-on from the time I parked it outside my house till the time I got inside the house! At the time I thought it was funny and I just let it run. I was a little worried about the running backwards when it finally quit dieseling and decided that I should probably just let out the clutch and stop it from running. I tried everything to prevent the running on but never solved it. Stopping it with the clutch was quick and easy. BTW- it only ran-on when the engine and the weather was hot, like summertime. I live in southern California. I notice that nobody has a solution to this phenomenon, but there are lots of suggestions. I think maybe there is no solution. That makes the condition a 'feature', doesn't it? I'll probably find out this summer when I get my latest BN2 running.

 

[chopper]

It kind of cracks me up that I'm 45 now and find myself more and more saying "when I was a kid"......we had (still have) a 1950 Ford 8N Tractor with a 4 cylinder flat head that loved to diesel when shut down. It was traced to a stuck needle valve in the carburetor which just kept gushing out gas as she sat there running backwards. I would defintely suggest anyone with "run on" or dieseling check their carbs.

 

[remso]

Thank you thank you guys after 3 years of searching looking an d being totally frustrated ...I got t with your help!!!!!!!!!! It was the ignition timing. Instead if advance I retarded the point of "truth"
Thank you so much!!!!!!!!!!