Flat spot... AGAIN!

Rincewind · Post by **Rincewind** » Thu Jun 14, 2007 10:49 am

A while back i posted that i was having problems with cold starts and flat spots with my new recon engine.. After some great advice from forum members i changed the main jet and thought i had fixed the problem.. Unfortunately this was short lived as soon i was experiencing the same problems as before.. Next i tried turning back the automatic choke but all that happened was the cold starts got worse.. Finally in desperation i changed to complete electronic ignition yesterday with a brand new dizzy, and thought all was wonderful! The engine ran better than ever.. But alas this morning when i started the car up, it took FOREVER to get going.. Then it kept stalling at robots and that f*%&ing flat spot is STILL THERE! Please, i've had about as much as i can take! If you guys have ANY more advice no matter HOW obscure please please please let me know!

Post by **Tony Z** » Thu Jun 14, 2007 11:28 am

get yourself a can of quick start...
when the engine is running (do this both when cold and warm), spray the quick start around all the places on the inlet system that you have a seal / gasket / joint. Under the Carb, at the manifold rubbers, at the head gasket.... listen to the engine. If it increases idle speed or changes in any way, you know that the area you are spraying at has a vaccuum leak. Fix that leak.

Post by **Tony Z** » Thu Jun 14, 2007 11:31 am

also spray around the carb to check the seals. Get a length of air hose to attoch to the carb inlet if needed to avoid the quick start going thru the carb and making you think you just found a leak, while in fact you just fed the stuff directly to the engine........

Rincewind · Post by **Rincewind** » Thu Jun 14, 2007 11:35 am

I'l pick some up on my way home tonight.. Thanks tony!

Post by **Tony Z** » Thu Jun 14, 2007 11:36 am

Cool.... good luck, let us know

Post by **IMPI** » Fri Jun 15, 2007 7:53 pm

Run a tank of unleaded through
Also check if the acc pump isnt too strong.
Armand

Rincewind · Post by **Rincewind** » Fri Jun 15, 2007 8:12 pm

Well today I did the vaccuum leak test and found a HUGE one where the carb joins the manifold. Took the carb off, filed the seating of the manifold flatter and changed the gasket. This didn't help, so took the carb off again and put some lock-tite on the gasket. The leak seemed to be gone but will know tomorrow morning for sure when I start her from cold!

IMPI, what does running a tank of unleadded through do?

Rincewind · Post by **Rincewind** » Fri Jun 15, 2007 8:13 pm

Thanks to Tony for his good advice!

Post by **Tony Z** » Fri Jun 15, 2007 9:09 pm

Merlin · Post by **Merlin** » Sun Jun 17, 2007 11:27 am

Rincewind wrote:IMPI, what does running a tank of unleadded through do?

It's catastrophic!

Causes global warming, cold wars, and unleaded-coated internals!

Rincewind · Post by **Rincewind** » Sun Jun 17, 2007 11:31 am

Ok here's the latest update.. The leak is still there and i can't think of anything else to fix it.. Ideas anyone?

Post by **Tony Z** » Sun Jun 17, 2007 12:29 pm

Its not a crack in the base of the carb is it? maybe one of the little screws has its O ring damaged...

lowlight · Post by **lowlight** » Mon Jun 18, 2007 10:03 am

Mate of mine hit the ears of the flange on the manifold so that it seals better ques effect is more or less same as filing

Post by **IMPI** » Tue Jun 19, 2007 7:41 pm

it seems to me that the aditive that replaces the lead somehow coats the inside of the plugs as well and makes it harder for them to fire .
It also seems to prevent the fuel from vapourizing so easily and a carb works on that principle
Other than that I dont know how it works but they seem to run better
Maybe its just wishful thinking.
A