I have a 1979 450sel.Was running when parked up next day it would not start.Took off air cleaner,while cranking over I pushed that round flap thing down it started to run.I let it go it stopped.

SOURCE: crank no start

SOUNDS LIKE THE CRANK SENSOR POSS. AS I HAVE ONE HERE THAT I JUST DIAGNOSED FOR THE SAME THING WITH A SCAN TOOL WHEN WE FINALLY GOT IT NOT TO START. I'LL FOLLOW UP AFTER SENSOR INSTALL

SOURCE: 1997 jeep country will not start.

you may have a crankshaft or camshaft position sensor gone bad whitch could cause what you describe

Dar

• 2007 Answers
• Posted on May 21, 2009

SOURCE: 1998 mitsubishi mirage 1.5 liter 5 speed wont start

If you have spark, try changing the fuel filter. If you don't have spark, get back to me.

SOURCE: starts/stalls won't run until pedal tapped, 2

Check your IAC motor (Idle Air Control) It could be sticking open.
Ps. Might be called Idle Speed Control motor it depends on the make and i forget what chevy calls theres.

SOURCE: 1999 Chevy 3500 p.u. cranks, no-start 50 p.s.i.

Sounds like a fuel problem. If it runs when you spray carb cleaner your "fuel" may not have enough octane. I suspect you could have 50psi with a high water content (or the wrong fuel i.e. gas vs diesel?)...Drain the fuel and replace with fresh fuel (gasoline or diesel depending which engine you have), along with a bottle of fuel conditioner.