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Re: Hot won't start issue Posted by Gary Stottler [Email] (#1463) [Profile/Gallery] (more from Gary Stottler) on Mon, 20 May 2013 15:11:01 In Reply to: Hot won't start issue, Stephen, Sat, 18 May 2013 21:03:58 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Agree with Jimmy, usually in CIS cars (Mechanical Fuel Injection - 1975-1980)this problem is caused by the fuel system losing "resting" pressure when the engine is shut off. As mentioned, when the system loses pressure then the 4 injector lines are full of vapor instead of liquid fuel and it can take 30-60 seconds of cranking to refill the lines in extreme cases. It was pretty bad in 1975-1977 cars and there was a service kit that basically started pulsing the cold start injector if you cranked more than 5 seconds or so with a hot engine. The injectors are a common leak path (although if it won't start at all, I would look at the other items I'm going to mention - usually leaky injectors will cause it to start on 2 or 3 cylinders because only one or two injectors are leaking. But, it is possible that all 4 are leaking).
There is a check valve in the fuel pump that can start leaking and cause the resting pressure to bleed down. In '78 and later pumps, the check valve was replaceable, but I don't know if the valve is available any more short of buying a new pump. There is also a leak path through the Warm Up Regulator/Control Pressure regulator in '75-'77 cars. '78 and later cars have a check valve in the fuel distributor to prevent that leak. Also, '78 and later cars got a larger accumulator (on the side of the fuel tank) so they can tolerate a bit more leakage without losing pressure. The best bet is to get a set of fuel pressure gauges on it and see if you can isolate where the pressure is bleeding off.
You could hook up the cold start injector to a push button and give it a manual shot of fuel when cranking also.
Good luck!
Gary
posted by 198.208.15...
_______________________________________ Gary Stottler
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