pop-out solenoid on the top of the governor

[ammfarmer]

hey ive got an 87 f350 6.9l idi and it runs great but it stalls when you let off on the throttle fast. I think the little solenoid that holds it at a fast idle for a few seconds to prevent the stall isnt popping out. Could i be right? Thank you

[CDX825]

Thats the cold idle solenoid your thinking of. Its only on till the coolant reaches 120 degrees to help warm up the engine quicker.

[M.L.S.C.]

Your IP is getting slimy inside, and the low-revv governor thingie can't catch the rpms quick enough to recover from a quick throttle release. Pull your fuel filter and empty the fuel inside it, refill the filter with a cleaning chemical like Diesel Kleen and reinstall filter, then fire up truck and let her run for 20 seconds and shut her off - this gets the cleaning solution inside the IP and injector lines. Let the truck sit for a few hours, then fire her up and drive her like you stole her for a few miles, should clean all the junk out of the injection system. It's recommended that you warm up the engine very good before you do all of this, as a warm engine is much easier to restart even if you manage to get some air in it that a cold engine will be.

[cdnsarguy]

Do a pressure and flow test of the fuel pump at the Schrader valve on the filter header (FSS- fuel shutoff solenoid disconnected on IP). Remove the tire valve core and hook a hose and pressure guage on it should see 4-6 psi when starter cranking engine over. Then do a fuel quantity test same place, should see 1/3 pint in 10 seconds of starter engine cranking, route fuel to a suitable container with a hose. When all finished hook up the FSS wire .

If there is a problem with the lift pump and you are changing it, ensure the new pump comes with instructions as to correct installation procedure if it is the newer model pump with the almost straight arm.

[M.L.S.C.]

Pete, inability to recover from a throttle snap-back shouldn't be related to the lift pump at all, if anything a bad lift pump would present itself at higher engine speeds...

[Evel486]

Ditto. The IP is getting tired. Try MLSCs suggestion. If that doesn't work turn the low idle up to 700 rpm. If that doesn't work turn the guide stud in 1/4 turn. Guide stud is at rear of pump just above the high pressure outlets. 3/8" head screw with 1/2" lock nut. It may have a seal wire on it.

[cdnsarguy]

Pete, inability to recover from a throttle snap-back shouldn't be related to the lift pump at all,

Any diagnosis of a fuel system problem should follow a pattern, I usually start at square 1 and work up. Doing a history ie how old is the IP would be my next question. The TSB re stalling at stop signs and decelleration would be my place to start.

MLSC's comment....

Your IP is getting slimy inside,

Is the best lead to the IP problem, but you need to view the insides of the IP BEFORE adjusting anything other than idle RPM level.

If ammfarmer would like the IP TSB please feel free to PM me your email addy so I can forward that info.