454 94'454 stall again, after change fuel pump

[Tom_1991]

Golden Gate Bridge, what a perfect place to have your vehicle stalls on. 

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This is not the 1st time it stalls, see:

94' 454 stall while driving and knock sound under the cab

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Before this fault down, I have changed the fuel pump (thanks to <riverbanks>), the original one is weak, I can easily block the fuel pipe with thumb, I think it is almost fail. Changed a new one, very strong, I can't block the fuel pipe with thumb.

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Model= 1994 Chevy Suburban K2500 Silverado

Engine= 454 TBI

Transmission= AT

Fault down des. :

    Location= Veterans Blvd. tunnel NB, Golden Gate Bridge(GGB) NB, Alexander Ave. NB, Calif.;

    Transfer case pos.=2H

    Coolant temp.= around 210(heated up), normal operation temp., enough;

    Engine Oil= normal pressure, enough, just changed (incl. filter);

    Trans. oil= enough, just changed(incl. filter);

    Fuel= enough, #87 from Chevron or Shell, I only fuel my vehicles in these 2 brand, I've burnout old fuel, now is new fuel in tank;

    Symptom= engine stall, hear knock sound from under the cab.

        Veterans Blvd. tunnel: attempt to shift to N then crank, crank no start, stop on drive way (no emergency stop area) shift to P, crank, start, shift to D(O/D Off), continue the road.

        GGB: multiple time of stall, after some times of stall, found the engine sounds like intake or exhaust jammed, and very weak power.

        Alexander Ave.: stall when down hill with O/D off, but back normal later.

        Inspection at break down site: Air cleaner is okay, filter is new, fuel pump relay contact is okay.

        Inspection at home : OBD scanner get DTC 54 and 32.

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Current status=sounds like intake or exhaust jammed, and power is weak; when drive next to a wall or something, can hear the sound like bleed pressure of a tire, this sound can't be heard when the vehicle is not moving.

 

I gonna check ignition system, incl. distributor, coil, spark plugs and wires, to check if there are any bad contact, but I suspect bad contact can't cause this problem.

 

I am afraid one more thing have broken while on GGB .

 

Edited March 7, 2020 by Tom_1991

[riverbanks]

Combination of things,stuff happens,clean the egr,apply vacuum, check it's operation,could be it stuck a bit open,02 got a rich signal,leaned it up,gave you a hard start

[Tom_1991]

2 hours ago, riverbanks said:

Combination of things,stuff happens,clean the egr,apply vacuum, check it's operation,could be it stuck a bit open,02 got a rich signal,leaned it up,gave you a hard start

Thank you again.

Gonna inspect them tomorrow, I just drive it to pickup its ignition system parts from O'reilly, still hot now, and still weak power and dump air sound along the road.

According to my shop manual and actual vehicle, seems like its EGR valve is controlled by ECM directly (liner egr valve), no vacuum tube.

 

I almost tend to convert it into non-ECM carburetor system, since TBI is very similar to carburetor.

But I am afraid it is not so simple because the TCM (Transmission Control Module) may use data from ECM (like rpm, throttle position, etc.) to control shifting.

Edited March 7, 2020 by Tom_1991