Hi this is my first thread here . The problem is it will wont stay at any rpm more than approx 15 seconds before stalling. Idle approx 15 seconds then it will die 2500 ,3000 ,1500 the rpm does not matter the same result. If you constantly work the throttle it will stay running .Its not showing any engine codes just tranny codes . This is the list of parts that i have replaced and it runs exactly the same fuel pump, fuel filter, fuel pressure regulator,fresh gas and water remover, map sensor , tps,the last item was distributor, would have been cheaper if i had just taken it to a shop . cap rotor and wires are about one year old .I have had this truck about 10 years it has always ran perfect until about three weeks ago. I did notice if i unplug the map sensor it will stay running and it can be driven without stalling just not much power .Also when it dies it does not lose voltage to the coil,the spray from the injectors decreases as it dies.I bypassed the fuel pump relay so the fuel pump stays running and the fuel spray from the injectors still decreases as it dies. Any help would be great thanks
1994 454 4x4 k 2500 suburban wont stay running
- Thread starter dinky
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zora
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We have had this sort of thing a couple of times recently on this site. Have you tried changing the CTS,coolant temperature sensor, it appears to cause the system to run very rich when it fails. See the thread below
http://chevyforum.org/chevy-forums/showthread.php?t=29961
http://chevyforum.org/chevy-forums/showthread.php?t=29961
Suburbanized
New member
what about the engine ECU? the capacitors can be leaking.
Do you have a vacuum operated vacuum advance on the distributor? If so, perhaps the diaphragm inside is leaking and not allowing the timing to advance. If you don't have vacuum advance, then I don't have a clue as to what else it could be unless it's a throttle body problem.
I decided to check that my fuel pump is producing enough pressure so I got a tester from autozone .And my pump is only doing about 13 psi, and according to the info in the spec book that came with the tester it should be min of 26.I was unsure so I surfed the web and found that 7.4 454 1994 -95 (vin engine code N )had different size injectors so more pressure is needed . I am picking up a new pump and putting it in tomorrow had to order it .I hope this is it I will let you guys know.
Well I put in the new pump filter and sock,it stays running now but the idle goes from 900 to almost die for a minute then smoothes out and idles fine and drives fine. Shut it off wait a minute and restart it and it is rough then smoothes out again .EGR control solenoid maybe im not sure.But atleast it runs again getting closer .And fuel gauge does not work now the ground is on good too ,messed it up when it was out I guess.
Well I wanted to let everyone know my suburban would not stay running again .And I went the way many would disagree with .I had an old tired big block (the last engine that was in my jet boat )so I used the wiend intake and holley carb and the HEI dist and installed them on my burb .It was a basic swap out everything lined up fine ( My 454 is not a tall deck) .I had to use a bypass regulator .And make a bracket to hold the tps on the side of the carb. And I made a screw that fits in the carb shaft that is squared off to simulate the tbi shaft ,so when I gas it the computer operates the 4l80e. And a different relay for the fuel pump.The throttle cable was a little short but no biggie .And this thing is banging like a champ and more power than it has ever had and it shifts like it did before.