1993 Chevy Suburban Starts then quits

1993 CHEVROLET SUBURBAN
150,000 MILES • V8 • 2WD • AUTOMATIC
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DEVYN
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  • 3 POSTS
I'm having a problem with my suburban. When I start the vehicle it runs for about 30 sec to 3 min then shutsdown as if some one turned it off.

Its a TBI system. I've replaced the coil and ignition module so far just to get it to run for this amount of time. Before these were replaced it wouldn't start.

Now onto what i think is strange, after it dies I have to turn it completely off in order for the engine to start again. If I don't do this then the engine will continually crank without firing.

I've got fuel pressure. How much I'm not sure. I don't see a schrader(sp) valve on the fuel system to check it. I used a sort of back woods technique to see if I had fuel and it was to take the line off and route a hose to a gas can. I had pressure like you would find from a garden hose but nothing high pressure.

Any suggestions?
Jan 25, 2010 at 8:50 AM
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RACEFAN966
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So when it dies will it start back up? If not do you have spark then? If there is spark then is there fuel at thet time? Get back to me and we will go from there.
Jan 25, 2010 at 11:42 AM
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RASMATAZ
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Hi Devyn, Welcome to 2carpros and TY for tthe donation

Try this bypass the ignition circuit from the ignition switch by running a wire from the battery positive post straight to the coil positive terminal and attempt to start the vehicle- if it continues to run -replace the ignition switch-Let me know
Jan 25, 2010 at 11:46 AM
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DEVYN
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Ok I checked for power to the coil right after it died. I still have battery power. I also pulled the ignition switch (electrical part - key replaced last year) and checked all the electrical connections and it all tested good. I also went the extra step to verify the plugs, wire, cap, and rotor were all good and not corroded, fouled, or broken.

Now to checking the fuel. How do I check for fuel without turning the key off to de-energize the fuel pump? Because after the key is to the off position and then turned back on the pump runs again delivering fuel. There is no schrader valve on this fuel system that I can see to hook up a gauge. I can hear when I turn the key to the run position the fuel pump relay de-energizes the pump after a few seconds.
Jan 26, 2010 at 8:46 AM
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RASMATAZ
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When you turn key to run position the fuel pump will come On for 2 secs then the fuel pump relay de-energizes-no power at the pump Follow the instruction s below: TBI system


https://images.2carpros.com/forum/automotive_pictures/12900_fuel_pressure_check_TBI_2.jpg

Jan 26, 2010 at 9:31 AM
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DEVYN
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Well after i got the adapter installed to check the fuel pressure, the pump totally quit. I tried jumping it on full time but still no pressure. I changed the pump and its working.
Jan 27, 2010 at 11:59 AM
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RACEFAN966
  • ✓Experienced Mechanic
  • 5,029 POSTS
Great glad to hear it is running again as it should. Thanks for you support and have a great day.
Jan 28, 2010 at 2:11 AM
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