Engine Performance problem
1993 Chevy Silverado V8 Two Wheel Drive Automatic 228000 miles
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Ok, here is the deal the other day I went to start my truck up. First try didn't start thought it was odd usually it starts on the first try. Second try started right up, drove it to work and parked it, later when I got off work went to start it and would not start up. At first I figured the fuel pump went out. So I had to tow it home, next day I replaced the fuel pump motor and strainer only, along with the fuel filter. Hoping it would start, It didn't It turns but will not turn over to stay on. I then sprayed the TBI with starting fluid and it started but was Idling real bad, none the less I stepped on the pedal to give it some gas when I would let go of the gas pedal it Idling bad still, I could see the gas shooting from the TBI into the carb but it was shooting in spurts not a constant flow. I thought that was strange. After awhile it would shut off and would not start on its own again. It was getting late so I figured I would work on it the next morning. Next morning I went and tried to start it once again, and to my suprise it started on its own when I turned the key. No problems at all was Idling perfect as if nothing had happend. I left it for awhile while warmed up, I then peeked into the carb again and I could see the TBI was shooting gas into the carb with a constant flow no interruptions at all. I thought maybe it would be back to normal again, then I decided to take it on a test drive down the freeway, drove it at around 65-70mph for a ways no problems up and down. When I came to a stop light after getting off the free way I felt a jerk like it wanted to shut off, but it stayed on good thing I was close to home.. when I pulled up to my house it just died on me no shaking no jumping just dead in drive. I then tried to start it up and it started but then it would die when I would put it in gear. Now I'm stumped. after a bit the temp gage went up close to 210 while the truck was off. that too was odd because I had changed the radiator a few years back to a larger one and it never got hot past 120 not even on hot summer days above 100 degrees especially when I would shut it off. So that was weird I thought. Then I tried to start it and it would not I looked into the carb and I'm not seeing any fuel coming from the TBI anymore bone dry!. I checked the codes and at first I got code 54 which according to the repair manual it states "Fuel pump Circuit (low Voltage) what ever that means. I don't have a clue on it. then I read somewhere about maybe the fuel pump relay switch which I replaced and still no luck, I ran the code test again and now I get codes 22 and 54.. 22 is for Throttle Position Sensor (TPS) circuit signal low voltage. again no clue what it means. Can someone please point me in the right direction as to how I can fix my truck. I really need it for work and I'm running out of options or clues. I'd can't really afford to take it in to the shop.. that would have to be last resort. This just all happened out of the blue no signs of it going bad nothing. Also I've heard mentioned something about the fuel pressure, How do I check it where do I look for it? Any and all help is greatly appreciated. Thank you!

Do you hear the fuel pump come On for 2secs? If so do a fuel pressure check the readings should be 9-13psi then comeback with the actual readings this is where we start-

Also measure the resistance of the injector should read 1.3ohms-I'll be waiting. The TPS can be a problem with the stalling too.

Chevy Man 22 wrote:

Engine Performance problem 1993 Chevy Silverado V8 Two Wheel Drive Automatic 228000 miles ---------------------------------------------------------------- Ok, here is the deal the other day I went to start my truck up. First try didn't start thought it was odd usually it starts on the first try. Second try started right up, drove it to work and parked it, later when I got off work went to start it and would not start up. At first I figured the fuel pump went out. So I had to tow it home, next day I replaced the fuel pump motor and strainer only, along with the fuel filter. Hoping it would start, It didn't It turns but will not turn over to stay on. I then sprayed the TBI with starting fluid and it started but was Idling real bad, none the less I stepped on the pedal to give it some gas when I would let go of the gas pedal it Idling bad still, I could see the gas shooting from the TBI into the carb but it was shooting in spurts not a constant flow. I thought that was strange. After awhile it would shut off and would not start on its own again. It was getting late so I figured I would work on it the next morning. Next morning I went and tried to start it once again, and to my suprise it started on its own when I turned the key. No problems at all was Idling perfect as if nothing had happend. I left it for awhile while warmed up, I then peeked into the carb again and I could see the TBI was shooting gas into the carb with a constant flow no interruptions at all. I thought maybe it would be back to normal again, then I decided to take it on a test drive down the freeway, drove it at around 65-70mph for a ways no problems up and down. When I came to a stop light after getting off the free way I felt a jerk like it wanted to shut off, but it stayed on good thing I was close to home.. when I pulled up to my house it just died on me no shaking no jumping just dead in drive. I then tried to start it up and it started but then it would die when I would put it in gear. Now I'm stumped. after a bit the temp gage went up close to 210 while the truck was off. that too was odd because I had changed the radiator a few years back to a larger one and it never got hot past 120 not even on hot summer days above 100 degrees especially when I would shut it off. So that was weird I thought. Then I tried to start it and it would not I looked into the carb and I'm not seeing any fuel coming from the TBI anymore bone dry!. I checked the codes and at first I got code 54 which according to the repair manual it states "Fuel pump Circuit (low Voltage) what ever that means. I don't have a clue on it. then I read somewhere about maybe the fuel pump relay switch which I replaced and still no luck, I ran the code test again and now I get codes 22 and 54.. 22 is for Throttle Position Sensor (TPS) circuit signal low voltage. again no clue what it means. Can someone please point me in the right direction as to how I can fix my truck. I really need it for work and I'm running out of options or clues. I'd can't really afford to take it in to the shop.. that would have to be last resort. This just all happened out of the blue no signs of it going bad nothing. Also I've heard mentioned something about the fuel pressure, How do I check it where do I look for it? Any and all help is greatly appreciated. Thank you!

Next time it refuses to start do below something has to give between the fuel and ignition system

Get a carb cleaner and spray into the carb or the throttle body on an EFI. Did it start and die? If not disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel problem, check the fuel pressure to rule out the fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light.

Fuel pump/Pressure Regulator and Injector/s checks out-start checking the ignition system-power to coil, coil/s itself,distributor pick-up,control module, Cam and Crankshaft sensors.

If both fuel and spark is present-check the valve and ignition timing, this will lead you to problems with compression and valves opening and closing at the wrong time

Ok , I think I may have found the problem, after replacing the IAC along with everything else I have mentioned before. The other day it started up just fine. Idle was fine left it running for about 30min then when I went to put it in gear it shut off again. Started right up again then tried putting it in gear again and shut off. After about the third try it would not start up, it just would crank but not turn over. I was curious to see if I was getting any spark to the plugs so I pulled one of the wires and had someone crank it while I checked for spark. Nothing no spark present, I tried a different wire and still no spark. Finally it donned on me It must be the IC ignition control module. So I went out and replaced it and it started right up. Still a little weary of it maybe shutting down on my I was reluctant to test drive it. So I let it warm up for about 20 min or so then got the courage to take it around the block and hope it didn't shut off on me. The only question I have now at this point is when I put my truck in gear what should the rpm be at? when it's in park it's around 1000k but when I shift it into gear it drops down to like 250-300rpm. And if I turn my steering wheel at that moment it sounds like it wants to shut off. I'm wondering if my idle in gear is set too low. Maybe when I put the new TPS I didn't set it right. Is that even possible? and if so If i adjust the TPS a little will that do the trick I wonder. If you can tell me what the rpm should be at when the truck is in gear that would help me out. And if you think that by adjusting the TPS will do the trick. Please advise Thank you for all your help. Very much appreciated.

Mike

Set it at 600 RPM- for the throttle position sensor voltage at closed throttle should be 1.25volts or less.

to set it do i just loosen the screws on the TPS and and turn it? with the truck on or off? or is there another way to set it at that rpm? thank you.

Turn the key to run and measure the voltage at the TPS and at the same time turn the TPS till you get 1.25volts or less. Unable to get the right reading-replace it

This problem sounds like it rears its' ugly head when the engine is warmed up -- clue?
If the TPS checks out OK, then check the ignition control module and the coolant temperature sensor. Just replacing these items is probably a good move -- considering you have 228000 miles on the truck.
The ground for the fuel pump commonly corrodes -- check it out also.