'85 Fuel Pump runs without key
if you purchase a ZR13 auto code scanner, from HF,
you need this info
DOWN-LOAD AND PRINT IT OUT!
https://manuals.harborfreight.com/manuals/63000-63999/Q63806.pdf
https://manuals.harborfreight.com/manuals/63000-63999/63806.pdf
as usual start by getting a shop manual and a multi meter, and pulling the trouble codes
a logical step by step approach will lead you to the problem, you'll be amazed at what you'll learn reading links. use of a shop manual and multi meter can be very helpful
http://www.harborfreight.com/5-in-1-dig ... 98674.html
https://www.summitracing.com/parts/anm-cp7838
and rev the engine a few times and watch the fuel pressure it should in theory remain in the 38 psi-42 psi range for most TPI and TUNED PORT efi
a vacuum and fuel pressure gauge is useful
obviously an electric fuel pump in the fuel tank running is connected to a current source
you should logically be able to locate the source of that current by either pulling the fuses to any component that it might be related too. or tracing the wire feeding the pump back with a multi meter.
BTW it generally helps if you post the city and state your in,
as theres at least some chance a local member,
may want to stop by and help you diagnose,
and maybe help rectify the issue if your LOCAL
with the 1984 and newer computer controlled corvettes, you really need a old computer, an ADL cable and matching software to read the trouble code info and of course a shop manual for YOUR YEAR CORVETTE, and a MULTI METER
reading links may seem like a waste of time , but having a shop manual, a decent up-to-date, scan tool and a multi meter and a good understanding of what your testing and why your testing it helps a great deal
like the old saying how do you eat an elephant ?......one little bite at a time!
all the answers are readily available, theres known testing procedures and listed test results you can expect, and procedures listed in the shop manual for isolating and testing components, you don,t need to be a genius, you just need to be logical and persistent and not afraid to learn new things while getting your hands dirty at times, don,t get overwhelmed , break everything down too easy individual problems and tests, verify and test all the sensors,and test for factors like consistent fuel pressure, known temps,expected voltage or ohms resistance, and vacuum readings and don,t randomly start replacing parts as that gets expensive and its rarely the most efficient way to eliminate problems(unless you get really lucky) with modern computer diagnostic software you,ll have some advantages but think logically, most automotive problems still concern, compression, fuel delivery ,fuel pressure, vacuum, temperature or electrical issues.
and posting clear pictures of each spark plug labeled as to its cylinder number,
doing a vacuum leak test,do a fuel rail pressure test
do a compression test getting the compression number from each cylinder
check voltage on the coil input lead and alternator
http://www.helminc.com/helm
Measured Value
Engine Coolant Temperature Sensor. 185 Ohms @ 210F, 3400 Ohms @ 68F, 7,500 Ohms @ 39 F.
Engine Oil Temperature Sensor. 185 Ohms @ 210 F, 3400 Ohms @ 68 F, 7,500 Ohms @39 F.
Oil Pressure Sender/Switch. 1 Ohms @ 0 PSI, 43 Ohms @ 30 PSI, 86 Ohms @ 60 PSI.
Fuel Quantity Sender. 0 Ohms @ Empty, 45 Ohms @ 1/2 Full, 90 Ohms @ Full.
MAT (Manifold Absolute Temperature Sensor). 185 Ohms @ 210 F, 3400 Ohms @ 70 F, 15,000 Ohms @ 40 F.
Outside Temperature Sensor. 4400 Ohms @ 60 F, 2200 Ohms @ 85 F.
In Car Temp Temperature Sensor. 4400 Ohms @ 60 F, 2200 Ohms @ 85 F.
MAF (Mass Air Flow) Sensor. .4 Volts @ idle, 5 Volts @ Full Throttle.
Oxygen (O2) Sensor. .1 Volt Lean Mixture, .9 Volt Rich Mixture.
TPS (Throttle Position Sensor). .54 Volts Idle, ~ 5 Volts Full Throttle.
Sensor Locations
Sensor
Location
Engine Coolant Temperature Sensor. Front of engine, below Throttle Body.
Engine Oil Temperature Sensor. Left rear of engine, just above the oil filter.
Oil Pressure Sender/Switch. Top, left hand rear of engine.
Fuel Quantity Sender. Top of fuel tank, beneath filler pipe escutcheon panel.
MAT (Manifold Absolute Temperature Sensor). Underside of manifold air plenum at rear.
Outside Temperature Sensor. Right side of engine, top right corner of radiator.
In Car Temp Temperature Sensor. Coupe: above left seat near interior courtesy light, Convertible: center of cargo compartment lid.
MAF (Mass Air Flow) Sensor. Front of engine ahead of throttle body.
Oxygen (O2) Sensor. Left side of engine, in exhaust pipe.
TPS (Throttle Position Sensor). Right side of throttle body at the front.
useful related info
http://garage.grumpysperformance.co...ard-starting-tpi-crossfire-or-lt1-vette.1401/
http://garage.grumpysperformance.com/index.php?threads/code-scanners-software.3096/#post-18612
http://garage.grumpysperformance.com/index.php?threads/adjusting-your-tps-and-iac.168/
http://garage.grumpysperformance.co...-system-trouble-shooting-flow-chart-info.596/
http://garage.grumpysperformance.co...too-common-questions-can-be-found-here.12892/
http://garage.grumpysperformance.co...eight-trouble-code-scanners.11056/#post-49140
http://garage.grumpysperformance.com/index.php?threads/odbii-scanners.9697/#post-36100
http://garage.grumpysperformance.co...ittent-cylinder-miss-problem.9478/#post-34812
http://garage.grumpysperformance.co...an-obdii-reader-analizer-ect.8136/#post-29345
http://garage.grumpysperformance.co...h-flicker-on-dash-and-radio.13593/#post-70202
look at the diagram below.
http://garage.grumpysperformance.com/index.php?threads/replacing-a-c-4-fuel-pump.33/
http://garage.grumpysperformance.co...lay-switch-locations-and-info.728/#post-54562
http://garage.grumpysperformance.co...le-shooting-flow-chart-info.11536/#post-71845
http://garage.grumpysperformance.com/index.php?threads/1992-corvette-runs-like-crap.14198/
https://www.harborfreight.com/catalogsearch/result/index/?dir=asc&order=EAScore,f,EAFeatured+Weight,f,Sale+Rank,f&q=zr13My 1985 Corvette's fuel pump started to run on its own (without the ignition on). I did internet searches that pointed to the oil pressure switch as the culprit. Disconnected the plug from the oil pressure switch but the pump still runs. Removed the 10A fuel pump fuse and that didn't stop it (there's still power to the orange wire in the oil pressure switch plug). I also have removed the fuel pump relay. I'm not very confident in my electrical sleuthing capabilities and I really don't know what to do next. My hope is that there's a suggestion from the Forum's electrical wizards that can get me onto a correct track. I'm a new member to the forum.
if you purchase a ZR13 auto code scanner, from HF,
you need this info
DOWN-LOAD AND PRINT IT OUT!
https://manuals.harborfreight.com/manuals/63000-63999/Q63806.pdf
https://manuals.harborfreight.com/manuals/63000-63999/63806.pdf
as usual start by getting a shop manual and a multi meter, and pulling the trouble codes
a logical step by step approach will lead you to the problem, you'll be amazed at what you'll learn reading links. use of a shop manual and multi meter can be very helpful
http://www.harborfreight.com/5-in-1-dig ... 98674.html
https://www.summitracing.com/parts/anm-cp7838
and rev the engine a few times and watch the fuel pressure it should in theory remain in the 38 psi-42 psi range for most TPI and TUNED PORT efi
a vacuum and fuel pressure gauge is useful
obviously an electric fuel pump in the fuel tank running is connected to a current source
you should logically be able to locate the source of that current by either pulling the fuses to any component that it might be related too. or tracing the wire feeding the pump back with a multi meter.
BTW it generally helps if you post the city and state your in,
as theres at least some chance a local member,
may want to stop by and help you diagnose,
and maybe help rectify the issue if your LOCAL
with the 1984 and newer computer controlled corvettes, you really need a old computer, an ADL cable and matching software to read the trouble code info and of course a shop manual for YOUR YEAR CORVETTE, and a MULTI METER
reading links may seem like a waste of time , but having a shop manual, a decent up-to-date, scan tool and a multi meter and a good understanding of what your testing and why your testing it helps a great deal
like the old saying how do you eat an elephant ?......one little bite at a time!
all the answers are readily available, theres known testing procedures and listed test results you can expect, and procedures listed in the shop manual for isolating and testing components, you don,t need to be a genius, you just need to be logical and persistent and not afraid to learn new things while getting your hands dirty at times, don,t get overwhelmed , break everything down too easy individual problems and tests, verify and test all the sensors,and test for factors like consistent fuel pressure, known temps,expected voltage or ohms resistance, and vacuum readings and don,t randomly start replacing parts as that gets expensive and its rarely the most efficient way to eliminate problems(unless you get really lucky) with modern computer diagnostic software you,ll have some advantages but think logically, most automotive problems still concern, compression, fuel delivery ,fuel pressure, vacuum, temperature or electrical issues.
and posting clear pictures of each spark plug labeled as to its cylinder number,
doing a vacuum leak test,do a fuel rail pressure test
do a compression test getting the compression number from each cylinder
check voltage on the coil input lead and alternator
http://www.helminc.com/helm
Measured Value
Engine Coolant Temperature Sensor. 185 Ohms @ 210F, 3400 Ohms @ 68F, 7,500 Ohms @ 39 F.
Engine Oil Temperature Sensor. 185 Ohms @ 210 F, 3400 Ohms @ 68 F, 7,500 Ohms @39 F.
Oil Pressure Sender/Switch. 1 Ohms @ 0 PSI, 43 Ohms @ 30 PSI, 86 Ohms @ 60 PSI.
Fuel Quantity Sender. 0 Ohms @ Empty, 45 Ohms @ 1/2 Full, 90 Ohms @ Full.
MAT (Manifold Absolute Temperature Sensor). 185 Ohms @ 210 F, 3400 Ohms @ 70 F, 15,000 Ohms @ 40 F.
Outside Temperature Sensor. 4400 Ohms @ 60 F, 2200 Ohms @ 85 F.
In Car Temp Temperature Sensor. 4400 Ohms @ 60 F, 2200 Ohms @ 85 F.
MAF (Mass Air Flow) Sensor. .4 Volts @ idle, 5 Volts @ Full Throttle.
Oxygen (O2) Sensor. .1 Volt Lean Mixture, .9 Volt Rich Mixture.
TPS (Throttle Position Sensor). .54 Volts Idle, ~ 5 Volts Full Throttle.
Sensor Locations
Sensor
Location
Engine Coolant Temperature Sensor. Front of engine, below Throttle Body.
Engine Oil Temperature Sensor. Left rear of engine, just above the oil filter.
Oil Pressure Sender/Switch. Top, left hand rear of engine.
Fuel Quantity Sender. Top of fuel tank, beneath filler pipe escutcheon panel.
MAT (Manifold Absolute Temperature Sensor). Underside of manifold air plenum at rear.
Outside Temperature Sensor. Right side of engine, top right corner of radiator.
In Car Temp Temperature Sensor. Coupe: above left seat near interior courtesy light, Convertible: center of cargo compartment lid.
MAF (Mass Air Flow) Sensor. Front of engine ahead of throttle body.
Oxygen (O2) Sensor. Left side of engine, in exhaust pipe.
TPS (Throttle Position Sensor). Right side of throttle body at the front.
useful related info
http://garage.grumpysperformance.co...ard-starting-tpi-crossfire-or-lt1-vette.1401/
http://garage.grumpysperformance.com/index.php?threads/code-scanners-software.3096/#post-18612
http://garage.grumpysperformance.com/index.php?threads/adjusting-your-tps-and-iac.168/
http://garage.grumpysperformance.co...-system-trouble-shooting-flow-chart-info.596/
http://garage.grumpysperformance.co...too-common-questions-can-be-found-here.12892/
http://garage.grumpysperformance.co...eight-trouble-code-scanners.11056/#post-49140
http://garage.grumpysperformance.com/index.php?threads/odbii-scanners.9697/#post-36100
http://garage.grumpysperformance.co...ittent-cylinder-miss-problem.9478/#post-34812
http://garage.grumpysperformance.co...an-obdii-reader-analizer-ect.8136/#post-29345
http://garage.grumpysperformance.co...h-flicker-on-dash-and-radio.13593/#post-70202
look at the diagram below.
http://garage.grumpysperformance.com/index.php?threads/replacing-a-c-4-fuel-pump.33/
http://garage.grumpysperformance.co...lay-switch-locations-and-info.728/#post-54562
http://garage.grumpysperformance.co...le-shooting-flow-chart-info.11536/#post-71845
http://garage.grumpysperformance.com/index.php?threads/1992-corvette-runs-like-crap.14198/
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