adjusting your TPS AND IAC

the symptoms sound a great deal like the fuel pressure regulator is defective,
you might also want to check,
exhaust back pressure as clogged catalytic converters cause issues,
and replacing the oil pressure switch near the base of the distributor is a good idea,
if its over 5 years old
what year is your corvette?

related and useful links, if your tracking down a TPI tuning,
or idle or slow start issue

http://garage.grumpysperformance.com/index.php?threads/gm-tpi-stalling-diagnosis.15194/#post-86991

http://garage.grumpysperformance.co...elay-switch-locations-and-info.728/#post-1242

http://garage.grumpysperformance.co...uble-shooting-flow-chart-info.11536/#post-783

http://garage.grumpysperformance.com/index.php?threads/fuel-pressure-regulators.635/

http://garage.grumpysperformance.co...eplacing-a-c-4-fuel-pump.33/page-2#post-75720

http://garage.grumpysperformance.com/index.php?threads/exhaust-popping.15379/#post-90371

http://garage.grumpysperformance.com/index.php?threads/c4-corvettes-fuel-system-info.67/#post-37351

http://garage.grumpysperformance.co...ther-efi-intake-manifold-info.431/#post-32491

http://garage.grumpysperformance.co...e-stock-tpi-engine-components.1509/#post-3459

http://garage.grumpysperformance.co...ng-tpi-crossfire-or-lt1-vette.1401/#post-3104

http://garage.grumpysperformance.com/index.php?threads/diagnoseing-tpi-lt1-problems.1241/#post-2648

http://garage.grumpysperformance.co...lay-switch-locations-and-info.728/#post-54562

http://garage.grumpysperformance.co...8mm-throttle-body-on-your-tpi.290/#post-54181

http://garage.grumpysperformance.co...ttes-cold-start-9th-injector.2861/#post-40275

http://garage.grumpysperformance.com/index.php?threads/can-you-get-there-with-tpi.10494/#post-44284

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If it pops and misses in a TPI Corvette WOT it's usually ignition.
They eat up spark plugs- worn out.
Install new plugs.
 
Grumpy likes. 045" spark plug gaps.
I have had best results with .035 plug gaps in mine.
Depending how fast you drive the gaps open up .010-020" after 10,000 miles.
I see up to .020" wider after 10k.
I drive fast.
 
Ill try that when i go out sunday, I was just amazed how much i needed to turn the idle screw in (opening the throttle) to even start car! Thanks for the tip
 
I fixed the 1987 Corvette Convertible this past Monday night.
Removed the broken TPS screws with Snap On Talon series pliers came out easy.
I set the TPS with my old Snap On MT2500 series scanner. Its the original and over 25 years old now still works flawless on old OB1 & up to present OB2 using Global settings.
Just no fancy modern screen.
Red Brick Scanners Old time mechanics like me call them.

Over 200,000 miles now on my Corvette. Near 175,000 miles by me pure abuse !
Most driving to Chicago 150 miles roundtrip daily for work in the past doing 100-150 mph !
Job interview tomorrow at a Famous Corvette Shop.
Taking my Old Corvette Stallion.
 
I prefer to set the TPS with a scanner instead of backprobing the TPS sensor.
Either way works but there is a voltage drop .2-.3 tenths through the signal output wire to the ECM and what the Computer actually sees.
TPI 350 runs more responsive for me .57-.58 vdc at idle setting.
When its running correct a stock E-prom TPI 350 Corvette will start instant within 1/2 second cranking.
It will idle right at 600 Rpm warmed up in park & 600 rpm in drive or reverse with your foot on the brake pedal hot.
 
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