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Discussion Starter #1
I did a complete tune-up, Plugs, Wires, Cap, Rotor, Fuel and Air Filters, PCV, Cleaned the Throttle Body and EGR Tubes, and checked the Timing at 10 Degrees BTDC. I still have these issues that are driving me crazy.

PLEASE HELP!!

ISSUE #1:
Connected my Fluke DVOM to the TPS connector and got these readings: 4.46 Volts at idle, and a steady reduction to 0.60 Volts at WOT. These readings seem to be the exact opposite of what I am used to.

Shouldn't it be about 0.55 Volts at Idle and about 5.00 Volts at WOT?!?!?

Can anyone set me straight!!! What is happening here??

More Importantly: How to properly adjust the TPS with a Fluke DVOM!! If it is adjusted only through the Diagnostics (Climate Control Center), then please give me step-by-step instructions.

Issue #2:
Set the Base Idle screw to 550 RPM with the ISC disconnected. Then I reconnected it and tried to follow the Relearn Instructions I found in this forum. Unfortunately, there are several different techniques that left me lost & confused. Can someone please explain step-by-step how to do it for a 4.9 L - '91 Deville.

Issue #3:
What are the Specifications for the 4.9L - '91 Deville Fuel Injectors?? Are they 18lbs/hr or 19lbs/hr, or ?????

THANKS!!!
 

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White Diamond '03 DHS (with DTS floor shift)
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86,785 Posts
I may be wrong but, I did not think the TPS was adustable.

If I recall correctly, you adjust the ISC motor by pressing on the plunger til it retracts, then unplug it. The idle should drop to about 450 and may stall. Now adjust the ISC plunger to a .030 gap at the throttle lever and plug it back in. After that you can do the idle learn proceedure or just drive it and it will learn itself.

Not sure about injector pressure.
 

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2003 STS w/BoseNav, 1993 Deville, 1985 Deville
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As for the injectors, I don't know about the mass flow rate, but I measured 40 psi at idle at the Schrader valve on the rail on my 1993 Deville (4.9L). Hope that helps.
 

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1992 Cadillac DeVille 4.9L
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203 Posts
Stocks are 18 Lb/hr. If you're looking for replacements you can get the orange tipped injectors from any 4.6L Crown Victoria. I recently did this, the change was phenomenal. They are 19 LB/hr, and are 4 spray instead of 2-spray. Much more responsive.
 
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