Renix starts HARD and LONG after adjusting idle screw :(

[knever3]

I have had so much trouble with this, full backstory.

 

4.7L stroker, 99 intake, BBK throttle body, Hesco TPS adapter

 

It has struggled to idle at a constant speed, hunting up and down RPM from 300-800 RPM, can't confirm unless I hook up my MT2500, just gauge reading.

 

It seems to be worse in the winter months, I use remote start and let it idle for 20-25 minutes to warm up for a 6 minute drive LOL

I was tired of it so I turned the allen screw to increase the RPM at idle and it doesn't surge that I notice anymore.  Now the idle is too high, about 1k and I don't like it.  Turned it back down and it takes 10 seconds to start, like it is not firing the ignition and you need to pedal it to get it to start like a carb.

 

I want to set the idle screw correctly and remove/clean the IAC again.  I've replaced it years ago, but never solved the problem.  I have worked with grounds everywhere, measured the TPS voltage several times.  I have not checked the AC voltage for the CPS yet.  

 

Where do I go from here?  I always thought it was temperature related, but who knows.

[Eagle_SX4]

23 minutes ago, knever3 said:

I want to set the idle screw correctly and remove/clean the IAC again.

My understanding is that screw is not an idle adjustment screw. It is a throttle blade stop screw. It should be adjusted until the throttle blade is fully closed but not scratching the walls of the throttle body. The IAC is what controls the idle speed. 

 

 

[knever3]

Had 5 minutes, re-adjusted throttle plate stop to just rest on the screw.  Hooked up fuel pressure gauge and cycled the ignition several times.  No fuel pressure, check valve on pump bad.  When it did run my reading was 23psi, should be 45 and it did not go up when throttle applied.  Bummer, this pump lasted 15 years.

[Eagle_SX4]

10 minutes ago, knever3 said:

Had 5 minutes, re-adjusted throttle plate stop to just rest on the screw.  Hooked up fuel pressure gauge and cycled the ignition several times.  No fuel pressure, check valve on pump bad.  When it did run my reading was 23psi, should be 45 and it did not go up when throttle applied.  Bummer, this pump lasted 15 years.

I don't think your fuel pump is dead. That gauge is reading 28 psi not 23. Cycling the ignition will get the pump to come on only after sitting for a few minutes.

 

Fuel pressure should be checked with the engine running. 31 psi with the vacuum hooked up to the fuel pressure regulator and 39 with the vacuum line removed.

 

 

[knever3]

I cycled the ignition listening for the relay to click.  The gauge never moves until I cranked, then it would immediatly drop back to zero.