Hi all,

Recently I've had hard starts from the jeep after it's been sitting a good while. I have feathered the gas before and got it started. Tonight I tried three times without being able to start, until I floored the pedal and feathered letting off until it sounded began starting, which it did.
The jeep cranked strong, it's pretty cold and the battery gauge went halfway between 9 and 12 but was cranking strong I really don't believe this to be the issue.
.Battery was tested goid 2 months ago
.Injectors were brand new BWD 4 hole installed 4 yrs ago
.Fuel pump is a Bosch installed around the same time
This is a week in to having this issue. I need to retest the battery just to be sure( through it did not get welder cranking)
. I need to test the fuel rail pressure before starting

If one injector is leaking how doin find It?
Can valves cause this starting issue?

What should I be trying so I can narrow this down

 

When an XJ won't start without feathering the throttle that is often a sign that the Idle Air Controller (IAC) is not doing its job. it is the small controller on the throttle body that is responsible for letting air into the intake during startup when the pedal is not being pressed as well as maintaining the target engine RPM decided by the computer.

Pressing the pedal all the way to the floor will put the computer into "clear flood" mode and will allow cranking and spark, but will disable fuel injector pulses. If the IAC has failed to open an allow enough air for combustion, then yes, it is possible that things were flooded and that cranking in "clear flood" mode, followed by manual feathering of the throttle allowed air and got things started.

In short, if feathering the throttle produces a successful start, that is a strong sign that the IAC is not opening as it should during the startup sequence.

I think your next step should be to remove and clean your throttle body, including the IAC, and replace the IAC if its condition is suspect even after gentle cleaning. Sometimes they get covered with the carbon/tar over time and can become quite sticky and resist movement, especially when cold.

 

how much is the IAC?

 

Approx $35 (after market like Standard Motor Products) to $65 (OEM Mopar)

 

Not a lot involved in cleaning the t/b and IAC yourself.
http://cruiser54.com/?p=60

Found this test for it in some notes. I know it worked on my '96 in 2014.
IAC contacts:
A
B
C
D

A to D =40-80 ohms
B to C =40-80 ohms
B to A = open
C to D = open

Mine tested border line but it worked. I eventually replaced it a year later with one from SMP.