4.0 sohc wants to die when I hit the gas

[JOLENE_THE_RANGER]

I have a 4.0 sohc
When the engine is cold it’ll start and idle fine but as soon as I touch the gas pedal it’ll almost shut off. Release gas pedal and the rpm’s pick back up quickly. This problem goes away completely when the engine is warm
Also some times, cold or warm when coming to a stop the engine will die unless I feather the throttle
just replaced plugs with motor craft plugs gapped correctly. Also cleaned iac. Haven’t touched anything else.
any ideas?
Tia

 

[Roert42]

Sounds definitely sensor related. Figure either MAF or upstream O2 sensor.

Any codes? Surprised if there wasn’t

 

[JOLENE_THE_RANGER]

Buying a MAF today to try out. I will report back.

 

[Uncle Gump]

I kinda doubt o2 sensors... just because it's cold when it happens and still in open loop.

Have you looked at live data with a scan tool? This is obd2 right?

 

[CamTheHedgehog]

I kinda doubt o2 sensors... just because it's cold when it happens and still in open loop.

Have you looked at live data with a scan tool? This is obd2 right?

It should be unless it is a swap, the 4.0 SOHC began production in 1997, in 1996 OBDII was mandated.

 

[Uncle Gump]

It should be unless it is a swap, the 4.0 SOHC began production in 1997, in 1996 OBDII was mandated.

It's a swap for sure... I didn't remember the details though.

 

[JOLENE_THE_RANGER]

Yeah it’s a swap. Runnin on eec-iv
Been running fine the last 2-3 years. This problem just came up.

 

[CamTheHedgehog]

Then disregard everything I said, and I wish you well in troubleshooting. Like uncle Gump said, the computer is most likely getting faulty data from somewhere, and is giving too much or not enough fuel when you try to give it throttle.

 

[JOLENE_THE_RANGER]

New maf made no change
Ran a KOER test and got code 116
Took a peek at the coolant sensor and noticed it looking weird.
took it out and viola. The contacts probably weren’t engaged.
got a new one coming tomorrow, fingers crossed.
sometimes I wish I would have switched to obd2 when I did the swap. Haha

 

[Uncle Gump]

Makes sense... hopefully you're good now.

Maybe start looking at a stand alone system... and a laptop?

Just thinking out loud I suppose...