Tbi Issue Idle In Between Cold/Hot

[Gearheadmike]

History/info dump. 1988 c3500 350 th400 87k miles. Ex air force base truck. I deleted the air pump and egr. Has short style headers. New aftermarket distributor. New intake gaskets. Tbi gasket. New fuel pump and filter. New air idle control valve. New plugs and wires. It had the hot fuel pump module under glove box but it is unplugged and gone tho pump still runs a few seconds after key is shut off.

Now.. the truck starts and runs good cold but seems when warming up the idle fluctuates up and down it had a code pop up over the winter when i moved it for 02 sensor so i replaced that with a new a/c or delfi one can't remember. It doesn't trip a cel light but i do have a old school scan tool i can plug in and see live data. Just don't know what i'm looking at haha. I just don't want to keep throwing sensors at it and still have issue. About to put carb and hei dist and call it a day with the tbi but do kind of like the injection.

You must be registered for see images attach

 

[sntrym]

Did you have the EGR and AIR pump tuned out of the ECM when you removed them?

 

[Schurkey]

1988 c3500 350 th400

I deleted the air pump and egr.

Probably mistakes.

It had the hot fuel pump module under glove box but it is unplugged and gone tho pump still runs a few seconds after key is shut off.

Why disconnect the hot fuel module?

Having the pump running after the engine shuts off seems...unusual.

the truck starts and runs good cold but seems when warming up the idle fluctuates up and down

Verify coolant temp sensor, and TPS. Check IAC valve operation.

Did you ever dick with the base idle screw?

Does this 454 have an idle speed compensator? Some--maybe all of 'em in the TBI era did. Does it work properly?

it had a code pop up

WHICH "code"?

when i moved it

"It" what?

for 02 sensor so i replaced that with a new a/c or delfi one can't remember.

So the O2 sensor is new?

About to put carb and hei dist and call it a day with the tbi but do kind of like the injection.

Carb and distributor would be a big mistake.

You must be registered for see images attach

TWO breathers? Why is the PCV system screwed-up?

 

[Gearheadmike]

Did you have the EGR and AIR pump tuned out of the ECM when you removed them?

No as none around me know's how to mess with the ecm's