Super low idle

[denverkenyon99]

I have a 1990 K1500 with the TBI 350. I keep having a random issue come up with the idle. Basically, truck runs fine, and sometimes when I go to start it, it fires once or twice, and then dies. I hold the gas slightly to start it and it starts up fine, but I have to let off slowly in order for the engine to keep running. It idles at about 250 rpm when I do this.

I keep finding that the IAC pintle is almost all the way out. I twist the pintle back in and it runs fine, and basically repeats this entire process after about 2 weeks. There is no engine light, or a flash code regarding the idle speed.

I do need to replace the connector, as the clip and the wire cage are both broken, however, it never comes unplugged entirely. Do y’all think this issue is directly related to the connector, like maybe it keeps losing connection?

 

[tayto]

you can buy a new connector and unpin your current one so no splicing required. i would start by checking fuel pressure and base timing. you shouldn't have to touch the pedal to start at all

 

[denverkenyon99]

you can buy a new connector and unpin your current one so no splicing required. i would start by checking fuel pressure and base timing. you shouldn't have to touch the pedal to start at all

Thanks. The reason I have to touch the pedal is because the IAC keeps closing, so the engine isn’t getting enough air at idle

 

[tayto]

has the tamper plug been removed from the base idle adjustment on the throttle body?

 

[denverkenyon99]

has the tamper plug been removed from the base idle adjustment on the throttle body?

No, that’s one of the first things I checked. It was idling fine when I first posted, and after I shut it off, it did the same thing again.

 

[Schurkey]

1990 K1500 with the TBI 350.

It idles at about 250 rpm when I do this.

I keep finding that the IAC pintle is almost all the way out. I twist the pintle back in and it runs fine, and basically repeats this entire process after about 2 weeks. There is no engine light, or a flash code regarding the idle speed.

I do need to replace the connector, as the clip and the wire cage are both broken,

You have IAC issues, and an IAC connector problem.

Yes, you have to fix the connector.

Do that, see what happens.

 

[denverkenyon99]

You have IAC issues, and an IAC connector problem.

Yes, you have to fix the connector.

Do that, see what happens.

Seems to be working. I replaced the iac as well. I’ll let y’all know if anything else happens.