Engine does not idle when cold?

Hi,

This could be a few things such as an EGR issue, an EFE valve, fuel mixture/pressure, and so on. Here is what I need you to do. We need to determine if there are diagnostic trouble codes stored in the computer.

This vehicle has an OBD1 system that doesn't require a scanner to retrieve codes. All you will need is a short jumper wire or even a paper clip.

Follow the directions in this link and let me know the results:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Take care,

Joe

I got codes 13, 22 and 43.

Hi,

The codes show a few different things. The two that have the most interest to me are the 13 and 22. This vehicle should have a throttle body injection, correct? If it does, the first thing to focus on is code 13. This indicates an open circuit with the oxygen sensor. Check to make sure nothing is damaged, the wiring is in good condition, and nothing has melted due to heat. If everything looks good, test the sensor.

Here is a link that explains how to check one:

https://www.2carpros.com/articles/how-to-test-an-oxygen-sensor-02-sensor

Also, I attached the descriptions below for each of the codes, so you have a reference.

Let me know what you find or if you have other questions.

Take care,

Joe

See pic below.

Okay. So, I checked the wires to the TPS, and the 02 sensor and they all looked good and seemed to be working. So, I replaced both sensors and the truck will idle a little better but still smells rich and will shut off if you don't give it throttle for the first couple minutes after starting. And when you start driving it is a little sluggish for a few minutes then it's okay. I no longer have any codes when I check.

Hi,

Have you checked your fuel pressure to make sure it isn't too high? Also, is the coolant temperature sensor working properly?

Here is a link that explains in general how to test fuel pressure:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let me know. Also, let me know if you notice any dark gray smoke from the exhaust.

Take care,

Joe

I have not checked the fuel pressure. But I have replaced both of the coolant temperature sensors. Sometimes when you start it and it smells real rich I do see a little bit of black/gray smoke but it clears pretty fast.

Hi,

I would confirm the fuel pressure isn't too high. That would cause the rich smell and the smoke you are seeing.

Let me know.

Joe