hard to start/stalling

Mean Green XL · June 25, 2004

Hi All,

This is my first post at GM-trucks.

I recently purchased an 02 Yukon XL2500, 8.1 for my wife.

It has 57,000 miles on it.

I have already changed the fuel filter.

Problem:

When the vehicle is already warm it can be hard to start. It will turn over, but not fire off. Igf the key is turned off, it will usually start.

Today, my wife had the truck stall out while driving a steady 45 mph.

The red battery light came on in the message center ( I guess meaning it had stopped running), and then the truck started to run again without incident.

Key was always in the run position, it just came back to life, she said.

No SES light or code to refer to.

A Mechanic friend thinks the fuel pump may be the culprit.

However, After talking to a tech at the dealership, he said if it was a 5.3, then definately a fuel issue. He also said they see crank sensors and cam sensors go out in the 8.1 engine frequently.

How can I find the real problem, without taking one for the team?

Who has the best service manual out?

Helm's I assume is a factory type manual. It is worth the cash?

Sorry for the long post, and starting off with problems.

BTW, The wife named our truck "Mean Green" because of her green color and the 496 cu in of fury/gas sucking pig

Sincerely, Jim

dukbludvl · June 25, 2004

I had these exact same symptoms with my 2000 Yukon in early 2003 when it hit 45K-50K miles. More than likely, it is that your throttle body is full of gunk making the butterfly valve stick... when this happened to me, it caused my truck to stall out (at lights or whatever when I was stopped, not when I was on the accelerator, really).

The first thing I would check -- since it's an easy $3 fix -- is whether you need to clean your throttle body. If you do, get a can of throttle body cleaner at your local auto parts store, spray some on a clean rag, and then get in there and wipe off the carbon build-up -- especially around the butterfly valve.

This worked like a charm for me. She idles real smooth now. I did it once again (although, I didn't have the symptoms) a few months ago just to keep it clean.

Let me know if you have any questions about this and whether it works. If this isn't it, I'm sorry I couldn't be of more help.

Jon