'99 Yukon stalls & cuts out intermittently

[DaveEye]

I've searched the forum and found some similar issues, but figured I'd post with the exact problem. I just bought a '99 Yukon a week ago and it was running fine. Passed smog inspection with no problem so I'm assuming the catalytic converter is okay.

Anyway, what is happening now is that regardless of the outside temperature, the Yukon starts fine in the driveway and drives well. Once I stop somewhere and shut off the ignition, if I go back to start it a few minutes later, it starts and then dies. I'll get it to start and run, but then when I put it in gear it dies. All the instrumentation lamps cutout and the power to the clock on the stereo cuts out as well. It's like something electrical is cutting out, which in turn cuts off the fuel and the engine dies.

Once I get through this episode though it seems to run fine again. I've seen responses like distrbutor cap & rotor, dirty MAF, :hlp:cam position sensor in distributor cap, crank position sensor behind the starter, etc. Would any of these be intermittent in such a way that they *always* happen after the truck has been running well and gets shut off? Would any be associated with the electrical system shutting down, only to work fine a few minutes later?

Thanks in advance for your help!

 

[bsamoul]

When my crank position sensor was going, it would only happen after I drove it and over a couple weeks it happened every time i started whether it was cold or hot. But, I think your's is electrical. Everything tight around your battery, no loose cables lying around anywhere?

 

[DaveEye]

But, I think your's is electrical. Everything tight around your battery, no loose cables lying around anywhere?

Yes, the cables are looking good and no corrosion on battery terminals. The Yukon hasn't had the problem at all today, but late this afternoon I cleaned the MAF in hopes that this may be the problem.

 

[treepete]

sounds electrical.

Check around the engine bay for harnesses or cables that are loose. If you have a wire that rubs through and shorts on the chassis or body etc. that may cause electrical problems.
has any work been done to it lately that you can remember, or the first time it has happened been recently?

If your losing the clock every time, its electrical in nature.

cleaning the MAF. good call. even if thats not the problem, its a good thing to do.

and welcome to the forum.

Pete

 

[DaveEye]

sounds electrical. Check around the engine bay for harnesses or cables that are loose. If you have a wire that rubs through and shorts on the chassis or body etc. that may cause electrical problems.
has any work been done to it lately that you can remember, or the first time it has happened been recently?

Thank you Pete! I just got the Yukon for my wife about a week ago, so I have no idea what the history of it is. As I mentioned in the original post, it was driving fine and just started doing this a few days ago.

I understand that it is most-likely electrical in nature, but what would explain that it does this only after starting and driving fine? Bsamoul said there were similar circumstances when it was a crank position sensor going bad, but that my situation is probably something else.

I'll see what I can find as far as loose wires or shorting, but that may take more patience than I have. I'm tempted to just take it in somewhere to be diagnosed, but with it being an intermittent problem and with no check engine light glowing it may be a waste of money.

 

[DaveEye]

UPDATE: Well, after going almost 2 days without the problem, it happened again tonight. After driving fine all afternoon, it was hard to start and kept stalling when I went to leave. It stalled a couple of times when I put it in gear, but then drove fine to the grocery store. Started up and drove fine after I finished shopping about 15 minutes later.

The electrical system didn't cut out this time. So, I'm thinking it sounds like the cam sensor or crank sensor. Is there any way to diagnose this issue or is it something where it just needs to replaced to see if it solves the problem?

 

[DaveEye]

I just changed the crankshaft position sensor and it started and ran fine, but I'll have to wait a week or so to see if this fixed the problem. Also, the sensor is in the front of the engine and relatively easy to access and replace. It takes an 8mm socket and that's it.

At this point with it starting fine I don't think it needs to re-learn any codes, but I did see that the Haynes manual states it does need to be done.

 

[JP422]

Hello DaveEye...

Any more updates? Has everything been ok so far? How much did the crank sensor cost you, and did you ever get it 'relearned'?

I've had the experience too... but very rarely.. and months before it happens again. Once it cut out like the battery was barely connected... almost no electrical power... but all looked fine. After several minutes, it started up fine, and no prob for a many months.

The last time it wouldnt' start was a rainy day after driving perfectly fine that morning. I stopped to put air in my spare tire (just had a tire blowout). then when I got back in to go home.. it would crank, but no fire. Starter sounded healthy. Battery sounded strong... but nada. After a few minutes went by... i tried checking all my wires, etc... The last thing I did was wiggle the wire harness around the ignition ignitor... When I cranked again, she fired up perfect, like nothing was wrong... and it's been a few months of perfect driving since then. I still don't know exactly what it is... but I hope it gets solved. This hasn't plagued me bad yet, but I just don't want to worry about it.

 

[DaveEye]

Hello DaveEye...

Any more updates? Has everything been ok so far? How much did the crank sensor cost you, and did you ever get it 'relearned'?

I almost hate to say anything as it's been less than 2 weeks (as it was an intermittent problem, it could recur if this wasn't the fix), but so far no more problem.

Other posts in this forum stated that if the tachometer isn't showing the engine turning over while starting, then it's the crankshaft position sensor. However, I had times when the tach was moving and everything else was exactly the same.

For me, the hardest part of replacing the crankshaft position sensor was pulling out the rubber tab from the mounting piece that holds some wires in place. The sensor itself was incredibly easy to change...it's just one bolt and one wire connector. Nothing had to be re-learned.

I buy my parts at RockAuto.com as they are usually cheap and they have great service. The crankshaft position sensor was $38.79 + shipping.