Ignition sticking

[pajeff02]

Around 2 weeks ago, the ignition key cylinder for our '07 Suburban stuck in the "start" position for just a second. At the time, I was tired and thought maybe I had accidentally held it too long. As I have been driving it fairly regularly lately, it does appear to be an actual issue. It doesn't happen every time, but maybe 1 out of every 3 starts the key cylinder will hang up and I have to manually turn it back to the "run" position. Sometimes the truck will not start when this happens and a second attempt is necessary. For whatever reason, it seems to do it more when it is real hot out.

Anyone have clue on this one? First time I have ever had a vehicle do something like this.

[0rion]

the first thing I would do is try spraying some electrical cleaner around it and then some lubricant. Might just be some crud in there. That would be the cheapest and easiest place to start. After that it may be time to take it apart if that doesn't fix it.....I'm betting it's just crud in there though.

[Firebirdjones]

Probably not the ignition cylinder but more likely the switch down on the column.

Like Orion stated those things down on the column get cruddy and dirty. I've had it happen on the older cars so I would assume your new truck is built the same way. There is a metal rod that slides back and forth inside the column that triggers the switch on the column under the dash.

If cleaning and lubing doesn't cure it then it might be time for a new switch under there. Just cheap plastic things. Another issue I've had with them is having to turn the key really far before it actually triggers the starter. Almost like it's out of adjustment, but the switch just gets worn to the point, eventually it won't trigger at all. You might have to drop the column to access it depending on how big you are

[pajeff02]

I can tear into it some evening and see what it looks like. Hopefully a little TLC and lube will do the trick. I have rebuilt a couple of columns, but all in older stuff so no airbag or electronics to speak of. I was concerned that it might be an issue with these trucks and thought it best to ask. Thanks guys!

[Smittro]

Many GM ignitions used a "rack and pinion" type setup..

Could be if your's is this type that there is something going on where the rack and pinion come together.

This is/was typically found on the left side of the column strait across from the key cylinder under the column trim sleeve.

Could be a return spring issue as well as all the afore mentioned issue depending on what you actually have there.

I also agree start simple no change and you may have to dig into it more..

Just my ,02

[silverWS6]

My truck does around the same thing, what kind of lube and cleaner are you gonna use Jeff? Just spray it in there?

[pajeff02]

Not sure exactly. Will need to open it up and see what I find.

[04yellowjacket]

take the key and spray wd-40 on it and insert it. then reapply this step about 4 or 5 times. my gto was doing the same thing and all is good on it after that treatment.

[pajeff02]

With the departure of hot weather, the issue has resolved itself. A little WD-40 certainly can't hurt though. Thanks!

[az gt eater]

All the problems I have had with work truck keys over the years has been caused by the key being worn out. Grab a fresh key, and everything is perfect.

[silverWS6]

I just tried the WD40 trick on my truck and no dice, looked at ignition cilinder with the keys and they run about $50. Would I have to get the keys reprogrammed or would it be a direct replacement of the ignition lock and different keys?

If I were to try the just a new key route like azgteater, would I have to get the key at a dealer? The key is a bit worn out now

[pajeff02]

I know I took both sets of keys to Michigan and am almost certain it acted the same way with either key. I'll take a look at them to see if there is any discernible difference in wear.

[az gt eater]

I just tried the WD40 trick on my truck and no dice, looked at ignition cilinder with the keys and they run about $50. Would I have to get the keys reprogrammed or would it be a direct replacement of the ignition lock and different keys?

If I were to try the just a new key route like azgteater, would I have to get the key at a dealer? The key is a bit worn out now

A good locksmith would be able to set you up. I would trust him more than the dealership in this case. He understands the resistance values, and would be able to use your old key to make a sharper new one.

[pajeff02]

Well... back to the same issue. It appears that the ignition in our truck is similar to a push button start. Once the key is turned, even if you manually turn it back the ignition will continue to try to start the vehicle for just a few seconds more. Our truck will now complete a full cranking cycle, stop, and then start almost immediately on the second try. Engine runs fine -- I just pulled my trailer today with it so no lean issues, and no check engine light. I am almost thinking that the fuel in the rail is vapor locking, or leaking down past a bad injector. I am going to slap a pressure gauge on it when I change plugs and wires this week. I will also clean the throttle body and give everything there a once over. Thoughts?

[Firebirdjones]

With the fuel pressure these fuel injection engines have, it's extremely difficult to vapor lock one.

I'd bet you are on the right track wanting to check the fuel pressure. I'm guessing you might have a weak pump. Wifes camaro was acting similar to what you describe with the stock pump (10 years old). It was only 2-3 lbs. lower than spec at idle when I checked it, but once in a while it wouldn't start on the first crank. I installed a new 255 pump and it's fired off on the first hit ever since with rock solid fuel pressure. Good preventive maintanance anyway knowing it's good for a few more years.

[pajeff02]

I kind of figured I'll end up dropping the tank... oh well, gives me something to do.

[Firebirdjones]

I knew that would lift your spirits, I'm here for ya Jeff

[pajeff02]

Be better if you were here in PA... say around 5:30 tomorrow evening so we can get this job done and over with.

[Firebirdjones]

[0rion]

What a shame.....I'm in PA but will be back in Ohio & at swimming lessons for the kids by 5:30. Almost had some free help.