Someone stole gas from me and now my engine runs weird?

[EvergreenZ71]

I think it's all been over thought, he said he already on his 2nd tank of e85, I'd say IF anything was poured in it'll be long gone by now.

X2 but to be safe I’ll ask if the tank was drained to near empty prior to either of those two fill ups.

Along the lines of the paranoia suggestion; have you tried it again with the gas you were using before?Has it improved / returned to normal, worsened or stayed the same since those two tanks?

 

[Dustin Jackson]

@EvergreenZ71 My Tahoe was basically out of gas when I found the gas cap on my tire. Also I remote started my Tahoe that morning so the Tahoe was already running when I found the gas cap on my tire.

I put the gas cap back on the Tahoe and drove it about 10 miles to work, and then on my way home the gas light came on and I stopped by my usual gas station and filled up with 91. Since then I've filled up 2 more times at the same spot with 91.

There are times the engine runs smooth and other times it runs with a little miss or something so I'm not too worried about it. Weather temps shot up over 100 the last few weeks and I am just attributing it to the higher temps.

My AC blower resister has been overheating and my head unit has also been overheating so a little stumble in idle is to be expected...I hope

If something was put in my tank, there was only a few gallons of gas in there and I drove it about 20 miles without catastrophe

 

[j91z28d1]

running them without a cap because it's a pressurized system. usually sets a code. I wonder if that has something to do with it only it didn't set a code because of auto start.


do you have a higher level scanner? might be interesting to clear out the drive data stuff and see what it doesn't.

 

[EddieC]

it has been a very long time but I once fueled up and didn't get more than a mile or so and the car flamed out.
I managed to get it near home and to a trusted repair shop; the gas had water in it.
The tank was drained and replacement gas cured it.
I imagine we never know what is settled in the bottom of the station's tanks.
Just a thought to try different gas. Seafoam has saved my butt many times with old gas though so that might be worth a shot first.
It was my girl friend's Camaro and she was not to happy having let me use it.

 

[Dustin Jackson]

@j91z28d1 That's an interesting thought, I guess it wouldn't be able to tell that the cap was missing until it was started? I guess I can pull the gas cap off and try to start it and see if it pops a check engine light like it should.

I only have a bluetooth OBD2 reader with an android phone running torque pro something like that. I also have an autocalv3 that has some monitoring functionality I think

 

[j91z28d1]

@j91z28d1 That's an interesting thought, I guess it wouldn't be able to tell that the cap was missing until it was started? I guess I can pull the gas cap off and try to start it and see if it pops a check engine light like it should.

I only have a bluetooth OBD2 reader with an android phone running torque pro something like that. I also have an autocalv3 that has some monitoring functionality I think

I'm not sure what you'd have to clear, but my torque app does show the catalytic drive stuff. not sure what most of it means, something about drive cycle.

on some ford's we used to have at work you could clear all the learned volatile memory by key on not running and hit the throttle 0 to 100 3 times within a few sec. I don't remember what that was called, clearing Kan or sometimes like that, but anyways gm should have some way to clear all its learned stuff, like the long term fuel trims and stuff and start over.

maybe clear codes on the scanner and then do the pull the battery cables wait a while and then touch them together for a bit? unless someone where knows a short cut to clear all that out?

just a thought. might no nothing.

 

[ZKWBQD]

Hello gentlemen, in the middle of the night on the 4th of July someone stole gas from my Tahoe while it was parked in my driveway. I went to leave for work the next day and discovered my gas cap on my rear tire.

I put the gas cap back on the Tahoe and drove to work. On my way home from work I filled up with 91 at my usual gas station, but ever since then the motor has idled a little rough and on the freeway my Tahoe has a little shimmy like an unbalanced tire or slight misfire.

I just redid my front brakes the day before my gas was stolen so I am going pull my front tires back off and inspect all mating surfaces but I have this paranoid/OCD feeling in the back of my mind that the stealing of the gas caused something to happen with either the EVAP system or they got dirt in my tank. OR the gas station just switched to summer fuel here in California. Either way my motor isn't running as smoothly as it did a few weeks ago.

Today I filled up another tank of gas and the Tahoe had a very notable rough idle immediately after starting it from filling it with gas.

Along with having my property violated! My Tahoe isn't running as well as it used to and I want to see if there is anything I can check on, I am hoping these are just the early stages of a EVAP failure. I have had a history of not being able to fill up the gas tank in one go, the pump always clicks so I have to hold the nozzle at a special angle to get to a full tank.

Lesson learned, locking my Tahoe every night and installing security camera.

Anything you guys can think of or am I just paranoid?

This is how I found my tahoe:
View attachment 404195

First, I have tried to siphon gas out of my own vehicle to use in a lawnmower, and I discovered it is blocked even using a very small hose. I'm wondering how they got to your gasoline. Second, remember, security cameras do NOT prevent crime, they only document crime. Unless the crime is very serious, or you know the perpetrator, the police will have no interest in your video.

 

[Dustin Jackson]

@ZKWBQD I think at this point the consensus is that they weren't able to get anything out of the gas tank, most likely a failed attempt. The fuel level was low on my accord

As for home security I agree a camera isn't as good as a locked gate but I feel that a driveway security camera mounted on the side of my house in plain view and a motion activated flood light are great deterrents.

BTW BlueIris and some RSTP cameras work great, the blueiris software works very well. I set it up to email me a screenshot of any motion in my driveway, which luckily so far has just been screenshots of my cats coming and going.

 

[Bill Barnes]

The only difference I can think of in the caps would be the color and the gasket material. The black cap might have a gasket that is not resistive to the E85, and might decay over time. But that's just conjecture on my part and if the gasket on yours is in good shape now, running E85 in the short term shouldn't cause any problems. Long term you may want to get the yellow cap for it, or run with the black cap and see what happens. The only job that cap has is to seal that filler neck.

If they put something in the tank it's not going to affect the evap system, at least not right away. It would be more fuel contamination than anything. But not knowing if they did add something, it's hard to tell if that's the case.

If your VAN'S 8th character is a "Z", you have a Flex Fuel/E85 vehicle. I have had two, a 2001 5.3 Suburban and a 2005 Yukon XL 5.3. Both had black Fuel caps from new. The Yukon now has 237K miles, and did have evap vent and solenoid problems, which set a CEL, and caused Fuel filling problems, but I never had a rough idle or running issues. I replaced the vent valve and the solenoid, which resolved the problems.

 

[Geotrash]

If your VAN'S 8th character is a "Z", you have a Flex Fuel/E85 vehicle. I have had two, a 2001 5.3 Suburban and a 2005 Yukon XL 5.3. Both had black Fuel caps from new. The Yukon now has 237K miles, and did have evap vent and solenoid problems, which set a CEL, and caused Fuel filling problems, but I never had a rough idle or running issues. I replaced the vent valve and the solenoid, which resolved the problems.

But not the charcoal canister? If not, you're on borrowed time at this point. Well worth the $150 and 20 minutes to replace it before it releases its pellets and ruins your week.