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View Full Version : Strange behavior - bad fuel?


jw
12-23-2002, 09:56 PM
Tonight while I was running errands, I went to fill up my tank just after the yellow light came on. I filled it up w/ 93 octane at a Mobil. After putting the car into D and going about 20 feet, the car stalled. The service engine soon light came on and I tried to restart my car. By accident, I had the car in N and it would only crank, but wouldn't turn over. Finally I put the car into P and started the car.

Regardless of being in SD, D, or 1, the car seemed to be bogged down and didn't have the usual pep. In addition, it didn't feel like it was downshifting properly regardless of whether it was in D or SD. After driving a few miles, I decided to pull over, put the car into P and turn off the engine. Then the car seemed to run fine for another mile or so (it had the usual SD or 1 pep from a stop). However, after another mile or so, I noticed the problem again.

After letting the car sit for 10-15 minutes once I got home, I took the car out for a drive and everything seemed fine. So far, so good.

Could it have been bad fuel? The tank is now full. Would the rest of it be bad as well? Any reccommendations?

Pinecone
12-24-2002, 05:31 AM
Could be you have a little water in the tank., Filling it stired it up.

Get a bottle of RedLine Water Remover and Antifreeze and add 2 - 3 ounces each time you fill up the next couple of times.

Add it to the tank just before you fill up to mix it with the gasoline.

jw
12-24-2002, 06:28 AM
Originally posted by Pinecone
Could be you have a little water in the tank., Filling it stired it up.

Get a bottle of RedLine Water Remover and Antifreeze and add 2 - 3 ounces each time you fill up the next couple of times.

Add it to the tank just before you fill up to mix it with the gasoline.

If it's not water in the tank, will the RedLine Water Remover cause any adverse consequences?

ff
12-24-2002, 06:58 AM
Originally posted by jw
If it's not water in the tank, will the RedLine Water Remover cause any adverse consequences?

I seriously doubt it's water in the tank. If you were low on gas, you would've noticed the erratic running before refilling the tank.

The problem you describe sounds a lot like vapor lock, where you run an engine hot, turn it off for a short time, then start it again. It will often stall and run rough for a short distance. If the problem persists, there could be something else wrong, and the computer should be throwing some codes. The dealer will be able to check that out.

jw
12-24-2002, 07:07 AM
Originally posted by ff
I seriously doubt it's water in the tank. If you were low on gas, you would've noticed the erratic running before refilling the tank.

The problem you describe sounds a lot like vapor lock, where you run an engine hot, turn it off for a short time, then start it again. It will often stall and run rough for a short distance. If the problem persists, there could be something else wrong, and the computer should be throwing some codes. The dealer will be able to check that out.

Didn't even think about that. Haven't had a car w/ vapor lock problem in many years. I used to see people pulled over on 70-W headed from Denver to the mountains with the problem all the time.

ff
12-24-2002, 07:30 AM
Originally posted by jw
Didn't even think about that. Haven't had a car w/ vapor lock problem in many years. I used to see people pulled over on 70-W headed from Denver to the mountains with the problem all the time.

The only time I've experienced it personally, is in the 2000 Accord V6 I used to own. They redesigned the fuel rail for that year, and as soon as spring hit, and gas stations switched back to the non-"oxygenated" fuel, owners starting having problems with vapor lock. Fortunately, they had an improved part available within a very short amount of time.

ERK
12-24-2002, 09:34 AM
Same thing happened to me about a year ago. After a three hour drive I stopped to fill up. When I restarted the car it had the bogged down symptoms and the check engine light came on. I limped home and when I restarted the car in the a.m. all was well. Vapor lock is probably the answer. :dunno:

The HACK
12-24-2002, 09:49 AM
How much reserves was left? Was it right after the yellow light has come on or did you manage to squeeze every drop out of that tank?

Also, was the previous tank a 91 Octane or a 93 as well? When was the last fill-up?

jw
12-24-2002, 10:34 AM
Originally posted by The HACK
How much reserves was left? Was it right after the yellow light has come on or did you manage to squeeze every drop out of that tank?

Also, was the previous tank a 91 Octane or a 93 as well? When was the last fill-up?

The yellow light just came on. And I believe it was filled w/ 93 on the last tank.

I think it was vapor lock. Runs like a champ today.

Pinecone
12-24-2002, 07:12 PM
That could be it. Auto fuel is fomulated with higher vapor pressure in the winter for better atomization.

But the reason water could do a similar thing is that putting gas in stirs things up more than the normal moving around. Most tanks have a sump to catch water and keep it from causing trouble. Unless you are driving very hard, the water stays in the sump. But the fuel rushing in can mix it into the fuel (not dissolve it, but mix bubbles of water).

In aircraft you have sump drains to remove any water. And you do so before every flight. But when you fill the tank, you have to wait a while to check for water, because the water will no longer be in the sump.

Red Line Water Remover will do nothing to harm the engine. In fact in the M Roadster we add about 1 ounce to every fill up to prevent problems. The Roadster doesn't get driven as much as the other vehicles.

Kaz
12-24-2002, 07:24 PM
I agree, it could be vapor lock. But with the way today's cars have practically air-tight fuel systems to meet environmental 'evaporative emission' standards, if something like this ever happens again, I'd have the fuel system checked out to make sure there isn't a leaky connection, a cracked hose, loose clamp or something somewhere in the fuel system. Also, something like this triggers the MIL per OBD-II specs and should also store a code so having codes read out might be a good idea.

I doubt its specifically a consequence of running it low enough to trigger the light, since I do that every single time before I fill up (in fact just a few mins ago).

jw
12-24-2002, 07:29 PM
Originally posted by Kaz
I agree, it could be vapor lock. But with the way today's cars have practically air-tight fuel systems to meet environmental 'evaporative emission' standards, if something like this ever happens again, I'd have the fuel system checked out to make sure there isn't a leaky connection, a cracked hose, loose clamp or something somewhere in the fuel system. Also, something like this triggers the MIL per OBD-II specs and should also store a code so having codes read out might be a good idea.

I doubt its specifically a consequence of running it low enough to trigger the light, since I do that every single time before I fill up (in fact just a few mins ago).

I've got to take the car in for the sticky pedal fix soon. The part is in and they're waiting for me to bring it in. I'll have 'em do read the codes while it's there. Thx

jw
01-15-2003, 03:15 PM
Turns out it wasn't vapor lock or moisture in the gas line, but a bad cam sensor had to be replaced. At least that's what the service manager told me today. Going to pick up the BMW now.

Rental was kinda ok... a Grand Prix.

AF
01-15-2003, 06:59 PM
good to hear they solved the problem . . .