A few weeks ago my wife came home and said she could smell gas after filling up her car. I checked it out and the fuel filler tube was rusted to the point that it started leaking. No big deal, ordered a new one and told her to just keep it below 3/4th of a tank.
Yesterday I replaced it, took about an hour, and everything seemed great. The car had about 5/8th of a tank of gas so I decided to go top it off and make sure there were no leaks. Drove 2 miles to a gas station, filled it up, and no leaks. However, I didn’t even make it out of the lot and the car was mis-firing and the CEL came on.
I babied it home and started thinking about it. I assumed some rust must have made its way into the tank and now it was clogging the filter. Picked up a new filter, replaced that, and pulled the pump and put a new strainer on it. There was a tiny bit of debris on the strainer, but hardly enough to block it. Looking inside the tank through the fuel pump access door with a flashlight I saw no debris in the tank.
Buttoned it back up and it started after a few seconds of cranking to get fuel in the system again. It idled rough for a minute then seemed fine. As soon as I tried to back it out of the garage though the sputter returned. I tried a quick run around the block to see if it would clear but nothing.
I’ve already checked with the gas station and they haven’t received any other reports of bad gas. Even so, I decided to drain the tank. Got about 99% out (everything except what my siphon wouldn’t pick up through the fuel pump access door). Put in 6 gallons of new gas and some dry gas, but still the same problem.
I pulled the plugs and they look pretty worn, so I’m going to slap in a new set right now, but I seriously doubt that’s going to fix it. When I put my ear on top of the tank and have someone turn the key I can hear the pump spin for about 2-3 seconds and it sounds fine.
Anyone have some suggestions what to try next? I’m thinking fuel pressure test but I don’t have a tester. I’d also like to scan the code and see what it was, but I don’t have a code reader either. Anyone have either I could borrow?
Don’t have a scan tool, so I’m not sure. Looking for someone I could borrow one from since I can’t really drive the car to autozone.
In case some of you don’t know me, the wife’s car is a 1996 Geo Prizm.
Something new I noticed. Once it sits for a while, it will start up and idle fine. I can even rev it. But once I try to move it the sputtering starts again. After that happens it continues to sputter every few seconds even idling.
I thought about that, but why when I let it sit for 30 minutes or so can I start it up and it will idle/rev perfectly?
I noticed when I changed the plugs last night that 3 were a nice tan color, but one was black. I’m guessing that’s the cylinder I’m having issues with.
There is probably enough fuel getting through to idle but not to drive. I would pull each injector and have a look. Obviously you are going to want to change plugs too.
Ok, tonight when I get home I’ll pull the injectors. Looks easy enough since the fuel rail is sitting right on top of the engine. Anything I can do to test/clean them at home? I put the new plugs in last night so that’s all set.
since it is 96 and obdII, there may be a gas cap sensor. If this is disconnected, the car will go into limp mode. Check the codes man, don’t pull the injectors off, someone has to have a scanner you can borrow.
I ran home on lunch to take a look. There are no wire/sensors attached to anything from the tank to the gas cap. This is based on both looking at the car and the exploded diagram in the haynes manual.
If I have time tonight I think I’m going to try driving it to autozone to have them read the code. I’ll have the wife follow me in the truck with a tow strap in case I don’t make it. Only problem is I had the negative battery cable off for most of the day yesterday while working on it so now the CEL isn’t on. I’m guessing by the time I sputter and cough my way to autozone it will come back on though.
^ that is true but i doubt that a geo prism has that technology. i know my focus doesnt. i would venture to say its injector related, as jeremy_gt’s mom experienced the same thing in her tuarus and we went through so much crap and replaceing parts and in the end it was one bad injector. 96 tuarus BTW i think
It was a 95 Taurus. And yes I expierenced alot of the same problems you have. It had rough idle and drove with no balls. Not that the taurus had any balls to begin with, but that is beside the point. I was surprised after replacing them that it fixed the problem, but it did. The sputtering and coughing that the engine is making sounds pretty much like what my car was doing. I would deffinetly considering injectors after getting the CEL code.
Last night I took a quick look at it and it was idling fine. I took a quick trip around the block and it only misfired slightly, and the CEL did not come back on.
Tonight I threw in some fuel system cleaner, some more gas, and went for a little longer drive. The problems came back as soon as the car started warming up, CEL came back on, and by the time I got it back to the house it was barely able to stay idling. Saturday I’m towing it to autozone to scan the codes, I’ll post updates after that. I’m really stumped on this one.
Yep. It was identical to the old one, clearly marked with a “to tank” side.
The part that really confuses me is the fact that it runs fine cold. I ran it close to redline when I left the driveway tonight and it didn’t sputter at all. By the end of my street it was stuttering slightly, and by the time I had gone a mile or so it was back to running like crap. I’m starting to wonder if the tank vent isn’t working. Maybe the vent on the new filler tube was plugged?