05 Cobalt fuel problem

[56pontiac]

Originally Posted by rodeo02

Whoa dude you've got ALL kinds of stuff going on. So the 'coon thing happened when the car was basically new? That sucks. FWIW, none of them have any protection up/around the radiator anymore. Overheating in an all aluminum engine is major bad news, but if it happened 3yrs ago and a dab-o-goo has held you off since then, I'd think you're good to go. The only odd-ball 'chewed wire' concern I'd heard of in regards to a delta chassis was with the vehicle speed sensor. It got munched, basically the car wont shift, dash no workie, a mess. If you've pulled the battery a bunch of times and the car hasn't run since, I'm not sure if you'd get a good code read now anyway. I'd still try anyway. I know the ~$40 OBDII with CAN from ChinaFreightTools works like a champ (Harbor Freight Tools).

Joel

When I saw all the damage the coon did that really made me mad. I know a lot of others don't have any protection there either. I should have known when I first got it, to get rid of i. I had assumed it was a rehased Cavalier. Then find out it was actually a new car. Opel Chevy mix.But yet a new car. I had the luck of getting the one that had the radio that kept going into lock, brake light would come on going around a bend and a lot of trim issues. Took it back for warranty work.Said they couldn't duplicate the brake light and fixed the radio.Get it home and the same day the radio goes into lock. Make the turn to come home and the brake light comes on.So I do some research. Find out that they had a bad brake sensor and faulty radios. So I take it back to the dealer.I tell them that the Cobalts have a brake sensor issue and the radio problem is also a common problem. I get the deer with the headlights in its eyes look. I tell them heres the deal, the car stays here till it is fixed right. While I'm telling them this a service tech walks in. He asks what the problem is. I tell him. the guys at the desk say there aren't any bulletins on the problems. He said Oh yes there is. Went on the computer and pulled them up. He told them if it isn't on paper - Look it up on the computer. So they put in an upgrade radio and a new sensor for the brakes. Haven't had a problem on either since.I realize it's a cheap car.But the cheap interior, got to go.It is below sub standard.I like the way it rides, looks and handles. We took 2 trips to Florida from PA. to visit my wifes family. We got a low of 38 miles to the gallon . We got as high as 48 MPG.That was doing it the old fashioned way.Check the miles vs the gallons used. Not the onboard computer.
OK, Now here is what I did today on it. I checked the ground. It is good. I checked to see if it is getting power to the fuel pump pressure tank. It is. So if it is getting power to both, what am I missing ? I noticed on the tank where the wires go into the plug that the unit looks like it should come out of the tank.It has what resembles a bayonet type mount.I also pushed in the Schrader valve. The first time I got a good air blast with more fuel that ever (but still not much ). I went back under and wired the fuel pump direct I let it run for maybe 3 seconds. Went abck and pressed the valve, no air, no gas.Back under to jump pump.Let it run about 5 seconds.Back out and push Schrader, nothing. Did that about 3 more times. Nothing.Gave up considered pouring gas over whole car and lighting it .But then thought my buddy would not appreciate it because it is in the bottom of his barn !!!

[rodeo02]

Everything is so computer/software driven today, that I'm thinking you've done all you can and need a scan with a Tech-II or what ever the Good Wrench dudes use to 'see' everything that's going on.

[J-Ri]

56Pontiac, I'm wondering if maybe the replacement pump was bad... even if the motor ran it doesn't necessarily mean the pump was pushing anything. If you're jumping power to the pump, it should have pressure at the schrader valve. Are you sure you have the polarity right? Reverse polarity will give no pressure but will make the pump run. Pull the pressure line off of the pump and clamp a hose over it going into a container suitable for fuel and run the pump. Just be very careful of sparks, I'd use long wires attached to the pump and then make the final connection away from the pump, I'd stay at least 10' away and make the connection a foot or two above the ground. If you've got fuel coming out there, you have a restriction in the line somewhere, maybe try blowing compressed air backwards through the line? There is also sometimes a small screen where the fuel line connects to the fuel rail, see if that is plugged. If there is no fuel there and you have the polarity correct, you have a bad pump.

Rodeo02, I work at an independent shop but we have a Tech-II, and really all you can do on it for this problem is command the fuel pump on, which can be done with jumper wires. Granted, it's much easier and faster than dropping the tank, but it's not as capable as everyone thinks. The only thing you need it for is SPS updates and a few body computers (radio, on-star, etc.). For the money, the Snap-on MODIS is much better (ignoring the proprietary GM software). The Tech-II is grayscale and has constant "scan lines" (or what were scan lines with a CRT, dunno for sure what LCD woud be called) if the car is running or has a battery charger on it. It also has no internal battery, which is at the very least irritating. It can also only graph 3 lines at once, and they have to be on the same graph.

[56pontiac]

Originally Posted by J-Ri

56Pontiac, I'm wondering if maybe the replacement pump was bad... even if the motor ran it doesn't necessarily mean the pump was pushing anything. If you're jumping power to the pump, it should have pressure at the schrader valve. Are you sure you have the polarity right? Reverse polarity will give no pressure but will make the pump run. Pull the pressure line off of the pump and clamp a hose over it going into a container suitable for fuel and run the pump. Just be very careful of sparks, I'd use long wires attached to the pump and then make the final connection away from the pump, I'd stay at least 10' away and make the connection a foot or two above the ground. If you've got fuel coming out there, you have a restriction in the line somewhere, maybe try blowing compressed air backwards through the line? There is also sometimes a small screen where the fuel line connects to the fuel rail, see if that is plugged. If there is no fuel there and you have the polarity correct, you have a bad pump.




Rodeo02, I work at an independent shop but we have a Tech-II, and really all you can do on it for this problem is command the fuel pump on, which can be done with jumper wires. Granted, it's much easier and faster than dropping the tank, but it's not as capable as everyone thinks. The only thing you need it for is SPS updates and a few body computers (radio, on-star, etc.). For the money, the Snap-on MODIS is much better (ignoring the proprietary GM software). The Tech-II is grayscale and has constant "scan lines" (or what were scan lines with a CRT, dunno for sure what LCD woud be called) if the car is running or has a battery charger on it. It also has no internal battery, which is at the very least irritating. It can also only graph 3 lines at once, and they have to be on the same graph.

The pump wont run at all from a command from the vehicle.I had to jump it from a hot wire I made that went from the battery in the trunk to the fuel pump.The old pump run when running a hot/ground wire. I'll try to see if it pumps actual gas like you say. I ordered a CEN TECH Code Reader CAN OBDll from Harbor Freight. Couldn't afford anything better. I know that when I test the contact coming out of the plug on the back of the pan behind the seat (Where the fuel pump plug is located ) that it does show power to it.But when I turn the key to start, the fuel pump won't run. If I jump wire it you can hear it. I will check to make sure the pump(s) actually pump and do not just run.Thanks,appreciate the help.

[56pontiac]

Originally Posted by 56pontiac

The pump wont run at all from a command from the vehicle.I had to jump it from a hot wire I made that went from the battery in the trunk to the fuel pump.The old pump run when running a hot/ground wire. I'll try to see if it pumps actual gas like you say. I ordered a CEN TECH Code Reader CAN OBDll from Harbor Freight. Couldn't afford anything better. I know that when I test the contact coming out of the plug on the back of the pan behind the seat (Where the fuel pump plug is located ) that it does show power to it.But when I turn the key to start, the fuel pump won't run. If I jump wire it you can hear it. I will check to make sure the pump(s) actually pump and do not just run.Thanks,appreciate the help.

UPDATE; Ok, I found out that there are 3 red hot wires to the plug for the fuel pump.They were covered with tar and only saw 2. The one that is getting power is the fuel gauge. Neither of the other 2 have power when the key is turned on.Had my buddy turn the key on while I had the test light on the terminals.Nothing.So we tested the fuse. There is no power to the fuse block for the fuel pump.All other fuses that should have power to them do. But the one for the pump is totally dead.I had checked earlier for blown fuse and changed the relay.The fuse was good, but changed it anyhow. Still waiting for the Code reader I ordered. FedEx is slower than Molasses in January. According to the tracking it won't be here for a week yet.Thanks again for the help.

[J-Ri]

A tip for the future, don't check to see if a fuse is blown, check for power to both sides of the fuses. It's quicker than removing the fuses to check them, and it shows if they have power to them as well. There are dual LED test lights that have a clamp for power an ground, then one color lights for hot and the other lights for ground. You can check every fuse and both sides of the circuit in about a minute. Hot both sides, fuse is good and has power; hot one side ground on the other, fuse is blown but the rest of the circuit is good; ground to both sides, fuse is good but doesn't have power. This is how I do it, so when you said the fuse was good, I assumed the wiring was good as well.

To test it further, run a fused jumper wire of the appropriate amperage to the "after" side of the fuse. All the fuses in that row of the box will get their power from the same side, so put it to the other side and see if it starts/runs. If it does, you can put the tank back up. You'll need a wiring diagram to see where the power for the fuel pump fuse comes from. Sometimes they go straight to B+ through a splice in the fuse box, other times they are one of several fuses that go through a larger fuse. That means that if you have checked every single fuse everywhere else on the car and the only fuse with no power to it is the fuel pump fuse, there is a problem in the wiring. Common places GM hides fuses from you include: Under the hood (can have multiple), both sides of the dash where the door closes against, under the dash, in the center console, under the rear seat, in the trunk. I havn't had to find them on a Cobalt yet, so check all those places for extra fuses, and don't look at it logically either (you need to think like an engineer). A wire can go from the battery and then through 3 fuse panels in different parts of the car before it goes to the device. You're getting very close to finding the problem, and it will probably be a cheap repair too.

[56pontiac]

Originally Posted by J-Ri

To test it further, run a fused jumper wire of the appropriate amperage to the "after" side of the fuse. All the fuses in that row of the box will get their power from the same side, so put it to the other side and see if it starts/runs. If it does, you can put the tank back up. You'll need a wiring diagram to see where the power for the fuel pump fuse comes from. Sometimes they go straight to B+ through a splice in the fuse box, other times they are one of several fuses that go through a larger fuse. That means that if you have checked every single fuse everywhere else on the car and the only fuse with no power to it is the fuel pump fuse, there is a problem in the wiring. Common places GM hides fuses from you include: Under the hood (can have multiple), both sides of the dash where the door closes against, under the dash, in the center console, under the rear seat, in the trunk. I havn't had to find them on a Cobalt yet, so check all those places for extra fuses, and don't look at it logically either (you need to think like an engineer). A wire can go from the battery and then through 3 fuse panels in different parts of the car before it goes to the device. You're getting very close to finding the problem, and it will probably be a cheap repair too.

The only other fuses that didn't power were the lights.They work, so they wouldn't power I guess till they are turned on.But every other fuse had power.The fuel pump relay ( In the fuse block ) can be heard clicking when the key was turned on.I did put a total of 3 different relays in and also changed the fuse.I've had fuses that looked good before and weren't.Didn't want to make that mistake again. But no power to either fuse. Next time I can get at the car will probably be Monday.So I'll do all that you suggested. My buddy had a Cavalier that had the same problem.He couldn't find why there was no power to the fuel pump. he decided to junk it.Him and another buddy started to tear it apart. When they took the dash out, a wire from the ignition was off.It was too late for that car !!Thanks,appreciate the info.

[J-Ri]

The relay clicks because the control side which activates the magnetic coil which pulls on the "switch" part of the relay and closes the circuit is good. From there, power flows through the "switch", but you have no power there which is why I suggested running a fused jumper wire to the after side of the fuse. Assuming the circuit between the fuse and the relay is good, the car should start as soon as all the air clears out of the fuel lines and rail.

[56pontiac]

Originally Posted by J-Ri

The relay clicks because the control side which activates the magnetic coil which pulls on the "switch" part of the relay and closes the circuit is good. From there, power flows through the "switch", but you have no power there which is why I suggested running a fused jumper wire to the after side of the fuse. Assuming the circuit between the fuse and the relay is good, the car should start as soon as all the air clears out of the fuel lines and rail.

First chance I get to go work on it I will try the jumper wire.Monday might be the soonest I can get at it. It's about a 25 minute to 1/2 hour drive each way. Thanks again.

[56pontiac]

Jump wired the fuel pump from another fuse. The pump runs. I put the tank back up in and it took a while to get the car started.Took the plugs out ( Can ony get 3 out.One is in so tight I'm afraid of stripping the threads. Using a 3/8 ratchet with a 12" extension the extension is bowig under the pressure ) and bead blasted them.It finally started. But it runs for maybe a minute at the longest and shuts down.It starts right back up again.I had noticed a kink in the hard plastic line going to the pressure tank (happened from having the tank suspended for so long I guess ) .I had squeezed it,but still has a narrow area where it was slightly bent.It seems like the problem with it not staying running is fuel related.It will kind of sputter and pop a little. Not an outright backfire.Next time I have a chance to work on it I think I'll drop the tank again and check to make sure that line isn't closed more than I think it is.I wouldn't think that the pump running all of the time should cause a fuel problem because I assume the excess fuel just goes back through the return line to the tank. At least it was great to hear it run for the first time in about 7 months. Thanks

[J-Ri]

Good to hear that it runs!

Find and fix the open in the wire between the fuse and battery, there's a chance that interfering with the circuit you jumped power from could be causing voltage problems for both circuits and making the engine die. After you do that (and if it still dies), I'd check the fuel pressure before dropping the tank again, these engines don't need even close to the 3/8" line that they have, mine will idle for 20 minutes on 12 oz of fuel injector cleaner which flows in through a 1/16" line. They use the same size line on almost all GM vehicles, the 454 V8s have the 3/8" just like our cars do. If that line was kinked to the point that it turned white on the sides where it was flat, I'd fix it, otherwise it's probably fine. They say "non-repairable" on them, but that just means with rubber hose. Carquest (and probably others) have repair kits for the hard nylon lines, you just have to use the parts in the kit, no using rubber hose or screw-clamps.

For that stuck plug, spray a little bit of penetrating oil down the hole and let it sit overnight or between working on it. That should make it much easier to get out. I've had some that were stuck pretty good, and I think I twisted my 12" extension about 1/8 of a turn before the plug came out with no problems. When you reinstall them, apply a light coating of nickel or copper (NOT the glass bead stuff) based anti-seize to the threads and the plug seat. Just don't get any on the electrode or you'll get a misfire if it bridges the gap. They'll turn out with no problem next time if you do that.

[56pontiac]

Originally Posted by J-Ri

Good to hear that it runs!

Find and fix the open in the wire between the fuse and battery, there's a chance that interfering with the circuit you jumped power from could be causing voltage problems for both circuits and making the engine die. After you do that (and if it still dies), I'd check the fuel pressure before dropping the tank again, these engines don't need even close to the 3/8" line that they have, mine will idle for 20 minutes on 12 oz of fuel injector cleaner which flows in through a 1/16" line. They use the same size line on almost all GM vehicles, the 454 V8s have the 3/8" just like our cars do. If that line was kinked to the point that it turned white on the sides where it was flat, I'd fix it, otherwise it's probably fine. They say "non-repairable" on them, but that just means with rubber hose. Carquest (and probably others) have repair kits for the hard nylon lines, you just have to use the parts in the kit, no using rubber hose or screw-clamps.

For that stuck plug, spray a little bit of penetrating oil down the hole and let it sit overnight or between working on it. That should make it much easier to get out. I've had some that were stuck pretty good, and I think I twisted my 12" extension about 1/8 of a turn before the plug came out with no problems. When you reinstall them, apply a light coating of nickel or copper (NOT the glass bead stuff) based anti-seize to the threads and the plug seat. Just don't get any on the electrode or you'll get a misfire if it bridges the gap. They'll turn out with no problem next time if you do that.

Thanks again. I'll check the wire next time I get out to the car. My problem is that I have to stay home and keep an eye on my Mom who has late stage Alzheimers.My wife works and I can't leave my Mom alone.Area Agecy On Aging comes out this week to see her.Then we have to start the hated process of putting her in a home. I don't have a garage and have the car at a friends place in the bottom of his barn.If the car were here I'd be able to spend more time on it.Thanks.

[rodeo02]

All else fails with that stuck spark plug; Did you try to snug it slightly first? I've had luck getting them out of aluminum that way. Definitely try PBblaster or the likes first.

Joel

[56pontiac]

Originally Posted by rodeo02

All else fails with that stuck spark plug; Did you try to snug it slightly first? I've had luck getting them out of aluminum that way. Definitely try PBblaster or the likes first.

Joel

We did try to snug it after we tried to loosen it.Seemed like it did just that ....made it tighter.I was going to put PB Blaster on it and forgot. If I don't get it out now it will get done when I change the head gasket. Hate the aluminum junk.Never liked it, never will. Aluminum to lighten the load to up the MPG as per what the Govt wants. Wish they would get rid of the cat, put on a less restrictive exhaust and eliminate all the pollution garbage and pick up more MPG's that way. Then go back to cast iron. Then get on China's case who pollutes more than every other country combined.Thanks and I will post what happens next time I work on it.

[J-Ri]

If the plug did tighten, then the threads can either move freely or are already stripped, I'd just back it out and cross your fingers. I've done more spark plugs than I can count in aluminum heads, at first I thought the threads would pull out on half of them, but I havn't had a single one pull any out. The funny thing is, the only time I did have the threads pull out was on a cast iron head

I know what you're saying about aluminum, but it definitely has it's upsides too. A Cavalier with the cast iron 2.4l handles and rides worse than the same car with the 2.2 Ecotec. Not much, but it is noticeable if you really get going . You also have more HP to accelerate because you're not moving all that weight with you. The latest version of the 2.4 Quad4 makes 5 HP more than the 2.2 Ecotec, yet is slower.

Use anti-seize, change fluids on time, and use a torque wrench... pretty much all you need to do with aluminum.