joeb Posted August 31, 2005 Report Share Posted August 31, 2005 my 96 STS will crank but not start. tank area seems awful quiet. checked the fuses and relay. I have the car home so I am planning on dropping the tank. I have done other FI cars before. at least my intrepid had a fuel pump access thru the trunk. that was nice. I know its a lot of work to drop the tank and than check the fuel pump for operation but I was wondering if there was any other way to check it in the car? Link to comment Share on other sites More sharing options...
DaveC Posted August 31, 2005 Report Share Posted August 31, 2005 Before going after the fuel pump you should check the fuel pressure. If the pressure is good your starting problem is not with the pump. You can check the pressure at the service valve on the fuel rail near the front driver side of the engine. Good luck. DaveC Link to comment Share on other sites More sharing options...
sal.carceller@cox.net Posted August 31, 2005 Report Share Posted August 31, 2005 I have a 93 Seville and did a fuel pump replace about 3 years ago. First I bought a pump from NAPA (just the pump not the entire assembly) the pump looked the same but after going through all the trouble it only produced about 50lbs so I had to drop the tank again and purchase the pump as an entire AC Delco assembly much more money about $200.00 if I recall corectly. Just thought I'd share this bad experience with you. One other thing was that within the assembly the pump has a clear plastic hose that connect the pump to the assembly case this hose should be carefully inspected for pin holes. The hose is an accordion style hose and you can't buy this part it only comes if you get the pump assembly. I mention this because my hose had pin holes resulting in low pressure at the rail. Many folks suspect one common cause of pump and assembly failure is due to fuel additives, I no longer add anything to my fuel tank. I don't recall exactly but i think you may be able to test to see if the pump wires are getting +12v without removing the tank, I think you will find an electrical conector that feeds the pump near the back of the tank. If you do not hear anything at the tank when you turn the ignition on the pump most likely is not running. You don't even need to go to the crank/start position with engine off turn the key to the ignition position (the one right before the crank position) the pump should run for about 5 seconds or so and you should hear it. It does this to pressurize the fuel rail before you actually start cranking. My suggestion is to be sure all electrical is OK before you drop the tank. Link to comment Share on other sites More sharing options...
CaddyChris Posted August 31, 2005 Report Share Posted August 31, 2005 you can also try to bang the bottom of the gas tank with a hammer and see if that gets it going. My 94 left me stranded and I checked for spark, it had it. Than I sprayed some brake clean in the intake to see if it was a mechanical problem, nope, it tried to light up. Then, as a last resort I banged the bottom of the tank with a hammer a few times. I went to start the car and it fired right up. I made it home 15 miles w/o a problem. I got lucky, tried to start the car after that to no avail. I replaced the fuel pump, not the whole assembly...and it is tricky. As mentioned, the assembly is fragile with that little accoridian hose. Also, be very careful when putting it back together to make sure the seal at the top of the tank seals properly. I don't know about 96 but my 94 had a goofy plastic screw that was nearly impossible to get started. I thought i had it, put it all back together. A month later I topped off and fuel was leaking...turns out I didn't have it on all the way. Had to drop the tank again....that was fun. Chris Christopher Petro 94 sts 67 coupe de Ville Link to comment Share on other sites More sharing options...
joeb Posted September 1, 2005 Author Report Share Posted September 1, 2005 key on and i hear nothing from the tank area. I have the car up on ramps and jackstands now. i found a light colored 5 pin connector at the rear of the tank. I assume this is the FP harness. now to get the gas out. I have a nice electric pump that can use either 1/4 or 3/8 tubing. i tried to snake both tubes down the filler tube but there are a few sharp bends. would it be easier to take off the driver side rear wheel and try and reach in and pull the steel fill tube out of the rubber sleeve that goes into the tank? seems awful tight since the rear suspension crossmember is in this area. i have to get the gas out somehow or at least i want to before dropping the tank. Link to comment Share on other sites More sharing options...
acklac7 Posted September 1, 2005 Report Share Posted September 1, 2005 would it be easier to take off the driver side rear wheel and try and reach in and pull the steel fill tube out of the rubber sleeve that goes into the tank? seems awful tight since the rear suspension crossmember is in this area. i have to get the gas out somehow or at least i want to before dropping the tank. Had my pump go out...what fun...Someone on here had there pump go out a few days after mine and I was able to recall almost every step of the job!...This should help....In regards to your post....There is a baffle inside the filler hose, and unfortunately you can't stick a hose down there ....So you have to disconnect the filler hose at the tank...And yes it is a BEAR to get off with the cross member just inches away....I believe I used a $2 hose clamp and a flathead screwdriver (which was used as a lever to "pry" the hose lose) ....And it wasn't easy...Probably took me a good 45 min just messing with the hoses!.......If you find yourself cursing at the fuel tank try to remember that your saving about $400 dollars doing it yourself...Should alleviate some of the tension....LoL "Dropping the tank was easy, the hard part is removing the gas. I had to spend 1-2 (messy) hours draining the tank. First I removed the two hoses at the end of the tank and drained most of the gas (with a hand pump). Then I placed two jacks under the tank and put a board on top them. Cranked one jack up, then the other, until the board was flush with the fuel tank. Remove the 4? bolts on each of the "straps". At this point the fuel tank is free, but now you have to worry about maneuvering the exhaust heat shield out of the way...which was a MAJOR pain in the *smurf*. You have to remove 4 or 5 screws from the heat shield and maneuver it back and fourth until there is room for the tank to slip out. Once you have the shield out of the way slowly release the pressure from the jacks and lower the fuel tank. Watch out when lowering the tank because the fuel lines will need to be disconnected in order for the tank to come all the way down. Drop the tank a little and then disconnect the fuel lines, then you can drop it all the way down. Replacing the pump is fairly straight forward, just swap it out, and jack the (drained) tank back up into position and put bolts/screws back in...Took me about 5 hours the first time, I could probably do it in 2 now....Having a tank on E helps tremendously."..... Good Luck! A.J. Link to comment Share on other sites More sharing options...
Scotty Posted September 1, 2005 Report Share Posted September 1, 2005 I know that I don't have to say this but I will anyway, empty gas containers or gas containers with a small amount of fuel are MUCH more dangerous that full containers, be very careful and don't leave the hole where the fuel pump open too long so that fumes can lay around the tank, a spark can be disastrous... keep an extinguisher nearby, just in case.. Be careful with fumes, and be careful where you pump the fuel to and what you pump the fuel with, those drill type pumps are dangerous due to the open sparks on the armature. no open fires, cigarettes, etc.. Good Luck, Mike Link to comment Share on other sites More sharing options...
joeb Posted September 2, 2005 Author Report Share Posted September 2, 2005 success. the old pump is out and new pump assy is in. I had help sliding the tank back into position so that was nice. I plugged in the pump before I installed it and turned the key and it ran so I knew I was on the right track. I have heard that the wire harness from the pump motor to the pump connector was suspect but I have not inspected the old pump yet. maybe later. at least the car is running. Link to comment Share on other sites More sharing options...
Scotty Posted September 3, 2005 Report Share Posted September 3, 2005 Good Job, I have never done it, and don't look forward to ever doing it! Glad you fixed it.. Mike Link to comment Share on other sites More sharing options...
joeb Posted September 10, 2005 Author Report Share Posted September 10, 2005 to add insult to injury, i took apart the FP and the pump was fine. i inspected the wire harness and i found a good bit of corrosion on 1 of the contacts. ahh, that makes me feel better. putting in a new FP to fix a 50 cent connector. Link to comment Share on other sites More sharing options...
Scotty Posted September 10, 2005 Report Share Posted September 10, 2005 That's a shame but you would not have dropped your fuel tank without having a replacement on hand and it may have been risky attempting to repair that connector and then to reinstall it. The natural thing to do once you go through the trouble to drop the tank is to replace the fuel pump, hey its 10 years old, now you no longer need to worry about it... Did you find any dirt, grit or debris in the in tank filter when you took it out? Was this the external connector at the tank? Link to comment Share on other sites More sharing options...
joeb Posted September 10, 2005 Author Report Share Posted September 10, 2005 dang right. i was not dropping the tank without a replacement pump handy.but you have to analyze the situation. the car did not run. so i was dead in the water. does not really matter if the pump was bad or a little wire was broke. the car was NOT running. gotta do something. the corrosion was at an internal connection. the screen was clean. no debris. looking at all the exposed wiring inside the FP assembly makes me wonder why cars are not subject to fuel tank explosions. makes me thing of flight TWA flight 800? that blew up near long island several yrs ago. did you know the FAA is looking at a nitrogen injection system for airlinler fuel tanks? very cool. at least i now have a spare fuel pump. i hope i never have to use it. Link to comment Share on other sites More sharing options...
Scotty Posted September 10, 2005 Report Share Posted September 10, 2005 I am like you I take things apart to see why they didn't work also. We had this discussion a few years ago with the guru, I think, and somebody correct me if I am wrong, the pump is submerged in fuel and there is no oxygen for an explosion, plus the fuel cools the pump. We had this discussion right around the TWA flight 800 disaster when someone took their pump out and the insulation on the wires was melted.. Link to comment Share on other sites More sharing options...
KHE Posted September 10, 2005 Report Share Posted September 10, 2005 The concentration of fuel fapors in the tank is so high that you couldn't start a fire inside there if you had to... the fuel vapors displace most (all?) of the available oxygen in the tank. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
Scotty Posted September 11, 2005 Report Share Posted September 11, 2005 The concentration of fuel fapors in the tank is so high that you couldn't start a fire inside there if you had to... the fuel vapors displace most (all?) of the available oxygen in the tank. Yes I think that was the explanation all fuel vapor and no oxygen, sort of like throwing a match in a bucket of gas (not that I would ever test that!) That is a good episode for MYTH BUSTERS! Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.