2003 Tahoe crank no start HELP!!!

[65oldsboy]

I swapped the relay with a known working relay...no help. I have power to the relay and power to both fuses. I can't get to the connector at the fuel pump without dropping the (FULL) gas tank. The truck was in my driveway, which has an upward grade toward the house. I drifted it out to the street so that I could get my other car out of the garage. I can't even get the truck into the garage to work on it. I'm not willing to drop the tank in the street and be worried about having the truck get bumped with me under it.

[cywelchjr]

I swapped the relay with a known working relay...no help. I have power to the relay and power to both fuses. I can't get to the connector at the fuel pump without dropping the (FULL) gas tank. The truck was in my driveway, which has an upward grade toward the house. I drifted it out to the street so that I could get my other car out of the garage. I can't even get the truck into the garage to work on it. I'm not willing to drop the tank in the street and be worried about having the truck get bumped with me under it.

I can understand your problems. That said, the symptoms seem to be pointing to a bad fuel pump, and the ONLY way to know is to find out if you have power to the pump, if you do, then the pump is bad.

[Montreux_Blue]

Not sure if you have changed a fuel pump before but do you know how full the tank is? I would siphon as much out as possible since gas weighs about 6.6 lbs per gallon. Changing a fuel pump is a one man job, at least it has been for me the handful + times I've done it, but getting back up the driveway might take a few people.

[65oldsboy]

Just got home from work and going to give it one more try. I think its probably the fuel pump. I just filled her up the day before the problem and the tank holds 26 gallons. If the clear codes/battery/fuse thing doesn't work then I'm gonna be a big girl and let a professional do it. I know it will cost $200-300 more than if I do it myself but its mostly a safety issue now that the car is in the street. Plus, where am I going to put 20+ gallons of gas??? I have changed one other fuel pump before. On that car, the fuel pump connector was accessible and I checked the connector for power before dropping the tank.

[Montreux_Blue]

On that car, the fuel pump connector was accessible and I checked the connector for power before dropping the tank.

A foreign car obviously! If I lived close by I would have helped you. As far as where to put the gas, I had to "relocate" 3/4 of a 44 gallon tank on my Suburban, I put some in the lawn mower, edger, weedeater, motorcycle, all my gas cans, girlfriends car, my moms car,............anything that used gas and still had probably 10 gallons left in it. I just used a jack to lower and raise it back into place.

[XJOK2PLAY]

65 Oldsboy...

I used to be a fleet mechanic, and I used to own one of these. GM has had a lot of issues w/ fuel pumps and their failures. Ironically, it many times happens immediately after a fill up, which really sucks, since the tanks gotta come down. The screens (sock) on the pumps don't work that well, so running it low or on empty is a bad deal.
My suggestion... get ready to drop the tank and spend some bucks... mine cost me $425. (400 for the sending unit portion you don't need, 25 for the little Mickey Mouse electric pump that looks like it should be powering a toy electric car, + labor if you choose not to do it yourself.) If you can find out the exact readings you should have at the pump, you could confirm it's getting there, and then confirm the pump's bit the dust. But a word of caution... don't just put a DVOM on the terminals and expect a 12 V. reading... all that circuit connects back to the CPU, and can cause some additional serious issues if your not careful. I would try to consult a Chilton's or other tech manual or a Chevy dealer for the proper testing procedure first.
More than likely, if you turn the key, don't hear the pump, and can affirm the correct voltage at the pump, you've just become another one of the General's long list of statistics. They've known about these sorry pumps they've been using for a decade now, but won't address the problem.
Sorry to say, but welcome to the club. Mine stranded me in the middle of nowhere, and yes... I had just filled up, too!

[xs1100rider]

fuel pump

i had to replace mine in SWMBOs suburban twice before i got a good one, and after doing so i talked to the shop foreman on campus(work for CU/boulder) and he said there was a nationwide shortage of the gm fuel pumps due to them going out so much.they were waiting for one to come in on a gmc that had just come offf warranty a week before.good luck with it.

[XJOK2PLAY]

Adding...

It is ironic .... the timing coincidence with the blower relay. I'm very sure the two are not related. Two seperate issues. I used to hate it when that would happen... change a fan belt and the tire would go flat kinda deal...
I wish you good luck!
Bob

[65oldsboy]

Well, I had it dragged off to the repair shop last night. I just got a call from them 15 minutes ago and guess what? It started right up for them this morning. YEAH, an intermittent electrical problem!! I guess that just bouncing it around getting it on and off of the tow truck was enough to reconnect some bad connection. Really has the symptoms of a bad fuel pump now. I guess I will spend Memorial Day changing a fuel pump. If it doesn't crap out again before then, I can at least drive it around and get rid of some of the gas in the tank. Advance Auto Parts has an aftermarket pump for about $275. Can that possibly be more of a POS than the original GM fuel pump?

[Varnae]

I had a 2003 Chevy Z71 that I bought used. When I went and looked at it I noticed that the fuel pump was louder than normal. I told them and they took it to the mechanic who said it was fine. I drove it home that night and the next day on the way to work it started sputtering and jerking every time I pushed on the gas pedal, though it would idle just fine. I idled it all the way back to the dealership and they had the mechanic check it out. Guess what? I was right. They had to replace the fuel pump.

My dad has a '99 GMC 1500. I noticed again that the fuel pump hum seemed to be a little bit louder than normal. I told him he might wanna get that checked out. He was taking me back to my house that evening and sure enough, the fuel pump died on us. We had to have it towed back to his mechanic and get my brother in law to give us a ride to my house.

[Ivan]

The only test you have left is a voltage test at the fuel pump. pull the connector near the tank and test for voltage when the key is turned on. You should get a 2-3 second burst. On some of the newer stuff the fuel pump is computer controlled with a duty cycle to create a variable speed. Not sure this is the case on an 03 or not. The test for that is to put your meter on Hz and look for a reading when cranking.

In all my years of replacing fuel pumps, I have never found a bad relay or a blown fuse. Not saying it doesnt happen, but it is far more likely that the pump goes out. What I have found to be the case id that they do not tolerate being run dry. Fuel through the pump cools it, and running it dry over heats it. If you have run out of fuel in the recent past, I would say the pump went out more than likely.

As far as replacement, siphon the fuel out, and drop the tank. Pretty easy when its empty. I didnt even drop them clear out when I did the SUVs. I just loosened one of the straps and undid the other, enough that the tank would drop a bit. Then pulled the pump. It was almost a waste of time to put it on a lift. If it has a plastic tank with a threaded "mason jar" ring on it, a set of oil filter pliers works really well on that, which makes it easy. GM was famous for their quick connects that never came loose easily. The easy way to handle that is to make suew all the dirt and road grime is cleaned out of the connector before inserting the tool to release it. It never worked with dirt behind the fingers so they couldnt come loose, but some simple green and a shot of compressed air to clean it out made them work super easy.

One final thought. GM CFI had poppets in the plenum. The Vortec V6 and V8 were very famous for having fuel pressure and still a no fuel condition. What we soon realized was that a weak pump was as good as no pump. If it didnt make 53(?) psi, it would not open the poppet valves and no fuel would flow. at 54 psi. it would run like a champ. (those numbers may not be right, but you get the idea)

Goodd luck...

[cywelchjr]

This is well known in electronics. This is the design plan of having the $200 pump burn itself out to protect the $20 relay and the 50 cent fuse.

[65oldsboy]

Fuel through the pump cools it, and running it dry over heats it. If you have run out of fuel in the recent past, I would say the pump went out more than likely.

As far as replacement, siphon the fuel out, and drop the tank. Pretty easy when its empty. I didnt even drop them clear out when I did the SUVs. I just loosened one of the straps and undid the other, enough that the tank would drop a bit. Then pulled the pump. It was almost a waste of time to put it on a lift. If it has a plastic tank with a threaded "mason jar" ring on it, a set of oil filter pliers works really well on that, which makes it easy. GM was famous for their quick connects that never came loose easily. The easy way to handle that is to make suew all the dirt and road grime is cleaned out of the connector before inserting the tool to release it. It never worked with dirt behind the fingers so they couldnt come loose, but some simple green and a shot of compressed air to clean it out made them work super easy.

One final thought. GM CFI had poppets in the plenum. The Vortec V6 and V8 were very famous for having fuel pressure and still a no fuel condition. What we soon realized was that a weak pump was as good as no pump. If it didnt make 53(?) psi, it would not open the poppet valves and no fuel would flow. at 54 psi. it would run like a champ. (those numbers may not be right, but you get the idea)

Goodd luck...

Thanks for the tips. This should help. I have never run out of gas completely but have let it get pretty close. It was really low when I filled her up a few days ago. Even if it does run for the next few days, I'm gonna replace the pump.

[cywelchjr]

Well, I had it dragged off to the repair shop last night. I just got a call from them 15 minutes ago and guess what? It started right up for them this morning. YEAH, an intermittent electrical problem!! I guess that just bouncing it around getting it on and off of the tow truck was enough to reconnect some bad connection. Really has the symptoms of a bad fuel pump now. I guess I will spend Memorial Day changing a fuel pump. If it doesn't crap out again before then, I can at least drive it around and get rid of some of the gas in the tank. Advance Auto Parts has an aftermarket pump for about $275. Can that possibly be more of a POS than the original GM fuel pump?

I think the aftermarket pumps are generally at least as good if not better than the original. I went with aftermarket on my Malibu, just couldn't make myself spend an extra $100 for the OEM pump (just like I can't seem to make myself type properly this morning. Kept mistyping the same word the same way ).

[magnum440]

I don't know why this works, but I've tried it before and it worked for me. If it quits working again, try hitting the bottum of the tank with a rubber mallet. You don't have to knock the crap out of it, just a good solid smack or two. On most vehicles, you can see a low place on the bottum of the tank. this is usually where the pump is located. the only thing I can figure is that it must jar the pump enough to get it working. It has gotten me home in two different vehicles and one of those was an '02 Tahoe. At least if it works, you will know it is the pump. And you could also get to burn up some of the gas. Both of my pumps that went out were intermitent. My Dakota made it almost a year before it quit completly