Well, I've read a lot of posts here about this subject, but still wanted to get some opinions on this.

Last night, my son's car just died as he was pulling into the gas station. When trying to restart the car, it never tried to fire. I checked for spark and timing and all thats fine. After towing it home, I checked for fuel pressure using the schrader valve on the fuel rail. My guage showed 0 psi. I checked to ensure the gauge was seated properly and that the gauge was working properly by testing it on the other camaro. Did just fine. So, I turned the ignition to ON and pushed in on the schrader valve and the fuel essentially just oozed from the valve, it did not spray or run out quickly.

I can hear the fuel pump energize and the relay engage (on the driver's side). I have to wonder if the fuel pressure regulator could maybe be the cause (its the original one from 86). I have not disconnected the hard fuel line where it attaches to the rail to see how the fuel flows from there.

I've also read about what its like when the pumps go bad, or the line is split in the tank and the damper in the tank not sealing well, etc.

I've never dropped the gas tank before so I was wondering how difficult a job that is and reading the manual, it sounds extremely involved (removing the springs, dropping the exhaust, etc)

I was wondering if hooking up a carburated fuel pump would work ok with the TPI system?

The other thing that is weird is that his alarm system (after market) is also now not working properly. It is only a starter cutout and not ignition or fuel pump cutout. So I was wondering that if something has grounded or is not grounded, could also cause this kind of issue with not getting fuel pressure?

Thanks,

Pat

 

If the security system doesn't disable the ignition or fuel pump, it shouldn't have anything to do with your fuel issue. But, some weird things are done out there.

You might try blocking off/restricting the regulator return and check for pressure. Just be cautious, because if it is the reg, the pressure can get pretty high quickly with no return.

 

Thanks for the reply, I really appreciate it!!

Which line is that going to be? I always forget which is which!

thanks,

Pat

 

fuel filter as well

 

The larger one is supply, smaller one return.

 

Ok, I tried pinching the lines and no change. I also forgot to mention something else. The gas tank is about half full, but after the car failed to start, it is pegged clear up at the top, past the full mark, its totally vertical.

I pulled the negative off the battery and now the alarm system is working fine. The battery had got pretty worn down from all the times trying to start it, but I did get it charged back up using my battery charger.

I would be tempted to replace the fuel filter and possibly the fuel relay, but I jumpered the oil pressure sensor switch which leads to the fuel pump to activate it. It runs but it doesn't sound as strong as it used to plus, the fuel pressure is simply not there.

I just don't want to have to pull down the tank and replace it all, only to find thats not it. :-)

Based upon the info I've given, does it sound like the fuel pump to you all? Also, how can I check for 12 volts to the pump without dropping the tank?

And lastly, anyone have any tips on dropping the tank?

Thanks,

Pat

 

i had the same problem once before, turns out that i dropped the tank and everything and it was something completely different. so first are u totally positive its the fuel?

try starting it with starter fuel and if it does then yes its the culprit. next before u go dropping the rear axle and springs and exhaust make sure the little connector by the battery is connected, its a big connector and it makes the fuel pump turn on. also switch out the fuel filter its only like 10 bucks and you might aswell change it because its probably due for a new one anyways

but anyways if all that stuff didnt work then its probably the fuel pump. one tip ill give you is empty the fuel tank, if your gonna be working on it without a lift then this will make everything go so much more smoother. also have someone help you out. that tank is heavy when its half full, so make sure to get a good amount out of there.

also the carburator pump wont work, seeing as how fuel injection uses alot more pressure

 

Thanks for the replies!!

I will definitely replace the fuel filter tomorrow, but looks like I won't be able to get back to this thing until Sunday as I'm driving from the KC area to St. Louis to move my daughter there. Bittersweet, but that's another story!

I'm not sure how I would try and start the car with starting fluid/ether, I've got the tpi, so I guess I could spray some in the throttle body and see what goes from there. I did check and verify that I had spark, so that much I know is good. I also checked the pick-up coil, ignition module, etc.

The little connector by the battery, I'm not sure which one that is. There is one there for the fan relay, but there is also one on the fender wall, is that the one you're referring to?

I'm pretty sure that the fuel pressure is the culprit as last year I had rebuilt the engine and when testing, I hooked up the fuel pressure gauge to it and had right around 40psi, and when I pressed on the schrader valve back then it would spray everywhere. Now when I press the schrader valve, the gas kind oozes out and doesn't spray out. And when I hook the fuel pressure gauge, it reads 0 psi.

Anyway, I was wanting to double-check everything to ensure it wasn't a short somewhere. I am confused as to what's going on with the fuel level gauge being pegged like it is. That's why I was wondering if maybe a short, but everything else electrical appears to be working fine (lights, stereo, windows, hatch, car alarm (it has no fuel cutoff, only starter disable, and I installed this one), etc.

Also, I noticed you stated about dropping the rear axle. Do I have to do that in order to get the tank out? Also, when I was looking up underneath, I don't see why I would need to drop the springs off to get the tank out. The exhaust is obvious, but couldn't quite see the reason for the springs.

Thanks for all the help, suggestions, and advice. I really appreciate it all. And sorry for the long posts!

Thanks,

Pat

 

Ok, another update.

I shot some starting spray/ether into the throttle body and she fired right up. I also checked the connector on the passenger fender and it had a 10amp fuse in the end of it, and the fuse was good -- checked it on my meter.

So, I also replaced the fuel pressure relay since it fairly cheap, forgot to mention that on my last post, so we can rule that out as well. Plus, I took readings of the new one and the old one and both were the same.

So, its beginning to look more and more like the fuel pump. I will go ahead and replace the fuel filter tomorrow, but in all honesty, I think its going to be the pump. If it was the fuel filter, that would be pretty sad and would indicate I need to clean the tank anyways, right?

Thanks again,

Pat

 

One other thing. It seems like I remember reading a post somewhere on here where someone cut a hole from the top side in order to get to the fuel pump.

I don't know how well that would work or safe it would be. Thoughts??

Thanks,

Pat

 

the problem that i had was that my cat was welded on, so the only place to unbolt the exhaust was from the bottom of the headers, so what i had to do was lift it up high enough, take off the heat shield, unbolt the exhaust hooks and move it out of the way and then undo the tank straps and the bolts where u fill up, it makes it easier if the plastic is out of the way. but about the rear axle i had a problem because i unbolted the exhaust and moved it and the tank was basically dangling but it just wouldnt slip out any way i moved it, and it was over halfway full so it was pretty fricken heavy, after an hour of struggling i had to face that i was gonna have to undo the sway bar and the panhard bar and drop down the axle, after that it was cake.

dont go the half assed way and cut the trunk area, you wont have enough room to spin that circle clip ontop of the tank.

 

I wouldnt suggest cutting a hole back there. It will give you access....but dropping a tank is NOT hard.

Raise the back end of the car up, fairly high if you can. You will have to unplug the fuel lines, and wires going into the fuel pump. Also the filler neck. Im not sure on these cars if anything else has to be removed, like the back section of the exhaust or not. Then after that just unbolt the 2 straps that hold the tank up, and out it comes. Most fuel tanks are pretty easy to drop. It sounds like you are a bright guy, so you should have no trouble. Good luck

 

ive dropped a couple of tanks and its pretty simple with the right tools and making sure everythings unhooked. i suppose if you want too you could cut a hole back there but it would be much easier just to drop the tank anyways.

 

Thanks again everyone for all the replies and advice, believe me, its not falling on deaf ears!

I will go ahead and drop the tank then and take it from there. A couple lessons my dad always taught me was, "if you're going to do it, do it right", and the 2nd was "if you don't have the time to do it right the first time, when will you find the time to do it right later?". :-)

I guess I'm a little worried about having to drop the axle and all, but hopefully once I get started, it won't be as bad as I'm anticipating.

I won't be able to get to this until Sunday, so it will be a few days before I post back.

Thank for all the great advice!

Pat

 

you dont have to drop the rear axle completly

leave the control arms, driveshaft, and torque arm connected

disconnect the shocks, panhard bar, and sway bar links

cut the exhaust and have a shop weld it together if you dont have a welder

 

Well, thought I'd give everyone a quick update.

Once I got started, I found it wasn't as much as a PITA as I had envisioned. What was though, was getting some of the bolts to bust loose. I had to cut the bolts off to the muffler, they just wouldn't budge, even though I had used plenty of penetrating oil on them on Friday, a touch Saturday before I left for St. Louis, and then this morning. Also, the bolts for the sway bar linkages would not budge either. Luckily, I was able to get the tank out without removing those bolts.

I had to cut my exhaust however even though there was a splice there with a u-bolt. It wouldn't budge and after a couple hours of trying, I just decided to cut it off.

The tank came out with a little bit of difficulty, but once out I got the fuel pump out. found the problem immediately. For the pump was separated from the GM junction box that connects the pump to the fuel line. Also, the other fuel line that the fuel level gauge connects to was broken, so that leads me to believe that someone had been in there previously.

I assume the pump is still good, it just couldn't pump fuel since it was disconnected from the line. I am replacing it anyway as I'm a believer in replacing things while I'm there!

My concern is the return fuel line since it is broken. I don't think its too big of a deal since it is the return line. My only concern is the fuel level gauge and its functionality. It will be attached and upright but only due to the fuel line I'm going to use to replace that GM junction connector/box.

A new fuel sending unit is just under $200 and in all honesty, I don't feel like dropping another tank at a junk yard! I think I may try and tack it back on and in place.

What do you all think?

Thanks,

Pat

 

make sure u check the resistance of the wire going to your gauge while moving the arm up and down

 

Thanks for the replies!!

Well, I completed the car yesterday as Monday I had taken the fuel sending unit to a local shop and had the broken line brazed together. They did a pretty good job. In the meantime, since I was waiting for them to do that, I did some work on items I had been putting off, such as putting in the rear header bolt that had fallen out on the passenger side, tidy'd up the plug wires, changed the oil, flushed the radiator, etc.

I bought a new wiring kit for the fuel pump and got it all installed. I replaced the pulse damper with fuel line and clamps. Geez, that fuel line that is submergible is expensive. It ran me $24 a foot and I checked around at several car part places and garages. The spec on the fuel line is SAE J30R10 in case anyone else is considering the same.

The car fired right up and all is well. Now I need to figure out the rough idle which has been occurring for a while now, pretty sure its the coolant temp sensor, but this would be another post and not to bring up in detail here!

Thanks everyone for the help and advice, I really appreciate it!

Pat