No pressure
03-17-2004, 01:00 PM
#1
Guest
Posts: n/a
No pressure
Hello to all. I'm new to this forum but not to Z cars. This is my latest find. It's a 78 that's been sitting abandoned for the past ten years. Needless to say it's pretty rough but almost rust free. I took her home on a trailer and changed her oil and filter. Put in new plugs and decided what the heck and put in a battery from one of my other cars and Holy crap. it started!! She didn't smoke and idled pretty smooth at around 700 rpm. This is a five speed car by the way. I couldn't believe it! Ten years and the thing fired up like it was driven yesterday!! Now the problem, well one of many I'm sure. The car ran fine for about five minutes and then died. Now she won't start again. Has no fuel pressure. I've drained the old gas out and replaced the filter. I even changed the pump even though the old one was running. I blew compressed air through the fuel lines from the tank forward. Put in fresh gas (4 gallons). The pump comes on when I turn the ignition on but I'm not getting anything from the fuel line to the rail. The pump runs the whole time the key is on. If I put my finger over the end of the hose with the key on I feel very little pressure and get maybe a couple of teaspoons of gas when I let it go. Is there something I'm missing here??!! I even tried blowing air through the gas lines cominf out of the tank itself. There's two on this car. The top one seemed to be free as I could feel the air coming out through the cap. The bottom one didn't seem to let the air go through. Is this right?? The top line is the one connected to the fuel pump inlet. This looks kind of odd to me because that line is almost halfway up the tank unless the tube extends down inside the tank, otherwise it seems like it would be hard for the pump to pick up the last half tank of fuel! Sorry for being so long but I thought as many details as possible might help. Any ideas on why I can't get any pressure? This is my first fuel injected Z so any ideas would be greatly appreciated. Thanks guys and gals.
03-18-2004, 08:30 AM
#3
Registered User
Join Date: Nov 2003
Location: Gerber, CA
Posts: 3,672
I agree with allmyzs. Sounds like you have a clog in the fuel line. You could try using a coat hanger as a 'feeler' to see if you can feel the clog. With any luck you'll be able to find the clog this way.
03-18-2004, 08:36 AM
#4
Guest
Posts: n/a
go get some fuel line long enough to reach from the fuel pump to the rail. If the car runs then you know you need to change your fuel lines. Or find where the clog is and remove it. I have heard that acetone will clean the metal lines but dont uise on the rubber, it will eat right thru it.
03-18-2004, 11:14 AM
#5
Registered User
Join Date: Jan 2004
Location: Seattle, Wa
Posts: 82
no pressure
Its not unusual for a Z to start after long years, they are great feats of engineering, but I think you probably sucked up junk that was sitting in the bottom of the tank.
As you noted there are two lines, the top on being the fuel return line which rarely if ever clogs.
The bottom line is the work horse, you can't blow it backward because the fuel dampener and the fuel pump itself won't allow reverse flow. Thats the good news! The work begins with draining the tank, theres a large plug on the bottom of the tank. Drain it out and look for debris. If you have alot you need to flush out the tank and will probably need to remove the sending unit to clean out the gas pick up tube and it's screen. Its a chore but remember you won't have to do it again if you keep the tank clean.
Since you are under the car at this point you can change out the fuel lines and save a hassle later. See other postings about fuel lines (their are not your grandfathers Ford style)
DO NOT EVER, FOR ANY REASON, introduce acetone or any other solvent into the fuel sytem or for that matter coat hangers!
As you noted there are two lines, the top on being the fuel return line which rarely if ever clogs.
The bottom line is the work horse, you can't blow it backward because the fuel dampener and the fuel pump itself won't allow reverse flow. Thats the good news! The work begins with draining the tank, theres a large plug on the bottom of the tank. Drain it out and look for debris. If you have alot you need to flush out the tank and will probably need to remove the sending unit to clean out the gas pick up tube and it's screen. Its a chore but remember you won't have to do it again if you keep the tank clean.
Since you are under the car at this point you can change out the fuel lines and save a hassle later. See other postings about fuel lines (their are not your grandfathers Ford style)
DO NOT EVER, FOR ANY REASON, introduce acetone or any other solvent into the fuel sytem or for that matter coat hangers!
03-19-2004, 11:21 AM
#6
Guest
Posts: n/a
the absolutely longest sentence on zdriver.com
Originally Posted by atczr
Hello to all. I'm new to this forum but not to Z cars. This is my latest find. It's a 78 that's been sitting abandoned for the past ten years. Needless to say it's pretty rough but almost rust free. I took her home on a trailer and changed her oil and filter. Put in new plugs and decided what the heck and put in a battery from one of my other cars and Holy crap. it started!! She didn't smoke and idled pretty smooth at around 700 rpm. This is a five speed car by the way. I couldn't believe it! Ten years and the thing fired up like it was driven yesterday!! Now the problem, well one of many I'm sure. The car ran fine for about five minutes and then died. Now she won't start again. Has no fuel pressure. I've drained the old gas out and replaced the filter. I even changed the pump even though the old one was running. I blew compressed air through the fuel lines from the tank forward. Put in fresh gas (4 gallons). The pump comes on when I turn the ignition on but I'm not getting anything from the fuel line to the rail. The pump runs the whole time the key is on. If I put my finger over the end of the hose with the key on I feel very little pressure and get maybe a couple of teaspoons of gas when I let it go. Is there something I'm missing here??!! I even tried blowing air through the gas lines cominf out of the tank itself. There's two on this car. The top one seemed to be free as I could feel the air coming out through the cap. The bottom one didn't seem to let the air go through. Is this right?? The top line is the one connected to the fuel pump inlet. This looks kind of odd to me because that line is almost halfway up the tank unless the tube extends down inside the tank, otherwise it seems like it would be hard for the pump to pick up the last half tank of fuel! Sorry for being so long but I thought as many details as possible might help. Any ideas on why I can't get any pressure? This is my first fuel injected Z so any ideas would be greatly appreciated. Thanks guys and gals.
03-19-2004, 12:03 PM
#7
Guest
Posts: n/a
Originally Posted by Z*Tech
Its not unusual for a Z to start after long years, they are great feats of engineering, but I think you probably sucked up junk that was sitting in the bottom of the tank.
As you noted there are two lines, the top on being the fuel return line which rarely if ever clogs.
The bottom line is the work horse, you can't blow it backward because the fuel dampener and the fuel pump itself won't allow reverse flow. Thats the good news! The work begins with draining the tank, theres a large plug on the bottom of the tank. Drain it out and look for debris. If you have alot you need to flush out the tank and will probably need to remove the sending unit to clean out the gas pick up tube and it's screen. Its a chore but remember you won't have to do it again if you keep the tank clean.
Since you are under the car at this point you can change out the fuel lines and save a hassle later. See other postings about fuel lines (their are not your grandfathers Ford style)
DO NOT EVER, FOR ANY REASON, introduce acetone or any other solvent into the fuel sytem or for that matter coat hangers!
As you noted there are two lines, the top on being the fuel return line which rarely if ever clogs.
The bottom line is the work horse, you can't blow it backward because the fuel dampener and the fuel pump itself won't allow reverse flow. Thats the good news! The work begins with draining the tank, theres a large plug on the bottom of the tank. Drain it out and look for debris. If you have alot you need to flush out the tank and will probably need to remove the sending unit to clean out the gas pick up tube and it's screen. Its a chore but remember you won't have to do it again if you keep the tank clean.
Since you are under the car at this point you can change out the fuel lines and save a hassle later. See other postings about fuel lines (their are not your grandfathers Ford style)
DO NOT EVER, FOR ANY REASON, introduce acetone or any other solvent into the fuel sytem or for that matter coat hangers!
03-19-2004, 02:12 PM
#8
Registered User
Join Date: Nov 2003
Location: Gerber, CA
Posts: 3,672
Z tech- Dude, the coat hanger is to be used as a feeler in the fuel line. He wouldn't be "introducing" it into the fuel system. It may help the guy find his clog. I didn't think I needed to explain that he wouldn't want to leave it in the fuel line. Hopefully he had enough common sense to remove it. It won't harm anything. You sound like a dentist when they say don't ever put sharp metal objects in your mouth. What's the 1st thing do?....They stick a sharp metal object in your mouth.
03-19-2004, 02:37 PM
#9
Registered User
Join Date: Jan 2004
Location: Seattle, Wa
Posts: 82
no pressure
If you have already pulled the tank, it takes about two minutes to pull the sending unit and have access to the pickup screen.
I had the unfortunate experience of recieving a tankful of sand that came with the gasoline I was buying, seems the storage tank collapsed and sand got into the pumps, Since that time I like keeping the primary screen at the beginning of the pickup tube for safety reasons.
Destruction of the screen would allow any foreign material to enter the fuelpump and they are too expensive for me to take the chance.
I had the unfortunate experience of recieving a tankful of sand that came with the gasoline I was buying, seems the storage tank collapsed and sand got into the pumps, Since that time I like keeping the primary screen at the beginning of the pickup tube for safety reasons.
Destruction of the screen would allow any foreign material to enter the fuelpump and they are too expensive for me to take the chance.
03-19-2004, 03:09 PM
#10
Registered User
Join Date: Jan 2004
Location: Seattle, Wa
Posts: 82
Originally Posted by 91zxtt
Z tech- Dude, the coat hanger is to be used as a feeler in the fuel line. He wouldn't be "introducing" it into the fuel system. It may help the guy find his clog. I didn't think I needed to explain that he wouldn't want to leave it in the fuel line. Hopefully he had enough common sense to remove it. It won't harm anything. You sound like a dentist when they say don't ever put sharp metal objects in your mouth. What's the 1st thing do?....They stick a sharp metal object in your mouth.
The possiblity of foreign matter finding its way past the fuel pump and dampner is, well, not a reality. Objects the size if 1.5mm or larger are large enough to stop the fuelpump and certainly not large enough to plug the fuel line.
I believe my suspecting a clogged screen in the fuel tank to be the most likely
candidate.
The difference between a dentist and the rest of us is that the dentist has training and education as to where the sharp object goes.
03-19-2004, 05:28 PM
#11
Registered User
Join Date: Nov 2003
Location: Gerber, CA
Posts: 3,672
Originally Posted by Z*Tech
The difference between a dentist and the rest of us is that the dentist has training and education as to where the sharp object goes.
Pretty much anything can happen when a car sits for that long.
I do agree with you on the clogged screen idea though.
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