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Fuel filter/pressure problem?

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
My 96 won't start. I tried to release the pressure at the fuel rail and nothing happened.I did this within 60 seconds after turning the ignition to the run position,I assumed that since there was no pressure at the fuel rail, either the filter or pump was bad.The Vette has 175K on it and I have no idea when anything was replaced, if ever.How difficult is it to replace the fuel filter on my 96 LT-4? Any special tools required? Any help would be appreciated, MiMitch
 

Ghost~3~

Well-known member
Joined
Oct 18, 2003
Messages
81
Location
So.San Francisco Ca.
Corvette
1985 Blue Coupe
Not "Sure" if your filter is located in the SAME place as on my '87???

On mine, it's located on the right side frame rail about where the starter would be on the engine.

Going on your Mile's, chance's are it's the Pump, but a NEW Clean Filter is CHEAP
Insurance, and you get to have "FUN" finding Your's! :upthumbs;LOL

If ya don't have any Service manual's?? get down to your local part's store and GET ONE!! A Chilton's will get ya thru most thing's, and will tell ya where a LOT of stuff is located. :ugh :D
 

Robertwav1

Well-known member
Joined
Jan 7, 2003
Messages
822
Location
Ocala, Florida
Corvette
1993 Blue
One thing I learned was to make sure the gas tank is very low. If you don't you will have fuel running down your arm the whole time. Pull the fuse for the fuel pump of course. Watch the little o-ring thingies on the fuel lines ... they have to go back or better yet there so frail you may want to have new ones on hand. I agree, replacing the filter is must even if that's not the problem.
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Thanks for all the input. I loosened the in-let side of fuel line from the filter. I then turned the key to the run position. There was no fuel leakage near the fitting or ony evidence of any fuel. So I'm assuming it has to be the pump.
Getting back to the filter. Does anyone have any suggestions concerning removing the fuel line from the outlet side of the filter? it seems that the exhaust system doesn't allow access to the fittings. Any and all help is greatly appreciated. By the way I have to do this in a carport, which makes everything more difficult. Again , thanks for all your help, MiMitch
 

Ghost~3~

Well-known member
Joined
Oct 18, 2003
Messages
81
Location
So.San Francisco Ca.
Corvette
1985 Blue Coupe
Well Mitch, apparently there's ENOUGH of a differance between our car's "YEAR'S"
wise, that I'd better let someone with a LATE MODEL C-4 help ya as mine is not too hard to change....You may have some stuff in the way, I don't have to deal with on mine??? ;shrug
 

Robertwav1

Well-known member
Joined
Jan 7, 2003
Messages
822
Location
Ocala, Florida
Corvette
1993 Blue
I remember you need to loosen the fuel lines from up in the engine compartment back to where the fuel filter is and a little bit further back. This allows more movement and clearence however, from what I can recall you need to have the fuel line wrenches. The ones that are like a box wrench but it's cutout to allow slipping it over the fuel line. Even with this it's tight but there is enough room. My thing when making any type of repairs on these cars is to move stuff out of your way or loosen things for more room.
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Fuel filter/pressure problem

3rd. attempt in trying to repl. Obviously, me and computers don't see eye to eyeon how they should work. Again, happy 4th of July to everyone.
My fuel filter is mounted to the frame (?) rail where it curves up and towards the engine. Clearance for the tire.Directly across from the filter, securley mounted to the exhaust pipe, is an object(catalytic conv. ?) with a heat shield. From the engine compartment, the fuel lines are secured to the inner panel and are accessable. Following the fuel lines, where they bend toward the filter, it feels like a rubber gromet with a tab surrounding the fuel lines. Is this gromet attached to the inner panel or just resting(?) against it and being used as a vibration dampener?
It doesn't appear to be enough room to get a tube wrench(s) in there. By loosening the fuel lines, does that give you enough room to maneuver the filter to gain access to the top fittings?
Again, all and help is appreciated, MiMitch
 

G Winter

Well-known member
Joined
Aug 21, 2004
Messages
2,177
Location
NW Iowa
Corvette
1990 red convert 6 sp
I understand that you loosened the inlet fittings on the filter and with the key on you had no leakage. The first thing to do is check fuses. I believe all have a fuel pump relay, check that. If you varifie that you have current to the fuel pump odds are the pump has gone out.

Glenn
:w
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Fuel filter/pressure problem

I understand that you loosened the inlet fittings on the filter and with the key on you had no leakage. The first thing to do is check fuses. I believe all have a fuel pump relay, check that. If you varifie that you have current to the fuel pump odds are the pump has gone out.

Glenn
:w

That was one of the first things that I did. That, and I made sure there was gas in the tank. It was half full and no bad fuses. Is it possible to check the current to the fuel pump without me blowing myself and the car up?
Thanks for the help, MiMitch
 

G Winter

Well-known member
Joined
Aug 21, 2004
Messages
2,177
Location
NW Iowa
Corvette
1990 red convert 6 sp
The pump should run a few seconds when you turn the key on. Have someone turn on the key when you are at the tank and listen closely,should be able to hear the pump.Did you check at the relay?
I don't know if there is a plug on the outside of the pump.

Glenn
:w
 

Robertwav1

Well-known member
Joined
Jan 7, 2003
Messages
822
Location
Ocala, Florida
Corvette
1993 Blue
3rd. attempt in trying to repl. Obviously, me and computers don't see eye to eyeon how they should work. Again, happy 4th of July to everyone.
My fuel filter is mounted to the frame (?) rail where it curves up and towards the engine. Clearance for the tire.Directly across from the filter, securley mounted to the exhaust pipe, is an object(catalytic conv. ?) with a heat shield. From the engine compartment, the fuel lines are secured to the inner panel and are accessable. Following the fuel lines, where they bend toward the filter, it feels like a rubber gromet with a tab surrounding the fuel lines. Is this gromet attached to the inner panel or just resting(?) against it and being used as a vibration dampener?
It doesn't appear to be enough room to get a tube wrench(s) in there. By loosening the fuel lines, does that give you enough room to maneuver the filter to gain access to the top fittings?
Again, all and help is appreciated, MiMitch

In ref to your filter change, remove the clamps on the fuel lines, take the bolt out that attaches the clamp that holds the lines. There are a few you have to do, the more you take off the more the fuel lines will give. Mine is mounted the same way, points a little upward. Release the fuel lines up in the engine compartment also then they can be moved enough to do the job. Good Luck!
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Fuel filter/pump problem.

Ever time I try to reply it says that I'm not logged in, yet I can access everything. Oh well, such is life.
Thanks everyone for your help. I'll try to get to the fuel filter later when the sun goes down a little.
Is the gromet, in the engine compartment, where the fuel lines turn toward the filter, attached to the panel? I can feel the gromet but can't see an attachment screw/nut.It feels like there is a tab/clip holding the lines together but nothing solid like a screw/nut. Again all your help is greatly appreciated. MiMitch
 

Robertwav1

Well-known member
Joined
Jan 7, 2003
Messages
822
Location
Ocala, Florida
Corvette
1993 Blue

Well ... again from memory, the clips that hold the fuel lines together along the rocker panel do come off with some type of fastener, In the engine compartment the clamps that hold the fuel lines together and mount to the block must be taken off. Everything is accessible. I don't remember struggling anywhere above the fuel filter other then under the hood? Hope this helps.

Also, some of the forums I belong to do not auto log you in. Sometimes when cookies are allowed, depending on your browsers settings as well as the forums having a check mark for "remembering you" will you're log in be remembered. Hope this helps.
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Fuel filter/pump problem

Well ... again from memory, the clips that hold the fuel lines together along the rocker panel do come off with some type of fastener, In the engine compartment the clamps that hold the fuel lines together and mount to the block must be taken off. Everything is accessible. I don't remember struggling anywhere above the fuel filter other then under the hood? Hope this helps.

Also, some of the forums I belong to do not auto log you in. Sometimes when cookies are allowed, depending on your browsers settings as well as the forums having a check mark for "remembering you" will you're log in be remembered. Hope this helps.

I didn't get a chance to work on the Vette yesterday or today. I did take a look and saw the retainers for the fuel lines under the car along the frame. I did feel a screw that holds the filter to the frame. I hope to work on the Vette Fri. evening and Sat. ,early morning and late afternoon. Working in the sun on the blacktop of the un-shaded carport isn't as much fun as I remember. Again thanks for the help, MiMitch
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
fuel filter/oump problem

Over the last few days I've spent over an hour trying to remove the d___ fuel filter. I've loosened and removed all the clips that I could see from the engine compartment and all along the frame rail. I still can't get to the upper fitting to loosen it. I've tried using the tubing wrench and open end wrench and there is no room to get them in there. If I remove the wheel well panel from around the front tire, will that give me access to the fuel filter? Again, all and any help is very greatly appreciated, MiMitch.
 

WILLFEOM

Member
Joined
Nov 21, 2005
Messages
21
Location
ST LOUIS
Corvette
1996 BLACK COUPE
fuel pump

Sorry about your trouble with the filter. I have a 1996 and just went thru the trouble of changing the fuel pump. Actually it is easier than the filter. If you cannot hear the pump run when you turn on the key I can almost guarantee it is the pump. After you change it their will be no doubt the pump is running. This is an easy 30min. job. Be sure to disconnect the battery before changing pump
 

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
One thing I would check before putting in a fuel pump is the TPS. If it is bad it tells the ECM to shut off the fuel and the ECM will not let the power go to the pump or injectors. Here is the process for checking the TPS.

Throttle Position Sensor (TPS)
Copied from 1993 Service Manual
The Throttle Position sensor (TPS) is a potentiometer connected to the throttle shaft on the throttle body. It is a potentiometer with one end connected to 5 volts from the ECM and the other to ECM ground. A third wire is connected to the ECM to measure the voltage from the TP sensor. As the throttle valve angle is changed (accelerator pedal moved), the voltage output of the TP sensor also changes. At a closed throttle position, the voltage output of the TP sensor is low (approximately .5 volt). As the throttle valve opens, the output voltage should be approximately 5 volts.

By monitoring the output voltage from the TP sensor, the ECM can determine fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor can cause intermittent burst of fuel from the injectors and cause an unstable idle, because the ECM detects the throttle is moving.

If the TP sensor circuit is open, the ECM will set a DTC 22. If the TP sensor circuit is shorted a DTC 21 will be set. A problem in any of the TP sensor circuits will set either a DTC 21 or 22. Once a DTC is set, the ECM will use a default value for TP sensor, and some vehicle performance will return.

A personal note, when my TPS failed it DID NOT set a code other than to tell me the ECM was bad.;shrug

 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Fuel filter/pump problem

Over the last few days I've spent over an hour trying to remove the d___ fuel filter. I've loosened and removed all the clips that I could see from the engine compartment and all along the frame rail. I still can't get to the upper fitting to loosen it. I've tried using the tubing wrench and open end wrench and there is no room to get them in there. If I remove the wheel well panel from around the front tire, will that give me access to the fuel filter? Again, all and any help is very greatly appreciated, MiMitch.

While checking my e-mail I had a reply from my sister of all people. She knew I was having a problem wirh the filter and sent me a link to another site.Well I read the replies and it was a very simple solution.I dis-connected the lower fuel line fitting. I cut down a 5/8(16mm) open end wrench to fit the space available for the upper fuel line and connected it to the fitting. I then took a 13/16 (approx.20mm) spark plug socket to the lower fuel filter fitting, which was accessable, and un-screwed it. It came off suprisingly easy.

I would like to thank all who have given their advice and support over the last week or so.

MiMitch
 

MiMitch

Well-known member
Joined
Oct 17, 2004
Messages
48
Location
Greater Deatroit, Mi.
Corvette
1996 Coupe
Fuel filter/pump problem

Sorry about your trouble with the filter. I have a 1996 and just went thru the trouble of changing the fuel pump. Actually it is easier than the filter. If you cannot hear the pump run when you turn on the key I can almost guarantee it is the pump. After you change it their will be no doubt the pump is running. This is an easy 30min. job. Be sure to disconnect the battery before changing pump

I probably will be tackling the fuel pump next. I finally did get the filter off and gave a brief discription of how I (we) did it.

Again I would like to thank everyone for all the advice and support given to me.With everyone's suggestions and ideas I was able to replace the filter. Thank you all very much, MiMitch
 

Robertwav1

Well-known member
Joined
Jan 7, 2003
Messages
822
Location
Ocala, Florida
Corvette
1993 Blue
Good Job! The stubby wrenches are a valuable tool for this car, they are no longer then your fist so that fit anywhere your hand will. :beer
 

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