Fuel line pulsator leak????????
Thread Starter
Instructor
Joined: Sep 2005
Posts: 145
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From: South Florida
Fuel line pulsator leak????????
I have a 1988 and seem to have a fuel leak. About 2 weeks ago I parked the car and the next day I found a small puddle of gas under the car. When I looked I saw it was dripping from the front passenger side of the motor. It appeared to coming from a connection block that the steel fuel line went through on the front of the motor. It leaked for about a day and a half and then just stopped. I took it to my mechanic and he said it was a leak in the fuel line pulsator. Of course this has been discontinued by GM. Any idea of the actual name of this part and where I can get one?
Racer
Joined: May 2004
Posts: 295
Likes: 3
From: Newton NJ
My understanding of the fuel system has the pulsator in the tank just after the fuel pump. My thought is that you have a leak in your fuel line. There is a fuel line that runs near the front passenger wheel, that has a small section of rubber line for vibration, which will leak. You can find this line by following it just after the fuel filter. It will then change back to steel near the fuel rail of the motor. Alot folks of have problems with leaks there.
Hope this helps
cmontel
Hope this helps
cmontel
Large Impressive Member
Joined: Jul 2003
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From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
My understanding of the fuel system has the pulsator in the tank just after the fuel pump. My thought is that you have a leak in your fuel line. There is a fuel line that runs near the front passenger wheel, that has a small section of rubber line for vibration, which will leak. You can find this line by following it just after the fuel filter. It will then change back to steel near the fuel rail of the motor. Alot folks of have problems with leaks there.
Hope this helps
cmontel
Hope this helps
cmontel
Unless there's something different that I don't know on an early C4, the pulsator is in the tank. If there's a rubber section in that area as cmontel indicated, it's likely garbage after all of these years.
Thread Starter
Instructor
Joined: Sep 2005
Posts: 145
Likes: 0
From: South Florida
Thanks for the suggestions. Here is what I find when I really looked close this morning. There are 2 steel fuel lines coming from the fuel rail area. They go down the front of the motor on the passenger side. I need to look between the ac compressor and the water pump to see them. One goes through what appears to be a rectangular block with a round piece behind it. It seems to be part of the steel line.This is where the leak is. I suspect there is a diaphram in the round piece that is leaking. This is the piece I need. In the GM Service Manual I see in the Fuel System Diagnosis section chart (A-7 page 6E3-A-19) a reference to a "leaking pump coupling hose or pulsator". I cannot find any pictures or any other reference to the pulsator. I think I need the pulsator. Is anyone familiar with this part? Does anyone know a GM part number or where I can get one of these?
Any help would be much appreciated.
Thanks,
Rich
Any help would be much appreciated.
Thanks,
Rich
Pro
Joined: May 2002
Posts: 541
Likes: 2
From: Kalama WA
If you are insistant that it is a pulsator valve, it is located in the fuel tank between the fuel pump assembly -part # AcDelco p/n FP27. It is used to quiet down injector noise (pulsating rattle on the fuel return lines). I doubt this is your leak you are describing. I would check your rubber fuel lines that transition from the steel fuel lines (at the frame -front) up to the plenum. There have been many engine fires due to cracked fuel line in engine compartment of vettes.
Team Owner
Joined: Jan 2003
Posts: 20,324
Likes: 250
From: Summerland B.C. Canada
As mentioned a few times, the pulsator damper is in the tank, directly above pump. The only thing on the lower right corner of my motor, is a strap around fuel lines that is bolted to block.
If your looking in the manual, why not look in the fuel section.
All the pics are there.
http://members.shaw.ca/agent86/Engine%20Fuel.pdf
If your looking in the manual, why not look in the fuel section.
All the pics are there.
http://members.shaw.ca/agent86/Engine%20Fuel.pdf
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
My 86 doesn't have this, but when I was looking for the fuel lines that run from the fuel rail to the fuel filter...I ordered a set from a later model L98. These lines were the same size and had a square block (dampner) on either the feed line or the return line. I had to return it and get the fuel lines for a 86. I know what your describing 88 Coupe, but not sure if the o-rings (if any) can be replaced or if you have to purchase another set of fuel lines. Either way you will have to remove the rail to filter lines to get to it.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
Dan, your link doesn't show what the OP is describing. Apparently it came on the 88-91 Corvettes. My 86 doesn't have it and not sure of the 87.
I tried to fit the later style fuel line on my 86, but would not go because of the AC bracket (not enough room).
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Thread Starter
Instructor
Joined: Sep 2005
Posts: 145
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From: South Florida
Thanks guys, I appreciate all the help.
RRT, where did you order the lines from? I don't think there are any O rings, I don't see any fittings at the top or the bottom of the block either. It seems like it is all part of the line.
The funny thing is I can't find any picture or references in the manual under any section.
Again, thanks for your help.
RRT, where did you order the lines from? I don't think there are any O rings, I don't see any fittings at the top or the bottom of the block either. It seems like it is all part of the line.
The funny thing is I can't find any picture or references in the manual under any section.
Again, thanks for your help.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
It's been about a year since I replaced these lines. It can be done with the engine in. You just have to loosen alot of items and snake it through from the top. Make sure not to force anything....the hold down clamps won't work if they are bent and this will cause rattling and possible fuel leak.
Have away to drain and catch the fuel when you loosen the lines at the fuel filter. When you get a new/used set of lines, make sure they are the exact same shape as the old ones. This is where I had a problem and had to redo everything. Buy new o-rings for the line to rail connections and go ahead and replace the fuel filter since you will break the seal on the old one.
IIRC, I got the first set of lines from Contemporarycorvette....that were like what you needed. I called a good many places around the US and they ranged from $75 for one line to $200 for both plus shipping.
I found a fellow in Texas (scarabexc...a forum member) had the feed and return line from the filter to the rail for $60 shipped that fit my 86. Needed lots of cleaning (oil), but the lines and rubber were in good shape.
If you need any more info on the removal and install or more info about scarabexc....let me know. He parts out 84-89 Corvettes and sells things on ebay too.
Have away to drain and catch the fuel when you loosen the lines at the fuel filter. When you get a new/used set of lines, make sure they are the exact same shape as the old ones. This is where I had a problem and had to redo everything. Buy new o-rings for the line to rail connections and go ahead and replace the fuel filter since you will break the seal on the old one.
IIRC, I got the first set of lines from Contemporarycorvette....that were like what you needed. I called a good many places around the US and they ranged from $75 for one line to $200 for both plus shipping.
I found a fellow in Texas (scarabexc...a forum member) had the feed and return line from the filter to the rail for $60 shipped that fit my 86. Needed lots of cleaning (oil), but the lines and rubber were in good shape.
If you need any more info on the removal and install or more info about scarabexc....let me know. He parts out 84-89 Corvettes and sells things on ebay too.
Instructor
Joined: Dec 2006
Posts: 139
Likes: 0
From: Deep in The Heart of Dixie
My 86 doesn't have this, but when I was looking for the fuel lines that run from the fuel rail to the fuel filter...I ordered a set from a later model L98. These lines were the same size and had a square block (dampner) on either the feed line or the return line. I had to return it and get the fuel lines for a 86. I know what your describing 88 Coupe, but not sure if the o-rings (if any) can be replaced or if you have to purchase another set of fuel lines. Either way you will have to remove the rail to filter lines to get to it.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
A fuel pulsation damper. FPD
It is used a lot in imports and the end of the fuel rail. this diaphragm release waves or pressure spikes from the fuel pump. These pressure spikes are hard on the injectors.
Many of the other makes are having real problems with these as they age and crack. Many cars are being lost to engine compartment fires.
One solution is to move to banjo bolt modifications and completely do away with the FPD
Caution, By clicking the following link you may be subjected to entering a "Ricer" forum. I accept no responsibility for what may happen to you next........
http://www.rx7club.com/showthread.php?t=395021
One thing I'll say about the Rotary crowd, they are innovative and out of the box thinkers.
It is used a lot in imports and the end of the fuel rail. this diaphragm release waves or pressure spikes from the fuel pump. These pressure spikes are hard on the injectors.
Many of the other makes are having real problems with these as they age and crack. Many cars are being lost to engine compartment fires.
One solution is to move to banjo bolt modifications and completely do away with the FPD
Caution, By clicking the following link you may be subjected to entering a "Ricer" forum. I accept no responsibility for what may happen to you next........
http://www.rx7club.com/showthread.php?t=395021
One thing I'll say about the Rotary crowd, they are innovative and out of the box thinkers.
Le Mans Master
Joined: Feb 2006
Posts: 8,753
Likes: 9
From: Louisiana
